Cyclic organochlorine chemicals (COCs), including dieldrin, endrin, endosulfan, aldrin, heptachlor, chlordane, and toxaphene, persist globally as carcinogenic and neurotoxic persistent organic pollutants, posing bioaccumulation risks. In this study, we designed two haptens based on the common hexachlorocyclopentadiene and norbornane structural scaffolds shared by these seven COCs. The design rationale was evaluated using computational chemistry assistance and validated through animal immunization, followed by immunological analysis data. Based on the predicted hapten H1, a broad-spectrum monoclonal antibody (2A11) was prepared with a sensitivity as low as 14.91 ng/mL. Through the molecular recognition mechanism, the key amino acid residues, HIS-31 and TYR-33, responsible for the broad-spectrum binding and sensitivity to COCs were elucidated. Subsequently, a rapid and broad-spectrum colloidal gold immunochromatographic assay (GICA) was developed. The visual detection limits for the seven COCs were determined to be 10–100 ng/mL in water and 50–500 ng/g in both fish and soil, respectively. Furthermore, results from the analysis of unknown samples showed a good agreement between GICA and gas chromatography-tandem mass spectrometry. The computer-aided chemistry-based hapten prediction strategy effectively guided the preparation of antibodies for broad-spectrum recognition of COCs, enabling their rapid screening and detection.
{"title":"Molecular Recognition-Based Detection: Antibody Dipsticks for Cyclic Organochlorine Chemicals","authors":"Jinyan Li,Lingling Guo,Aihua Qu,Chuanlai Xu,Hua Kuang,Xinxin Xu","doi":"10.1021/acs.analchem.5c06442","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c06442","url":null,"abstract":"Cyclic organochlorine chemicals (COCs), including dieldrin, endrin, endosulfan, aldrin, heptachlor, chlordane, and toxaphene, persist globally as carcinogenic and neurotoxic persistent organic pollutants, posing bioaccumulation risks. In this study, we designed two haptens based on the common hexachlorocyclopentadiene and norbornane structural scaffolds shared by these seven COCs. The design rationale was evaluated using computational chemistry assistance and validated through animal immunization, followed by immunological analysis data. Based on the predicted hapten H1, a broad-spectrum monoclonal antibody (2A11) was prepared with a sensitivity as low as 14.91 ng/mL. Through the molecular recognition mechanism, the key amino acid residues, HIS-31 and TYR-33, responsible for the broad-spectrum binding and sensitivity to COCs were elucidated. Subsequently, a rapid and broad-spectrum colloidal gold immunochromatographic assay (GICA) was developed. The visual detection limits for the seven COCs were determined to be 10–100 ng/mL in water and 50–500 ng/g in both fish and soil, respectively. Furthermore, results from the analysis of unknown samples showed a good agreement between GICA and gas chromatography-tandem mass spectrometry. The computer-aided chemistry-based hapten prediction strategy effectively guided the preparation of antibodies for broad-spectrum recognition of COCs, enabling their rapid screening and detection.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"17 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-04DOI: 10.1021/acs.analchem.5c05489
Willmann Antonio Jiménez Morales,María del Pilar Cañizares-Macías
An innovative method, termed FRAP/ABTS-SIA, was developed to simultaneously integrate the FRAP and ABTS antioxidant assays within a single sequential injection analysis (SIA) system with spectrophotometric detection. Leveraging the kinetic differences between the assays and controlling the dispersion, a compact aspiration sequence (antioxidant–FRAP–ABTS–antioxidant-water) was optimized using a central composite design, defining a flow rate of 40 μL s–1 and aspiration volumes of 43, 38, 38, 43, and 100 μL, respectively. The system incorporated a helical reaction coil positioned before the detector, allowing the antioxidant–FRAP bolus to react while the ABTS–antioxidant–water sequence was aspirated into the holding coil. This configuration enhanced the FRAP signal and enabled clear separation of both analytical responses. Compared to conventional batch protocols, this strategy reduced FRAP reagent concentrations by 70% and ABTS•+ radical concentrations by 50%. The method delivers responses within a 2 min run, achieving a throughput of ∼30 samples h–1. Linearity was confirmed for both assays over the range 10–120 μmol L–1 Trolox, with detection limits of 0.031 μmol L–1 (FRAP) and 0.0047 μmol L–1 (ABTS). Intralaboratory precision was below 2% RSD, and recoveries ranged from 97.3 to 106.2% (FRAP) and 92.8 to 105.4% (ABTS). The method was successfully applied to complex food matrices─including coffees, wines, juices, and spices─showing correlations ≥0.99 with microplate reference assays. High-throughput, reagent savings, metrological robustness, and simplified data processing position FRAP/ABTS-SIA as an efficient and reliable tool for routine antioxidant capacity evaluation in food and biomedical applications.
{"title":"A Breakthrough SIA-Based Dual Assay for Simultaneous Evaluation of Antioxidant Capacity via ABTS and FRAP Mechanisms","authors":"Willmann Antonio Jiménez\u0000Morales,María del Pilar Cañizares-Macías","doi":"10.1021/acs.analchem.5c05489","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c05489","url":null,"abstract":"An innovative method, termed FRAP/ABTS-SIA, was developed to simultaneously integrate the FRAP and ABTS antioxidant assays within a single sequential injection analysis (SIA) system with spectrophotometric detection. Leveraging the kinetic differences between the assays and controlling the dispersion, a compact aspiration sequence (antioxidant–FRAP–ABTS–antioxidant-water) was optimized using a central composite design, defining a flow rate of 40 μL s–1 and aspiration volumes of 43, 38, 38, 43, and 100 μL, respectively. The system incorporated a helical reaction coil positioned before the detector, allowing the antioxidant–FRAP bolus to react while the ABTS–antioxidant–water sequence was aspirated into the holding coil. This configuration enhanced the FRAP signal and enabled clear separation of both analytical responses. Compared to conventional batch protocols, this strategy reduced FRAP reagent concentrations by 70% and ABTS•+ radical concentrations by 50%. The method delivers responses within a 2 min run, achieving a throughput of ∼30 samples h–1. Linearity was confirmed for both assays over the range 10–120 μmol L–1 Trolox, with detection limits of 0.031 μmol L–1 (FRAP) and 0.0047 μmol L–1 (ABTS). Intralaboratory precision was below 2% RSD, and recoveries ranged from 97.3 to 106.2% (FRAP) and 92.8 to 105.4% (ABTS). The method was successfully applied to complex food matrices─including coffees, wines, juices, and spices─showing correlations ≥0.99 with microplate reference assays. High-throughput, reagent savings, metrological robustness, and simplified data processing position FRAP/ABTS-SIA as an efficient and reliable tool for routine antioxidant capacity evaluation in food and biomedical applications.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"8 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of efficient and stable electrochemiluminescence (ECL) emitters remains a major challenge in practical sensing applications. Although copper nanoclusters (CuNCs) have attracted increasing attention due to their low cost and molecule-like electronic structures, their ECL activity is often limited by disordered aggregation and weak radiative emission. In this study, we report a deprotonation-driven interfacial assembly strategy for CuNCs, leading to a remarkable enhancement in the ECL performance. Using 4,6-diamino-2-mercaptopyrimidine (DAMP) as a multifunctional reductant and capping ligand, disordered aggregates (CuNCsacid) formed under acidic conditions undergo structural evolution in response to pH, transforming into highly ordered nanosheets (CuNCsbase) in mildly alkaline media. This transformation is driven by the deprotonation of amino groups, which strengthens the interligand hydrogen bond networks and promotes π–π stacking, ultimately yielding compact structures enriched in Cu(I) species. The ordered assemblies effectively suppress nonradiative relaxation and lower the onset potential, leading to an ECL enhancement of nearly 3 orders of magnitude compared to that of CuNCsacid. Benefiting from these features, a highly sensitive ECL biosensor for N-acetyl-β-d-glucosaminidase (NAG) detection in human urine was constructed employing CuNCsbase as emitters. The signal is generated by the enzyme catalytic production of p-nitrophenol (PNP), which perturbs the hydrogen-bond-directed assembly of CuNCsbase, causing an activity-dependent decrease in the ECL signal. By establishing a pH-modulated assembly strategy to boost ECL emission, this study opens new avenues for the rational design of high-performance, CuNC-based bioanalytical luminophores.
{"title":"Deprotonation-Driven Assembly of Copper Nanoclusters Boosts Electrochemiluminescence for Sensitive N-Acetyl-β-d-glucosaminidase Biosensing","authors":"Qian Sun,Xue Ge,Xiaotong Li,Mingming Zhang,Guoqiu Wu,Yuanjian Zhang,Yanfei Shen","doi":"10.1021/acs.analchem.5c08008","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c08008","url":null,"abstract":"The development of efficient and stable electrochemiluminescence (ECL) emitters remains a major challenge in practical sensing applications. Although copper nanoclusters (CuNCs) have attracted increasing attention due to their low cost and molecule-like electronic structures, their ECL activity is often limited by disordered aggregation and weak radiative emission. In this study, we report a deprotonation-driven interfacial assembly strategy for CuNCs, leading to a remarkable enhancement in the ECL performance. Using 4,6-diamino-2-mercaptopyrimidine (DAMP) as a multifunctional reductant and capping ligand, disordered aggregates (CuNCsacid) formed under acidic conditions undergo structural evolution in response to pH, transforming into highly ordered nanosheets (CuNCsbase) in mildly alkaline media. This transformation is driven by the deprotonation of amino groups, which strengthens the interligand hydrogen bond networks and promotes π–π stacking, ultimately yielding compact structures enriched in Cu(I) species. The ordered assemblies effectively suppress nonradiative relaxation and lower the onset potential, leading to an ECL enhancement of nearly 3 orders of magnitude compared to that of CuNCsacid. Benefiting from these features, a highly sensitive ECL biosensor for N-acetyl-β-d-glucosaminidase (NAG) detection in human urine was constructed employing CuNCsbase as emitters. The signal is generated by the enzyme catalytic production of p-nitrophenol (PNP), which perturbs the hydrogen-bond-directed assembly of CuNCsbase, causing an activity-dependent decrease in the ECL signal. By establishing a pH-modulated assembly strategy to boost ECL emission, this study opens new avenues for the rational design of high-performance, CuNC-based bioanalytical luminophores.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"59 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1021/acs.analchem.5c07449
Yiran Liu, Gang Li, Jing Zheng, Qing Li, Wei-Min Tong, Weiyi Lai, Hailin Wang
Analytical challenges in detecting sequencing-unknown extrachromosomal circular DNA (eccDNA)─a molecule with critical roles in tumorigenesis and therapeutic potential─primarily arise from interference by long linear genomic and mitochondrial DNA. Here, we for the first time introduce a selective real-time rolling circle amplification (sRT-RCA) method that overcomes this limitation by combining RecBCD and PacI dual-enzyme digestion to remove interfering nucleic acids, thus permitting direct Phi29 polymerase-mediated RT-RCA without the need for conventional physical purification step. This approach achieves unprecedented sensitivity (2 pg, ∼4 × 10–19 mol circular DNA molecules) within a 104-fold higher background of genomic DNA. Furthermore, the established method, utilizing a simplified direct-lysis workflow, is capable of detecting eccDNA from as few as 125 cells. By this approach, we estimated that eccDNA averages 540 copies (8kb plasmid equivalents) in certain cancer cells (K562). Clinically, eccDNA was detected in 3/10 early stage and 6/10 advanced-stage patients. These findings indicate that eccDNA is widespread in cancer patients and demonstrate the potential utility of our method in clinical applications and translational research, thereby bridging a key technical gap and accelerating the translation of eccDNA-based diagnostics and personalized therapy.
{"title":"Ultrasensitive and Rapid Screening of Tumor-Associated Extrachromosomal Circular DNA by Selective Real-Time Rolling Circle Amplification","authors":"Yiran Liu, Gang Li, Jing Zheng, Qing Li, Wei-Min Tong, Weiyi Lai, Hailin Wang","doi":"10.1021/acs.analchem.5c07449","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c07449","url":null,"abstract":"Analytical challenges in detecting sequencing-unknown extrachromosomal circular DNA (eccDNA)─a molecule with critical roles in tumorigenesis and therapeutic potential─primarily arise from interference by long linear genomic and mitochondrial DNA. Here, we for the first time introduce a selective real-time rolling circle amplification (sRT-RCA) method that overcomes this limitation by combining RecBCD and PacI dual-enzyme digestion to remove interfering nucleic acids, thus permitting direct Phi29 polymerase-mediated RT-RCA without the need for conventional physical purification step. This approach achieves unprecedented sensitivity (2 pg, ∼4 × 10<sup>–19</sup> mol circular DNA molecules) within a 10<sup>4</sup>-fold higher background of genomic DNA. Furthermore, the established method, utilizing a simplified direct-lysis workflow, is capable of detecting eccDNA from as few as 125 cells. By this approach, we estimated that eccDNA averages 540 copies (8kb plasmid equivalents) in certain cancer cells (K562). Clinically, eccDNA was detected in 3/10 early stage and 6/10 advanced-stage patients. These findings indicate that eccDNA is widespread in cancer patients and demonstrate the potential utility of our method in clinical applications and translational research, thereby bridging a key technical gap and accelerating the translation of eccDNA-based diagnostics and personalized therapy.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"233 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Foodborne pathogens present significant public health risks, demanding sensitive on-site detection and effective antibacterial strategies. To address this, we synthesized magnetic-gold plasmonic blackbody (MNP@GPB) nanocomposites by coating a gold/polydopamine hybrid layer onto magnetic nanoparticles (MNPs) via in situ redox polymerization. The resulting MNP@GPBs exhibited excellent colloidal stability, broadband absorption, rapid magnetic responsiveness, and efficient photothermal conversion. Leveraging these properties, we engineered multifunctional probes for magnetic enrichment, colorimetric and photothermal signal generation, and antibacterial action in immunochromatographic assays (ICAs) for sensitive detection and simultaneous inactivation of Salmonella typhimurium. The limits of detection for MNP@GPB-ICA in the colorimetric and photothermal formats were 1.4 × 103 and 3.4 × 102 CFU/mL, respectively, representing approximately 8-fold and 32-fold improvements in sensitivity over gold nanoparticle-based-ICA. Notably, near-complete inactivation of residual S. typhimurium on the test line was achieved after near-infrared irradiation, substantially reducing the risk of secondary contamination from discarded strips. MNP@GPBs thus represent a transformative platform unifying diagnostic signaling with antibacterial functionality for food safety monitoring.
{"title":"Magnetic-Gold Plasmonic Blackbodies for Photothermal Immunochromatographic Detection and Inactivation of Salmonella typhimurium","authors":"Yuhao Wu,Qianying Li,Qing Liu,Jiayi Sun,Liu Jiang,Weitao He,Xiaolong Wang,Yuankui Leng,Yonghua Xiong,Xiaolin Huang","doi":"10.1021/acs.analchem.5c07116","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c07116","url":null,"abstract":"Foodborne pathogens present significant public health risks, demanding sensitive on-site detection and effective antibacterial strategies. To address this, we synthesized magnetic-gold plasmonic blackbody (MNP@GPB) nanocomposites by coating a gold/polydopamine hybrid layer onto magnetic nanoparticles (MNPs) via in situ redox polymerization. The resulting MNP@GPBs exhibited excellent colloidal stability, broadband absorption, rapid magnetic responsiveness, and efficient photothermal conversion. Leveraging these properties, we engineered multifunctional probes for magnetic enrichment, colorimetric and photothermal signal generation, and antibacterial action in immunochromatographic assays (ICAs) for sensitive detection and simultaneous inactivation of Salmonella typhimurium. The limits of detection for MNP@GPB-ICA in the colorimetric and photothermal formats were 1.4 × 103 and 3.4 × 102 CFU/mL, respectively, representing approximately 8-fold and 32-fold improvements in sensitivity over gold nanoparticle-based-ICA. Notably, near-complete inactivation of residual S. typhimurium on the test line was achieved after near-infrared irradiation, substantially reducing the risk of secondary contamination from discarded strips. MNP@GPBs thus represent a transformative platform unifying diagnostic signaling with antibacterial functionality for food safety monitoring.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"13 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lateral flow assays (LFAs) are widely used for point-of-care (POC) diagnostics but often suffer from limited sensitivity and specificity compared with laboratory methods. Here, we present a multimodal LFA platform integrating colorimetric, photothermal, and second near-infrared window (NIR-II) fluorescence readouts for enhanced sensitivity and multiplexed detection. Gold nanorods were coupled with bright NIR-II emissive polymer dots to generate plasmon-enhanced fluorescence and efficient photothermal signals within a single probe. As proof-of-concept, carbohydrate antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) were selected as target biomarkers for breast cancer screening and broader cancer indication, respectively. Both thermometric and NIR-II fluorescence modes achieved comparable limits of detection for CA15-3 (0.40 and 0.42 U/mL) with a dynamic range of 0–100 U/mL, while CEA was quantified with a detection limit of 0.096 ng/mL. Multiplexed analysis on a single strip allowed simultaneous detection of CA15-3 and CEA with minimal cross-reactivity, and NIR-II fluorescence from test line 2 was intentionally designed to be invisible to the naked eye to avoid interference with rapid CA15-3 screening. Validation with clinical serum samples demonstrated a strong correlation with standard electrochemiluminescence immunoassays. This portable, low-cost platform demonstrates that NIR-II fluorescence and photothermal readouts can be harmonized for sensitive, selective, and multiplexed POC cancer biomarker detection. This universal and signal-amplifying concept can be further adapted to other targets of interest, offering a promising route toward next-generation LFAs.
{"title":"Sensitivity Enhancement of Multiplex Lateral Flow Immunoassays by NIR-II Fluorescence and Thermal Contrast","authors":"Yi-Chi Luo,Yung-Chun Hsieh,Chun-Yang Huang,Yu-Jun Liu,Hsin-Ting Huang,Yan-Chang Chen,Tsung-Yuan Wang,Chong-You Chen,Yang-Hsiang Chan","doi":"10.1021/acs.analchem.5c06734","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c06734","url":null,"abstract":"Lateral flow assays (LFAs) are widely used for point-of-care (POC) diagnostics but often suffer from limited sensitivity and specificity compared with laboratory methods. Here, we present a multimodal LFA platform integrating colorimetric, photothermal, and second near-infrared window (NIR-II) fluorescence readouts for enhanced sensitivity and multiplexed detection. Gold nanorods were coupled with bright NIR-II emissive polymer dots to generate plasmon-enhanced fluorescence and efficient photothermal signals within a single probe. As proof-of-concept, carbohydrate antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) were selected as target biomarkers for breast cancer screening and broader cancer indication, respectively. Both thermometric and NIR-II fluorescence modes achieved comparable limits of detection for CA15-3 (0.40 and 0.42 U/mL) with a dynamic range of 0–100 U/mL, while CEA was quantified with a detection limit of 0.096 ng/mL. Multiplexed analysis on a single strip allowed simultaneous detection of CA15-3 and CEA with minimal cross-reactivity, and NIR-II fluorescence from test line 2 was intentionally designed to be invisible to the naked eye to avoid interference with rapid CA15-3 screening. Validation with clinical serum samples demonstrated a strong correlation with standard electrochemiluminescence immunoassays. This portable, low-cost platform demonstrates that NIR-II fluorescence and photothermal readouts can be harmonized for sensitive, selective, and multiplexed POC cancer biomarker detection. This universal and signal-amplifying concept can be further adapted to other targets of interest, offering a promising route toward next-generation LFAs.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"1 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1021/acs.analchem.5c06635
Hongyue Hu, Tao Ding, Haodong Li, Nan Zhang, Peng Zheng, Min Ke, Le Liang
Precise control of fluorescence quantum yield at the single-emitter level is pivotal for molecular imaging and ultrasensitive detection, yet most plasmon–fluorophore studies rely on fixed gaps or ensemble averages, leaving autonomous, real-time tuning of an individual emitter via nanometal surface energy transfer largely unexplored. Here, we introduce an autonomous DNA–metallic nanoswitch that continuously modulates a single emitter’s quantum yield by dynamically varying its separation from a gold nanoparticle. Programmable DNA hybridization acts as a molecular lever that shuttles the dye between a subnanometer “off” state (r < 1 nm), where nonradiative energy transfer quenches emission, and a multinanometer “on” state (r > 4 nm), where emission recovers; the resulting reversible oscillations follow the characteristic ∼1/d4 distance dependence. This distance-encoded operation yields robust self-blinking trajectories and time-domain metrics (on/off contrast and dwell times) even under high-background conditions. With built-in blinking, nanometer-scale positioning, and straightforward DNA addressability, the nanoswitch deepens understanding of metal-fluorophore coupling and provides a versatile platform for time-resolved single-molecule readout in imaging and diagnostics.
{"title":"Autonomous DNA Nanoswitch Encodes Quantum-Yield Oscillations for Time-Resolved Single-Molecule Readout","authors":"Hongyue Hu, Tao Ding, Haodong Li, Nan Zhang, Peng Zheng, Min Ke, Le Liang","doi":"10.1021/acs.analchem.5c06635","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c06635","url":null,"abstract":"Precise control of fluorescence quantum yield at the single-emitter level is pivotal for molecular imaging and ultrasensitive detection, yet most plasmon–fluorophore studies rely on fixed gaps or ensemble averages, leaving autonomous, real-time tuning of an individual emitter via nanometal surface energy transfer largely unexplored. Here, we introduce an autonomous DNA–metallic nanoswitch that continuously modulates a single emitter’s quantum yield by dynamically varying its separation from a gold nanoparticle. Programmable DNA hybridization acts as a molecular lever that shuttles the dye between a subnanometer “off” state (<i>r</i> < 1 nm), where nonradiative energy transfer quenches emission, and a multinanometer “on” state (<i>r</i> > 4 nm), where emission recovers; the resulting reversible oscillations follow the characteristic ∼1/d<sup>4</sup> distance dependence. This distance-encoded operation yields robust self-blinking trajectories and time-domain metrics (on/off contrast and dwell times) even under high-background conditions. With built-in blinking, nanometer-scale positioning, and straightforward DNA addressability, the nanoswitch deepens understanding of metal-fluorophore coupling and provides a versatile platform for time-resolved single-molecule readout in imaging and diagnostics.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"87 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1021/acs.analchem.5c07937
Nicolas Molina, Andrei Dolocan, John F. Curry, Gregory J. Rodin, Filippo Mangolini
Secondary Ion Mass Spectrometry (SIMS) is a powerful technique for investigating diffusion at and near material surfaces. It directly measures the intensity of secondary ions ejected upon ion beam bombardment of sample surfaces. In SIMS diffusion studies, three concentration proxies rather than intensities are often employed. Using the classical diffusion equation as the basis, we establish conditions under which each proxy is acceptable for extracting diffusivities. We demonstrate that these conditions depend on the temporal and spatial evolution of the intensity of the reference secondary ion. Further, these conditions may or may not be realized in experiments, regardless of the chemical potential landscape of the matrix. We advocate for reporting raw data as is, i.e., in terms of intensities of ejected ions.
{"title":"A Critical Evaluation of Concentration Proxies in SIMS Diffusion Studies","authors":"Nicolas Molina, Andrei Dolocan, John F. Curry, Gregory J. Rodin, Filippo Mangolini","doi":"10.1021/acs.analchem.5c07937","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c07937","url":null,"abstract":"Secondary Ion Mass Spectrometry (SIMS) is a powerful technique for investigating diffusion at and near material surfaces. It directly measures the intensity of secondary ions ejected upon ion beam bombardment of sample surfaces. In SIMS diffusion studies, three concentration proxies rather than intensities are often employed. Using the classical diffusion equation as the basis, we establish conditions under which each proxy is acceptable for extracting diffusivities. We demonstrate that these conditions depend on the temporal and spatial evolution of the intensity of the reference secondary ion. Further, these conditions may or may not be realized in experiments, regardless of the chemical potential landscape of the matrix. We advocate for reporting raw data as is, <i>i.e</i>., in terms of intensities of ejected ions.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"40 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1021/acs.analchem.5c07588
Wenyan Li,Shuanglin Deng,Zhenrun Li,Peilin Wang,Zihui Liang,Tszyin Poon,Qiang Ma
Metal–organic frameworks (MOFs) have emerged as a promising class of luminescence emitters due to their highly tunable structures and intrinsic luminescent characteristics. In this study, a double-shell hollow Hf-MOF (DSH Hf-MOF) was prepared via a dual-template assembly. The DSH Hf-MOF with highly accessible mesoporous/microporous channels, thick walls, and high crystallinity displayed an excellent luminescence property. On the one hand, the double-shell ordered architecture induced significant spatial confinement effects, effectively retarding reactant diffusion and dilution. On the other hand, the double-shell architecture functioned as a parallel circuit, with each shell acting as an independent resistor. The overall resistance was reduced, which significantly improved the efficiency of electron transport. Furthermore, an Ag nanowires@Cu2–xSe Schottky junction array was prepared to provide a uniform and stable electromagnetic field enhancement. Benefiting from the surface plasmonic coupling effect, the luminescence intensity of DSH Hf-MOF was enhanced 7.05 times. The DSH Hf-MOF-driven electrochemiluminescence (ECL) sensor was used for the detection of miRNA-7 with a range from 0.5 fM to 1 nM and a low detection limit of 0.15 fM. More importantly, this biosensor can effectively distinguish between glioma tumor tissues and adjacent paracancerous tissues, demonstrating clear application value in clinical pathological differentiation.
{"title":"A Double-Shell Hollow Hf-MOF-Driven Electrochemiluminescence Strategy for the Detection of miRNA-7","authors":"Wenyan Li,Shuanglin Deng,Zhenrun Li,Peilin Wang,Zihui Liang,Tszyin Poon,Qiang Ma","doi":"10.1021/acs.analchem.5c07588","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c07588","url":null,"abstract":"Metal–organic frameworks (MOFs) have emerged as a promising class of luminescence emitters due to their highly tunable structures and intrinsic luminescent characteristics. In this study, a double-shell hollow Hf-MOF (DSH Hf-MOF) was prepared via a dual-template assembly. The DSH Hf-MOF with highly accessible mesoporous/microporous channels, thick walls, and high crystallinity displayed an excellent luminescence property. On the one hand, the double-shell ordered architecture induced significant spatial confinement effects, effectively retarding reactant diffusion and dilution. On the other hand, the double-shell architecture functioned as a parallel circuit, with each shell acting as an independent resistor. The overall resistance was reduced, which significantly improved the efficiency of electron transport. Furthermore, an Ag nanowires@Cu2–xSe Schottky junction array was prepared to provide a uniform and stable electromagnetic field enhancement. Benefiting from the surface plasmonic coupling effect, the luminescence intensity of DSH Hf-MOF was enhanced 7.05 times. The DSH Hf-MOF-driven electrochemiluminescence (ECL) sensor was used for the detection of miRNA-7 with a range from 0.5 fM to 1 nM and a low detection limit of 0.15 fM. More importantly, this biosensor can effectively distinguish between glioma tumor tissues and adjacent paracancerous tissues, demonstrating clear application value in clinical pathological differentiation.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"39 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146111060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-03DOI: 10.1021/acs.analchem.5c06118
Xuejiao Li, Mengshi Xia, Kexing Peng, Yang Xiang, Ke Liu, Xiaolong Wang, Tianfeng Luo, Shuang Xu, Hui Huang, Chenghong Li, Zeyu Ren, Yi Liu, Huamin Liu, Zhiyu Ling, Junsong Zheng
Even though a lot of research shows that blood miRNA-155 is a specific, early stage biomarker for sepsis and associated consequences, current detection techniques need to be improved. In this work, we created Ag NCs@C NF nanocomposite luminous materials using carbon nanoflowers (C NFs) as a framework. The Ag NCs@C NF signal is much improved by the addition of l-cysteine (l-Cys), causing the biosensor response to change from “ON” to “super ON.” By modifying the hammerhead ribozyme (HHR) into an artificial allosteric blocking ribozyme (BRmiRNA-155) that specifically binds to miRNA-155, this ribozyme rapidly and repeatedly cleaves locked crRNA in the presence of miRNA-155, enabling non-nucleic acid amplification-based miRNA detection. This amplification-free electrochemiluminescence (ECL) biosensor system detects miRNA-155 within a range of 100 aM–100 nM, with a limit of detection (LOD) of 47.4 aM. Additional tests demonstrating specificity, sensitivity, stability, and reproducibility also yielded excellent performance. This technology opens new avenues for the early diagnosis of sepsis and its complications.
尽管大量研究表明，血液miRNA-155是脓毒症及其相关后果的特异性早期生物标志物，但目前的检测技术需要改进。在这项工作中，我们以碳纳米花（C纳米花）为框架创建了Ag NCs@C NF纳米复合发光材料。加入l-半胱氨酸（l-Cys）大大改善了Ag NCs@C NF信号，使生物传感器反应从“开”变为“超级开”。通过将锤头核酶（HHR）修饰为特异性结合miRNA-155的人工变抗性阻断核酶（BRmiRNA-155），该核酶在miRNA-155存在的情况下快速、重复地切割锁定的crRNA，从而实现基于非核酸扩增的miRNA检测。该无扩增的电化学发光（ECL）生物传感器系统可检测100 aM - 100 nM范围内的miRNA-155，检测限（LOD）为47.4 aM。额外的测试证明了特异性、敏感性、稳定性和可重复性，也产生了优异的性能。这项技术为败血症及其并发症的早期诊断开辟了新的途径。
{"title":"Application of an l-Cysteine-Enhanced Ag NCs@C NF Amplification-Free ECL Biosensor for miRNA","authors":"Xuejiao Li, Mengshi Xia, Kexing Peng, Yang Xiang, Ke Liu, Xiaolong Wang, Tianfeng Luo, Shuang Xu, Hui Huang, Chenghong Li, Zeyu Ren, Yi Liu, Huamin Liu, Zhiyu Ling, Junsong Zheng","doi":"10.1021/acs.analchem.5c06118","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c06118","url":null,"abstract":"Even though a lot of research shows that blood miRNA-155 is a specific, early stage biomarker for sepsis and associated consequences, current detection techniques need to be improved. In this work, we created Ag NCs@C NF nanocomposite luminous materials using carbon nanoflowers (C NFs) as a framework. The Ag NCs@C NF signal is much improved by the addition of <span>l</span>-cysteine (<span>l</span>-Cys), causing the biosensor response to change from “ON” to “super ON.” By modifying the hammerhead ribozyme (HHR) into an artificial allosteric blocking ribozyme (BR<sub>miRNA-155</sub>) that specifically binds to miRNA-155, this ribozyme rapidly and repeatedly cleaves locked crRNA in the presence of miRNA-155, enabling non-nucleic acid amplification-based miRNA detection. This amplification-free electrochemiluminescence (ECL) biosensor system detects miRNA-155 within a range of 100 aM–100 nM, with a limit of detection (LOD) of 47.4 aM. Additional tests demonstrating specificity, sensitivity, stability, and reproducibility also yielded excellent performance. This technology opens new avenues for the early diagnosis of sepsis and its complications.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"67 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146101939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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