Analytica Chimica Acta最新文献_第2页

SagMSI: A graph convolutional network framework for precise spatial segmentation in mass spectrometry imaging

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344098

Mudassir Shah , Linlin Wang , Lei Guo , Chengyi Xie , Thomas Ka-Yam Lam , Lingli Deng , Xiangnan Xu , Jingjing Xu , Jiyang Dong , Zongwei Cai

Background

Mass Spectrometry Imaging (MSI) is a label-free imaging technique used in spatial metabolomics to explore the distribution of various metabolites within biological tissues. Spatial segmentation plays a crucial role in the biochemical interpretation of MSI data, yet the inherent complexity of the data—characterized by large size, high dimensionality, and spectral nonlinearity—poses significant analytical challenges in MSI segmentation. Although deep learning approaches based on convolutional neural networks (CNNs) have shown considerable success in spatial segmentation for biomedical imaging, they often struggle to capture the comprehensive structural information of MSI data.

Results

We propose SagMSI, an unsupervised graph convolution network (GCN)-based segmentation strategy that combines spatial-aware graph construction of MSI data with a GCN module within a deep neural network. This approach enables flexible, effective, and precise spatial segmentation. We applied SagMSI to both simulated data and various MSI experimental datasets and compared its performance against three commonly used segmentation methods, including t-SNE + k-means, a pipeline implemented by the R package Cardinal, and a CNN-based segmentation method. Visual comparisons with histological images and quantitative evaluations using the silhouette coefficient and adjusted rand index demonstrate that SagMSI excels in segmenting complex tissues, revealing detailed sub-structures, and delineating distinct boundaries of sub-organs with minimal noise interference. The integration of graph-based neural networks with spatially structural information offers deeper insights into spatial omics.

Significance

The MSI data is modelled by graph structure so as to incorporate the biomolecular profiling and spatial adjacency within neighboring pixels. The GCN framework generates meaningful pixel representations by learning local and global contextual information through the graph-based structure, thus enabling precise segmentation of MSI. The approach demonstrated high flexibility, robustness to noise, and applicability in exploring complex tissue structures and identifying marker ions associated with microregions.

{"title":"SagMSI: A graph convolutional network framework for precise spatial segmentation in mass spectrometry imaging","authors":"Mudassir Shah , Linlin Wang , Lei Guo , Chengyi Xie , Thomas Ka-Yam Lam , Lingli Deng , Xiangnan Xu , Jingjing Xu , Jiyang Dong , Zongwei Cai","doi":"10.1016/j.aca.2025.344098","DOIUrl":"10.1016/j.aca.2025.344098","url":null,"abstract":"<div><h3>Background</h3><div>Mass Spectrometry Imaging (MSI) is a label-free imaging technique used in spatial metabolomics to explore the distribution of various metabolites within biological tissues. Spatial segmentation plays a crucial role in the biochemical interpretation of MSI data, yet the inherent complexity of the data—characterized by large size, high dimensionality, and spectral nonlinearity—poses significant analytical challenges in MSI segmentation. Although deep learning approaches based on convolutional neural networks (CNNs) have shown considerable success in spatial segmentation for biomedical imaging, they often struggle to capture the comprehensive structural information of MSI data.</div></div><div><h3>Results</h3><div>We propose SagMSI, an unsupervised graph convolution network (GCN)-based segmentation strategy that combines spatial-aware graph construction of MSI data with a GCN module within a deep neural network. This approach enables flexible, effective, and precise spatial segmentation. We applied SagMSI to both simulated data and various MSI experimental datasets and compared its performance against three commonly used segmentation methods, including <em>t</em>-SNE + <em>k-</em>means, a pipeline implemented by the R package Cardinal, and a CNN-based segmentation method. Visual comparisons with histological images and quantitative evaluations using the silhouette coefficient and adjusted rand index demonstrate that SagMSI excels in segmenting complex tissues, revealing detailed sub-structures, and delineating distinct boundaries of sub-organs with minimal noise interference. The integration of graph-based neural networks with spatially structural information offers deeper insights into spatial omics.</div></div><div><h3>Significance</h3><div>The MSI data is modelled by graph structure so as to incorporate the biomolecular profiling and spatial adjacency within neighboring pixels. The GCN framework generates meaningful pixel representations by learning local and global contextual information through the graph-based structure, thus enabling precise segmentation of MSI. The approach demonstrated high flexibility, robustness to noise, and applicability in exploring complex tissue structures and identifying marker ions associated with microregions.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344098"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ion mobility spectrometer with heated sample inlet - Solution to the issue of temperature effect on resolving power

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344097

Martin Lippmann, Moritz Hitzemann, Timo Sawatzki, Jonas Winkelholz, Alexander Nitschke, Tim Kobelt, Stefan Zimmermann

Background

One major challenge in detecting less volatile compounds with an ion mobility spectrometer (IMS) is preventing condensation of target molecules in the sampling line and ionization region to allow for fast response and recovery. Heating the entire device including the sampling line can of course mitigate condensation of such compounds, but this comes at the cost of reduced resolving power and compromised detection limits. Furthermore, a considerable amount of additional power and an IMS design with temperature-resistant components are needed.

Results

In this work, a different approach has been investigated, with a heated sample inlet in combination with a directed sample gas flow through the ionization region, but with the drift region at lower temperature. While this approach effectively addresses the issue of condensation, it results in an inhomogeneous temperature distribution within the drift region. Simulations and experimental data reveal that this uneven temperature distribution can significantly distort the peaks in the ion mobility spectrum, depending on the IMS orientation. However, positioning the IMS vertically, with the detector facing down, significantly minimizes temperature-induced peak distortion, thereby maintaining high resolving power. In this orientation, the IMS used in this work shows a resolving power of 80, while the IMS sample inlet and outlet are heated to 423 K. In addition, a directed sample gas flow in the ionization region is used to further reduce condensation in the ionization region.

Significance and novelty

The approach and findings revealed in this work allow the construction of IMS with a heated sample inlet to prevent condensation of less volatile compounds while also maintaining the high resolving power of a drift tube at room temperature. The results on the influence of the orientation of the IMS can also be applied to even higher temperatures.

{"title":"Ion mobility spectrometer with heated sample inlet - Solution to the issue of temperature effect on resolving power","authors":"Martin Lippmann, Moritz Hitzemann, Timo Sawatzki, Jonas Winkelholz, Alexander Nitschke, Tim Kobelt, Stefan Zimmermann","doi":"10.1016/j.aca.2025.344097","DOIUrl":"10.1016/j.aca.2025.344097","url":null,"abstract":"<div><h3>Background</h3><div>One major challenge in detecting less volatile compounds with an ion mobility spectrometer (IMS) is preventing condensation of target molecules in the sampling line and ionization region to allow for fast response and recovery. Heating the entire device including the sampling line can of course mitigate condensation of such compounds, but this comes at the cost of reduced resolving power and compromised detection limits. Furthermore, a considerable amount of additional power and an IMS design with temperature-resistant components are needed.</div></div><div><h3>Results</h3><div>In this work, a different approach has been investigated, with a heated sample inlet in combination with a directed sample gas flow through the ionization region, but with the drift region at lower temperature. While this approach effectively addresses the issue of condensation, it results in an inhomogeneous temperature distribution within the drift region. Simulations and experimental data reveal that this uneven temperature distribution can significantly distort the peaks in the ion mobility spectrum, depending on the IMS orientation. However, positioning the IMS vertically, with the detector facing down, significantly minimizes temperature-induced peak distortion, thereby maintaining high resolving power. In this orientation, the IMS used in this work shows a resolving power of 80, while the IMS sample inlet and outlet are heated to 423 K. In addition, a directed sample gas flow in the ionization region is used to further reduce condensation in the ionization region.</div></div><div><h3>Significance and novelty</h3><div>The approach and findings revealed in this work allow the construction of IMS with a heated sample inlet to prevent condensation of less volatile compounds while also maintaining the high resolving power of a drift tube at room temperature. The results on the influence of the orientation of the IMS can also be applied to even higher temperatures.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344097"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Porous platinum nanozyme-amplified capacitance immunoassay for alpha-fetoprotein with hepatocellular carcinoma on an interdigitated gold micro-comb array

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344101

Huaxi Ma , Dongqing Zhang , Ting Lin , Shenglong Lin, Wenjun Wu, Ziyuan Liao, Xiangmei Wang, Haibing Gao

Background

Hepatocellular carcinoma, one of the most common malignancies, is the worldwide three cause leading the mortality of cancers. Alpha-fetoprotein (AFP) is a typical tumor marker for the recurrences of HCC, and can be utilized potentially during routine follow-up after HCC resection. Therefore, sensitive and accuracy detection of AFP is very critical at the early stage of hepatocellular carcinoma.

Results

In this work, an in-situ amplified capacitance immunoassay was designed for highly sensitive determination of AFP in biological fluids. The capacitance immunosensor was fabricated by means of immobilizing anti-AFP capture antibodies on an interdigitated gold micro-comb array through a carbodiimide coupling method. Porous platinum nanoparticles (PtNPs) were used for the labeling of anti-AFP detection antibody. The presence of target analyte induced the formation of the sandwiched immunocomplex between capture antibody and detection antibody. The carried porous PtNPs with peroxidase-like activity catalyzed 4-chloro-1-naphethol oxidation to produce an insoluble benzo-4-chlorohexadienone precipitation in the presence of hydrogen peroxide. The precipitation was coated on the micro-comb electrode, thus causing the capacitance change. Two labeling protocols including porous PtNPs and solid PtNPs were investigated for determination of AFP, and improved analytical features were acquired with porous PtNPs. Under optimal conditions, porous PtNP-based capacitance immunoassay gave a good linear response from 0.01 ng mL⁻¹ to 300 ng mL⁻¹ AFP with a detection limit of 7.4 pg mL⁻¹. Good reproducibility, high specificity and long-term stability were also achieved. In addition, 15 human serum specimens were determined through our method, and the results were in accordance with those obtained from commercial AFP enzyme-linked immunosorbent assay.

Significance

This capacitance immunoassay offers promise for sensitive and cost-effective detection of cancer biomarkers without the requirement of natural enzymes. Importantly, porous PtNP-based labeling strategy opens a new horizon for advanced development of capacitance immunoassays.

{"title":"Porous platinum nanozyme-amplified capacitance immunoassay for alpha-fetoprotein with hepatocellular carcinoma on an interdigitated gold micro-comb array","authors":"Huaxi Ma , Dongqing Zhang , Ting Lin , Shenglong Lin, Wenjun Wu, Ziyuan Liao, Xiangmei Wang, Haibing Gao","doi":"10.1016/j.aca.2025.344101","DOIUrl":"10.1016/j.aca.2025.344101","url":null,"abstract":"<div><h3>Background</h3><div>Hepatocellular carcinoma, one of the most common malignancies, is the worldwide three cause leading the mortality of cancers. Alpha-fetoprotein (AFP) is a typical tumor marker for the recurrences of HCC, and can be utilized potentially during routine follow-up after HCC resection. Therefore, sensitive and accuracy detection of AFP is very critical at the early stage of hepatocellular carcinoma.</div></div><div><h3>Results</h3><div>In this work, an <em>in-situ</em> amplified capacitance immunoassay was designed for highly sensitive determination of AFP in biological fluids. The capacitance immunosensor was fabricated by means of immobilizing <em>anti</em>-AFP capture antibodies on an interdigitated gold micro-comb array through a carbodiimide coupling method. Porous platinum nanoparticles (PtNPs) were used for the labeling of <em>anti</em>-AFP detection antibody. The presence of target analyte induced the formation of the sandwiched immunocomplex between capture antibody and detection antibody. The carried porous PtNPs with peroxidase-like activity catalyzed 4-chloro-1-naphethol oxidation to produce an insoluble benzo-4-chlorohexadienone precipitation in the presence of hydrogen peroxide. The precipitation was coated on the micro-comb electrode, thus causing the capacitance change. Two labeling protocols including porous PtNPs and solid PtNPs were investigated for determination of AFP, and improved analytical features were acquired with porous PtNPs. Under optimal conditions, porous PtNP-based capacitance immunoassay gave a good linear response from 0.01 ng mL<sup>−1</sup> to 300 ng mL<sup>−1</sup> AFP with a detection limit of 7.4 pg mL<sup>−1</sup>. Good reproducibility, high specificity and long-term stability were also achieved. In addition, 15 human serum specimens were determined through our method, and the results were in accordance with those obtained from commercial AFP enzyme-linked immunosorbent assay.</div></div><div><h3>Significance</h3><div>This capacitance immunoassay offers promise for sensitive and cost-effective detection of cancer biomarkers without the requirement of natural enzymes. Importantly, porous PtNP-based labeling strategy opens a new horizon for advanced development of capacitance immunoassays.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344101"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

How Excitation-Emission Matrices Have Revolutionised Multi-Way Data Analyses – A tutorial for multi-way EEM-based calibration method developments

IF 6.2 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344089

Marina Antonio, Arsenio Muñoz de la Peña, Héctor C. Goicoechea, Mirta R. Alcaraz

For many years, excitation-emission matrix (EEM) fluorescence spectroscopy has been a compelling analytical technique, fostering the development of multidimensional data analysis-based methods. Its applications span diverse fields, including analytical chemistry and biological, food, and environmental sciences, which have been extensively documented in the scientific literature. EEM spectroscopy stands out for its versatility, affordability, and exceptional capacity to provide rich analytical insights, making it a preferred choice for investigations requiring higher-order data analysis. While second-order data analysis based on EEM fluorescence spectroscopy has been widely explored, generating third-order data from EEM remains a challenging and spotlighted research area.This tutorial intends to trace the evolution of multi-way data analysis in recent years, focusing on applying multidimensional fluorescence in analytical contexts. It delves into the critical issues, emerging trends, and challenges in analytical calibration method developments. Moreover, our comprehensive assessment encompasses the instrumental, methodological, and practical aspects of multi-way data applications, providing tailored guidance to empower readers in overcoming obstacles and advancing their research endeavours.

{"title":"How Excitation-Emission Matrices Have Revolutionised Multi-Way Data Analyses – A tutorial for multi-way EEM-based calibration method developments","authors":"Marina Antonio, Arsenio Muñoz de la Peña, Héctor C. Goicoechea, Mirta R. Alcaraz","doi":"10.1016/j.aca.2025.344089","DOIUrl":"https://doi.org/10.1016/j.aca.2025.344089","url":null,"abstract":"For many years, excitation-emission matrix (EEM) fluorescence spectroscopy has been a compelling analytical technique, fostering the development of multidimensional data analysis-based methods. Its applications span diverse fields, including analytical chemistry and biological, food, and environmental sciences, which have been extensively documented in the scientific literature. EEM spectroscopy stands out for its versatility, affordability, and exceptional capacity to provide rich analytical insights, making it a preferred choice for investigations requiring higher-order data analysis. While second-order data analysis based on EEM fluorescence spectroscopy has been widely explored, generating third-order data from EEM remains a challenging and spotlighted research area.This tutorial intends to trace the evolution of multi-way data analysis in recent years, focusing on applying multidimensional fluorescence in analytical contexts. It delves into the critical issues, emerging trends, and challenges in analytical calibration method developments. Moreover, our comprehensive assessment encompasses the instrumental, methodological, and practical aspects of multi-way data applications, providing tailored guidance to empower readers in overcoming obstacles and advancing their research endeavours.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"108 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spatial distribution analysis of secondary metabolites in bolted and unbolted Saposhnikovia divaricata by atmospheric pressure laser ablation carbon fiber ionization mass spectrometry imaging

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344096

Na Li , Xialian Cui , Yingjie Lu , Fang Zhang , Su Guo , Yue Su , Yinlong Guo

Background

Bolting severely affects the medicinal value and yield of Saposhnikovia divaricata. Currently, spatial distribution of secondary metabolites in bolted and unbolted Saposhnikovia divaricata remains unknown. The commercial Mass spectrometry imaging (MSI) platforms has high sensitivity to high-polar compounds, but suppresses signals of less polar compounds, generating a gap of understanding how spatial distributed of such metabolites that is less prone to ionize.

Results

This study developed a highly sensitive Laser Ablation Carbon Fiber Ionization (LACFI) MSI method under atmospheric pressure to achieve the spatial distribution analysis of secondary metabolites in Saposhnikovia divaricata, including low-polar compounds which is difficult to be analyzed in other MSI methods. The laser efficiently desorbs compounds from Saposhnikovia divaricata tissue, and the desorbed compounds are rapidly ionized by a carbon fiber ion source under high pressure. The desorption and ionization are performed in two separate steps, reducing the matrix effect and enhancing the ionization efficiency of compounds, which increase sensitivity. The carbon fiber has good compatibility with polar and low-polar compounds, which increases the number of detectable metabolites. The spatial distribution of secondary metabolites undergoes a shift from the unbolted to the bolted Saposhnikovia divaricata. The result of imaging is consistent with the conclusion of pharmacopoeia that the bolted Saposhnikovia divaricata is not used medicinally.

Significance

Compared to commercial imaging methods, the LACFI-MSI method developed is ultra-sensitive, has a greater sensitivity in the analysis of less polar compounds. Spatial distribution analysis of secondary metabolites that previously difficult/unable to detect in bolted and unbolted Saposhnikovia divaricata is realized.

{"title":"Spatial distribution analysis of secondary metabolites in bolted and unbolted Saposhnikovia divaricata by atmospheric pressure laser ablation carbon fiber ionization mass spectrometry imaging","authors":"Na Li , Xialian Cui , Yingjie Lu , Fang Zhang , Su Guo , Yue Su , Yinlong Guo","doi":"10.1016/j.aca.2025.344096","DOIUrl":"10.1016/j.aca.2025.344096","url":null,"abstract":"<div><h3>Background</h3><div>Bolting severely affects the medicinal value and yield of <em>Saposhnikovia divaricata</em>. Currently, spatial distribution of secondary metabolites in bolted and unbolted <em>Saposhnikovia divaricata</em> remains unknown. The commercial Mass spectrometry imaging (MSI) platforms has high sensitivity to high-polar compounds, but suppresses signals of less polar compounds, generating a gap of understanding how spatial distributed of such metabolites that is less prone to ionize.</div></div><div><h3>Results</h3><div>This study developed a highly sensitive Laser Ablation Carbon Fiber Ionization (LACFI) MSI method under atmospheric pressure to achieve the spatial distribution analysis of secondary metabolites in <em>Saposhnikovia divaricata</em>, including low-polar compounds which is difficult to be analyzed in other MSI methods. The laser efficiently desorbs compounds from <em>Saposhnikovia divaricata</em> tissue, and the desorbed compounds are rapidly ionized by a carbon fiber ion source under high pressure. The desorption and ionization are performed in two separate steps, reducing the matrix effect and enhancing the ionization efficiency of compounds, which increase sensitivity. The carbon fiber has good compatibility with polar and low-polar compounds, which increases the number of detectable metabolites. The spatial distribution of secondary metabolites undergoes a shift from the unbolted to the bolted <em>Saposhnikovia divaricata</em>. The result of imaging is consistent with the conclusion of pharmacopoeia that the bolted <em>Saposhnikovia divaricata</em> is not used medicinally.</div></div><div><h3>Significance</h3><div>Compared to commercial imaging methods, the LACFI-MSI method developed is ultra-sensitive, has a greater sensitivity in the analysis of less polar compounds. Spatial distribution analysis of secondary metabolites that previously difficult/unable to detect in bolted and unbolted <em>Saposhnikovia divaricata</em> is realized.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344096"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A minimally instrumented method for the detection of rifampicin resistance-causing mutations in Mycobacterium tuberculosis utilizing lateral flow readout

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344090

Ayushi Chauhan , S. SivaKumar , Bhushan J. Toley

Background

Genotypic methods for detecting antimicrobial resistance in Mycobacterium tuberculosis (M.tb) typically require expensive instrumentation, limiting their accessibility in peripheral and resource-limited settings. Rifampicin resistance is a key marker of multidrug-resistant tuberculosis (MDR-TB) and is primarily caused by mutations in the rpoB gene. Rapid, cost-effective, and minimally instrumented methods for detecting these mutations are essential for improving tuberculosis diagnostics, particularly in low-resource environments. This study addresses the need for a simple, sensitive, and specific assay to detect the four most common rifampicin resistance-associated mutations without relying on complex laboratory infrastructure.

Results

We developed a minimally instrumented method to detect the four most prevalent mutations causing rifampicin resistance in M.tb—S531L, H526Y, H526D, and D516V. The method is based on the oligonucleotide ligation assay (OLA), coupled with lateral flow readout. The method successfully detected wild-type and mutant DNA at limits of 10 and 100 gene copies per reaction, respectively. It exhibited high sensitivity in heterozygous samples, detecting as low as 3 % mutant DNA for all four mutations. Validation with genomic DNA extracted from 29 M.tb isolates from the ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India, demonstrated a sensitivity and specificity of 100 % for M.tb detection and 90.90 % and 100 %, respectively, for rifampicin resistance detection.

Significance

This method provides a cost-effective and minimally instrumented alternative to conventional genotypic resistance detection methods. Its high sensitivity and specificity, combined with its ease of adaptation to other resistance-causing mutations, make it a promising tool for tuberculosis diagnostics in resource-limited settings. By reducing reliance on expensive laboratory infrastructure, this approach could facilitate more accessible and rapid detection of drug-resistant M.tb, improving global TB control efforts.

{"title":"A minimally instrumented method for the detection of rifampicin resistance-causing mutations in Mycobacterium tuberculosis utilizing lateral flow readout","authors":"Ayushi Chauhan , S. SivaKumar , Bhushan J. Toley","doi":"10.1016/j.aca.2025.344090","DOIUrl":"10.1016/j.aca.2025.344090","url":null,"abstract":"<div><h3>Background</h3><div>Genotypic methods for detecting antimicrobial resistance in <em>Mycobacterium tuberculosis (M.tb)</em> typically require expensive instrumentation, limiting their accessibility in peripheral and resource-limited settings. Rifampicin resistance is a key marker of multidrug-resistant tuberculosis (MDR-TB) and is primarily caused by mutations in the <em>rpoB</em> gene. Rapid, cost-effective, and minimally instrumented methods for detecting these mutations are essential for improving tuberculosis diagnostics, particularly in low-resource environments. This study addresses the need for a simple, sensitive, and specific assay to detect the four most common rifampicin resistance-associated mutations without relying on complex laboratory infrastructure.</div></div><div><h3>Results</h3><div>We developed a minimally instrumented method to detect the four most prevalent mutations causing rifampicin resistance in <em>M.tb</em>—S531L, H526Y, H526D, and D516V. The method is based on the oligonucleotide ligation assay (OLA), coupled with lateral flow readout. The method successfully detected wild-type and mutant DNA at limits of 10 and 100 gene copies per reaction, respectively. It exhibited high sensitivity in heterozygous samples, detecting as low as 3 % mutant DNA for all four mutations. Validation with genomic DNA extracted from 29 <em>M.tb</em> isolates from the ICMR-National Institute for Research in Tuberculosis (NIRT), Chennai, India, demonstrated a sensitivity and specificity of 100 % for <em>M.tb</em> detection and 90.90 % and 100 %, respectively, for rifampicin resistance detection.</div></div><div><h3>Significance</h3><div>This method provides a cost-effective and minimally instrumented alternative to conventional genotypic resistance detection methods. Its high sensitivity and specificity, combined with its ease of adaptation to other resistance-causing mutations, make it a promising tool for tuberculosis diagnostics in resource-limited settings. By reducing reliance on expensive laboratory infrastructure, this approach could facilitate more accessible and rapid detection of drug-resistant <em>M.tb,</em> improving global TB control efforts.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344090"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A novel chemiresistive biosensor utilizing green-synthesized AgNPs and MWCNT-ZnO nanofibers for rapid detection of tuberculosis Lipoarabinomannan (LAM) antigen

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-19 DOI: 10.1016/j.aca.2025.344092

Dinesh R. Rotake , Jitendra B. Zalke , Shubham C. Anjankar , Shiv Govind Singh

Background

Tuberculosis (TB) poses a major global health threat, especially in low- and middle-income countries with limited diagnostic infrastructure. Early and accurate detection is essential to control its spread and improve outcomes, but conventional methods like sputum microscopy and culture are slow, resource-intensive, and lack sensitivity for early or extrapulmonary cases. To address this, a cost-effective, disposable, paper-based interdigitated electrode (IDE) biosensor was developed, functionalized with green-synthesized silver nanoparticles (GSSNPs) and Multi-walled Carbon Nanotube - Zinc Oxide (MWCNT-ZnO) composite nanofibers. This innovative sensor combines affordability, portability, and high sensitivity, offering a practical and scalable solution for rapid TB diagnostics in resource-constrained settings.

Results

The developed paper-based interdigitated electrode (IDE) sensor demonstrates highly promising results for the early and accurate detection of tuberculosis (TB) antigens. The sensor achieved an exceptional lower limit of detection (LOD) of 25.79 fg/mL, enabling the detection of trace amounts of TB antigens. Furthermore, it exhibited a broad linear detection range from 10 pg/mL to 6 ng/mL, making it suitable for various clinical sample concentrations. This remarkable sensitivity and detection range highlight the unique capabilities of the functionalized MWCNT-ZnO composite nanofibers (NFs) and GSSNPs utilized in its design. The sensor's performance evaluation revealed high sensitivity, selectivity, and reproducibility, with minimal interference from non-specific interactions. Its disposable, scalable, and environmentally friendly design further enhances its suitability for point-of-care (PoC) applications in resource-limited settings, offering a rapid, cost-effective, and reliable diagnostic tool for managing TB, particularly in underserved regions.

Significance

This study concludes that the developed paper-based IDE sensor offers a highly sensitive, selective, and cost-effective solution for the early detection of TB antigens, with an impressive LOD of 25.79 fg/mL and a broad detection range. Its simple fabrication, disposable design, and environmentally friendly paper substrate make it ideal for point-of-care applications in resource-limited settings. This innovation is significant as it addresses critical diagnostic gaps, enabling early diagnosis and improved TB management, particularly in underserved regions where traditional methods fall short.

{"title":"A novel chemiresistive biosensor utilizing green-synthesized AgNPs and MWCNT-ZnO nanofibers for rapid detection of tuberculosis Lipoarabinomannan (LAM) antigen","authors":"Dinesh R. Rotake , Jitendra B. Zalke , Shubham C. Anjankar , Shiv Govind Singh","doi":"10.1016/j.aca.2025.344092","DOIUrl":"10.1016/j.aca.2025.344092","url":null,"abstract":"<div><h3>Background</h3><div>Tuberculosis (TB) poses a major global health threat, especially in low- and middle-income countries with limited diagnostic infrastructure. Early and accurate detection is essential to control its spread and improve outcomes, but conventional methods like sputum microscopy and culture are slow, resource-intensive, and lack sensitivity for early or extrapulmonary cases. To address this, a cost-effective, disposable, paper-based interdigitated electrode (IDE) biosensor was developed, functionalized with green-synthesized silver nanoparticles (GSSNPs) and Multi-walled Carbon Nanotube - Zinc Oxide (MWCNT-ZnO) composite nanofibers. This innovative sensor combines affordability, portability, and high sensitivity, offering a practical and scalable solution for rapid TB diagnostics in resource-constrained settings.</div></div><div><h3>Results</h3><div>The developed paper-based interdigitated electrode (IDE) sensor demonstrates highly promising results for the early and accurate detection of tuberculosis (TB) antigens. The sensor achieved an exceptional lower limit of detection (LOD) of 25.79 fg/mL, enabling the detection of trace amounts of TB antigens. Furthermore, it exhibited a broad linear detection range from 10 pg/mL to 6 ng/mL, making it suitable for various clinical sample concentrations. This remarkable sensitivity and detection range highlight the unique capabilities of the functionalized MWCNT-ZnO composite nanofibers (NFs) and GSSNPs utilized in its design. The sensor's performance evaluation revealed high sensitivity, selectivity, and reproducibility, with minimal interference from non-specific interactions. Its disposable, scalable, and environmentally friendly design further enhances its suitability for point-of-care (PoC) applications in resource-limited settings, offering a rapid, cost-effective, and reliable diagnostic tool for managing TB, particularly in underserved regions.</div></div><div><h3>Significance</h3><div>This study concludes that the developed paper-based IDE sensor offers a highly sensitive, selective, and cost-effective solution for the early detection of TB antigens, with an impressive LOD of 25.79 fg/mL and a broad detection range. Its simple fabrication, disposable design, and environmentally friendly paper substrate make it ideal for point-of-care applications in resource-limited settings. This innovation is significant as it addresses critical diagnostic gaps, enabling early diagnosis and improved TB management, particularly in underserved regions where traditional methods fall short.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344092"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

γ-cyclodextrin metal-organic framework-activated gold nanoclusters with water solubility as multi-enzyme mimics for simultaneous detection of pesticide and cholinesterase activity

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-18 DOI: 10.1016/j.aca.2025.344093

Bing Tan , Qian Wang , Qiaoli Liu , Yimei Wu , Luyao Ban , Yingli Yan , Xiang Li , Guifen Zhu , Jing Fan , Huimin Zhao

Cyclodextrin metal-organic framework (CD-MOF) with environmentally friendly components has attracted enormous attention in the past few decades. However, the fragile aqueous stability has limited its application in aqueous catalysis. In this work, we have devised a novel strategy to cope with the problems by introducing the well-defined gold nanoclusters (AuNCs) onto the cyclodextrin ligand through host-guest chemistry. The combination with AuNCs endowed the fragile CD-MOF with excellent multi-enzyme mimicking catalytic abilities, including peroxidase (POD), oxidase (OXD), catalase (CAT) and glucose oxidase (GOx)-mimetic activities. Furthermore, based on its intrinsic POD-like activities, by constructing the typical enzyme cascade reaction, a colorimetric sensor based on Au₃₈/γ-CD-MOF was developed for the rapid and sensitive of carbaryl and butyrylcholinesterase (BChE) activity, respectively. In addition, combined with the smartphone, a portable paper-based sensor was developed, which could realize the on-site and semiquantitative detection of pesticide residues by identifying the RGB value. This low-cost and easy-operation portable assay shows great potential for online detection of pesticides exposure and monitoring other disease biomarkers.

{"title":"γ-cyclodextrin metal-organic framework-activated gold nanoclusters with water solubility as multi-enzyme mimics for simultaneous detection of pesticide and cholinesterase activity","authors":"Bing Tan , Qian Wang , Qiaoli Liu , Yimei Wu , Luyao Ban , Yingli Yan , Xiang Li , Guifen Zhu , Jing Fan , Huimin Zhao","doi":"10.1016/j.aca.2025.344093","DOIUrl":"10.1016/j.aca.2025.344093","url":null,"abstract":"<div><div>Cyclodextrin metal-organic framework (CD-MOF) with environmentally friendly components has attracted enormous attention in the past few decades. However, the fragile aqueous stability has limited its application in aqueous catalysis. In this work, we have devised a novel strategy to cope with the problems by introducing the well-defined gold nanoclusters (AuNCs) onto the cyclodextrin ligand through host-guest chemistry. The combination with AuNCs endowed the fragile CD-MOF with excellent multi-enzyme mimicking catalytic abilities, including peroxidase (POD), oxidase (OXD), catalase (CAT) and glucose oxidase (GOx)-mimetic activities. Furthermore, based on its intrinsic POD-like activities, by constructing the typical enzyme cascade reaction, a colorimetric sensor based on Au<sub>38</sub>/γ-CD-MOF was developed for the rapid and sensitive of carbaryl and butyrylcholinesterase (BChE) activity, respectively. In addition, combined with the smartphone, a portable paper-based sensor was developed, which could realize the on-site and semiquantitative detection of pesticide residues by identifying the RGB value. This low-cost and easy-operation portable assay shows great potential for online detection of pesticides exposure and monitoring other disease biomarkers.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344093"},"PeriodicalIF":5.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rapid filamentous fungi gene knockout identification through high-throughput droplet microfluidics

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-18 DOI: 10.1016/j.aca.2025.344094

Yuwen Li , Jing Dai , Huan Zhang , Han Zhang , Adrian Guzman , Song-I Han , Won Bo Shim , Arum Han

Fungi are a diverse group of eukaryotic organisms, with over 1.5 million species inhabiting ecosystems worldwide. Many fungi grow as filaments (hyphae) and play critical ecological roles, both beneficial and harmful. Understanding their functions often requires generating knockout mutants and performing comparative analyses with wild-type strains. However, traditional methods for screening knockout mutants are labor-intensive, time-consuming, and limit the rapid identification of successful transformants. Here, we present a high-throughput droplet microfluidics platform capable of screening and sorting fungal transformants at single-cell resolution, significantly improving efficiency compared to conventional methods. The workflow involves encapsulating individual fungal transformants in pico-liter-volume water-in-oil emulsion droplets, culturing them in the presence of antibiotics, and identifying and sorting droplets containing transformants that exhibit hyphal growth. Transformants that grow in the presence of antibiotics are flagged as potential knockouts and then sorted out for confirmation through sequencing. This approach offers several advantages, including a 3-fold reduction in time for Fusarium graminearum protoplast growth until they can be distinguished from those exhibiting no growth, a screening throughput of up to 28,800 transformant-containing droplets per hour, and single-spore phenotyping to minimize post-processing requirements. Using this system, we successfully screened 24,000 F. graminearum transformants containing droplets, identified five potential transformants that exhibit growth on agar plates, of which two were confirmed via sequencing as true knockouts. These results demonstrate the utility of this droplet microfluidics-based platform as a powerful tool for accelerating fungal functional genomics and advancing our understanding of the ecological roles of fungi.

{"title":"Rapid filamentous fungi gene knockout identification through high-throughput droplet microfluidics","authors":"Yuwen Li , Jing Dai , Huan Zhang , Han Zhang , Adrian Guzman , Song-I Han , Won Bo Shim , Arum Han","doi":"10.1016/j.aca.2025.344094","DOIUrl":"10.1016/j.aca.2025.344094","url":null,"abstract":"<div><div>Fungi are a diverse group of eukaryotic organisms, with over 1.5 million species inhabiting ecosystems worldwide. Many fungi grow as filaments (hyphae) and play critical ecological roles, both beneficial and harmful. Understanding their functions often requires generating knockout mutants and performing comparative analyses with wild-type strains. However, traditional methods for screening knockout mutants are labor-intensive, time-consuming, and limit the rapid identification of successful transformants. Here, we present a high-throughput droplet microfluidics platform capable of screening and sorting fungal transformants at single-cell resolution, significantly improving efficiency compared to conventional methods. The workflow involves encapsulating individual fungal transformants in pico-liter-volume water-in-oil emulsion droplets, culturing them in the presence of antibiotics, and identifying and sorting droplets containing transformants that exhibit hyphal growth. Transformants that grow in the presence of antibiotics are flagged as potential knockouts and then sorted out for confirmation through sequencing. This approach offers several advantages, including a 3-fold reduction in time for <em>Fusarium graminearum</em> protoplast growth until they can be distinguished from those exhibiting no growth, a screening throughput of up to 28,800 transformant-containing droplets per hour, and single-spore phenotyping to minimize post-processing requirements. Using this system, we successfully screened 24,000 <em>F. graminearum</em> transformants containing droplets, identified five potential transformants that exhibit growth on agar plates, of which two were confirmed via sequencing as true knockouts. These results demonstrate the utility of this droplet microfluidics-based platform as a powerful tool for accelerating fungal functional genomics and advancing our understanding of the ecological roles of fungi.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344094"},"PeriodicalIF":5.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A review of point-of-care (POC) and lab-on-chip (LOC) approaches in molecularly imprinted polymer-based electrochemical sensors for biomedical applications

IF 5.7 2区化学 Q1 CHEMISTRY, ANALYTICAL

Analytica Chimica Acta

Pub Date : 2025-04-17 DOI: 10.1016/j.aca.2025.344080

Ahmet Cetinkaya , S. Irem Kaya , Sibel A. Ozkan

Background

In terms of analytical applications, researchers aim to design and develop sensitive, selective, and effective sensors that can be used for diagnostic purposes and disease monitoring. Point-of-care (POC) and lab-on-a-chip (LOC) systems stand out as transformative systems that meet expectations and achieve goals from both perspectives. POC devices produce reliable results quickly, facilitating patient-friendly diagnostics. LOC technology, a combination of biosensors, electronics, optics, and microfluidics, directly reflects the progress in downsizing analytical techniques.

Results

Electrochemical sensors have a lot of potential for use in POC and LOC systems because of their high sensitivity, accuracy, specificity, low detection limits, downsizing possibilities, affordability, and ease of use. Because of their enhanced chemical and physical stability and their chemically modifiable micro- and nanoscale characteristics, molecularly imprinted polymers (MIPs) are particularly interesting for use as recognition components in POC and LOC applications. MIP-based sensors have great promise in being integrated with POC and LOC devices for application in biomedical analysis.

Significance

This review study discusses thoroughly how MIP-based electrochemical sensors can support the expanding field of POC/LOC diagnostics through these cutting-edge technologies. The novelty of this review study is that it specifically addresses the integration of electrochemical MIP sensors into both POC and LOC systems in terms of biomedical applications. It focuses only on the potential of MIP-based electrochemical sensors and brings together studies integrated into POC and LOC platforms.

背景在分析应用方面，研究人员致力于设计和开发可用于诊断和疾病监测的灵敏度高、选择性强且有效的传感器。护理点（POC）和片上实验室（LOC）系统是具有变革意义的系统，能满足人们的期望，实现两个方面的目标。POC 设备能快速得出可靠的结果，方便患者进行诊断。LOC 技术是生物传感器、电子学、光学和微流控技术的结合，直接反映了分析技术小型化方面的进展。分子印迹聚合物 (MIP) 具有更强的化学和物理稳定性，以及可进行化学修饰的微米和纳米级特性，因此特别适合用作 POC 和 LOC 应用中的识别元件。本综述研究深入探讨了基于 MIP 的电化学传感器如何通过这些尖端技术支持不断扩大的 POC/LOC 诊断领域。本综述研究的新颖之处在于，它专门讨论了在生物医学应用方面将电化学 MIP 传感器集成到 POC 和 LOC 系统中的问题。它只关注基于 MIP 的电化学传感器的潜力，并汇集了集成到 POC 和 LOC 平台的研究。

{"title":"A review of point-of-care (POC) and lab-on-chip (LOC) approaches in molecularly imprinted polymer-based electrochemical sensors for biomedical applications","authors":"Ahmet Cetinkaya , S. Irem Kaya , Sibel A. Ozkan","doi":"10.1016/j.aca.2025.344080","DOIUrl":"10.1016/j.aca.2025.344080","url":null,"abstract":"<div><h3>Background</h3><div>In terms of analytical applications, researchers aim to design and develop sensitive, selective, and effective sensors that can be used for diagnostic purposes and disease monitoring. Point-of-care (POC) and lab-on-a-chip (LOC) systems stand out as transformative systems that meet expectations and achieve goals from both perspectives. POC devices produce reliable results quickly, facilitating patient-friendly diagnostics. LOC technology, a combination of biosensors, electronics, optics, and microfluidics, directly reflects the progress in downsizing analytical techniques.</div></div><div><h3>Results</h3><div>Electrochemical sensors have a lot of potential for use in POC and LOC systems because of their high sensitivity, accuracy, specificity, low detection limits, downsizing possibilities, affordability, and ease of use. Because of their enhanced chemical and physical stability and their chemically modifiable micro- and nanoscale characteristics, molecularly imprinted polymers (MIPs) are particularly interesting for use as recognition components in POC and LOC applications. MIP-based sensors have great promise in being integrated with POC and LOC devices for application in biomedical analysis.</div></div><div><h3>Significance</h3><div>This review study discusses thoroughly how MIP-based electrochemical sensors can support the expanding field of POC/LOC diagnostics through these cutting-edge technologies. The novelty of this review study is that it specifically addresses the integration of electrochemical MIP sensors into both POC and LOC systems in terms of biomedical applications. It focuses only on the potential of MIP-based electrochemical sensors and brings together studies integrated into POC and LOC platforms.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1357 ","pages":"Article 344080"},"PeriodicalIF":5.7,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143846993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0