Multimeric proteins normally perform different biological functions from their monomer components. Thus, precise recognition and quantitative detection of multimeric proteins can benefit a better understanding of complex biological processes and their roles in disease diagnosis and treatment. The challenge herein is to distinguish the multimeric proteins containing identical monomer components and recognize all the monomers in a multimeric protein on spatial scales. This situation is likely to become more significant for homomultimeric proteins. In this study, a DNA polyhedron mass-tagged probe set strategy was developed for the programmed detection of multimeric proteins in living cells. The probe set comprised recognition and displacement probes, a DNA polyhedron probe, and a mass-tagged probe. After point-to-point recognition of each monomer in the target protein complex by recognition and displacement probes, the DNA polyhedron probe could integrate the information on all the protein monomers by carrying out induced self-assembly via a cascaded toehold-mediated strand-displacement (TMSD) reaction. Afterward, the mass-tagged probe collected the integrated information, and the mass tag in the probe was released by ultraviolet (UV) irradiation and detected by mass spectrometry (MS). Using the tmTNF-α homotrimer as an example, its expression levels in different breast cancer cell lines were ultimately determined using this probe set containing a DNA tetrahedron probe. This study is among the first to quantitatively detect multimeric proteins in living cells. Using a similar strategy, more DNA polyhedron mass-tagged probe sets can be developed for the detection of higher-order multimeric proteins.
{"title":"DNA Tetrahedron Mass-Tagged Probe Set for the Programmed Detection of Protein Trimers by Point-to-Point Recognition and Induced Self-Assembly in Living Cells","authors":"Jiapu Li, Xiaoxu Li, Yunjing Wang, Jianhua Zhu, Yun Chen","doi":"10.1021/acs.analchem.4c05947","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c05947","url":null,"abstract":"Multimeric proteins normally perform different biological functions from their monomer components. Thus, precise recognition and quantitative detection of multimeric proteins can benefit a better understanding of complex biological processes and their roles in disease diagnosis and treatment. The challenge herein is to distinguish the multimeric proteins containing identical monomer components and recognize all the monomers in a multimeric protein on spatial scales. This situation is likely to become more significant for homomultimeric proteins. In this study, a DNA polyhedron mass-tagged probe set strategy was developed for the programmed detection of multimeric proteins in living cells. The probe set comprised recognition and displacement probes, a DNA polyhedron probe, and a mass-tagged probe. After point-to-point recognition of each monomer in the target protein complex by recognition and displacement probes, the DNA polyhedron probe could integrate the information on all the protein monomers by carrying out induced self-assembly via a cascaded toehold-mediated strand-displacement (TMSD) reaction. Afterward, the mass-tagged probe collected the integrated information, and the mass tag in the probe was released by ultraviolet (UV) irradiation and detected by mass spectrometry (MS). Using the tmTNF-α homotrimer as an example, its expression levels in different breast cancer cell lines were ultimately determined using this probe set containing a DNA tetrahedron probe. This study is among the first to quantitatively detect multimeric proteins in living cells. Using a similar strategy, more DNA polyhedron mass-tagged probe sets can be developed for the detection of higher-order multimeric proteins.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"30 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470896","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 : 2025-02-22DOI: 10.1021/acs.analchem.4c06937
Naeem Iqbal, Amy Wolstenholme-Hogg, James R. Gompels, Victor Chechik
Self-assembled organosilane monolayers on silica surfaces find many applications; however, their structural characterization is challenging. We found that organic molecules in these monolayers can be dissociated from the surface by cleaving C–Si bonds under mild conditions of Fleming-Tamao oxidation. Once removed from the surface, the monolayer molecules could be isolated, purified, and analyzed in solution using conventional analytical techniques including NMR and GC-MS. This method enables efficient cleavage of different organic molecules attached to silica supports (e.g., in mixed monolayers) and is tolerant to a wide range of functional groups. Organic monolayers can be dissociated from a range of silica substrates, including silica nanoparticles, silica gel, flat glass slides, and related inorganic oxides, such as alumina or titania.
{"title":"Quantitative Characterization of Organosilane Monolayers by Oxidative Dissociation of Monolayer Molecules","authors":"Naeem Iqbal, Amy Wolstenholme-Hogg, James R. Gompels, Victor Chechik","doi":"10.1021/acs.analchem.4c06937","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06937","url":null,"abstract":"Self-assembled organosilane monolayers on silica surfaces find many applications; however, their structural characterization is challenging. We found that organic molecules in these monolayers can be dissociated from the surface by cleaving C–Si bonds under mild conditions of Fleming-Tamao oxidation. Once removed from the surface, the monolayer molecules could be isolated, purified, and analyzed in solution using conventional analytical techniques including NMR and GC-MS. This method enables efficient cleavage of different organic molecules attached to silica supports (e.g., in mixed monolayers) and is tolerant to a wide range of functional groups. Organic monolayers can be dissociated from a range of silica substrates, including silica nanoparticles, silica gel, flat glass slides, and related inorganic oxides, such as alumina or titania.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"21 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470899","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 : 2025-02-22DOI: 10.1021/acs.analchem.4c05537
Mingrui Chen, Guan Liu, Li Wang, Amin Zhang, Ziyang Yang, Xia Li, Zhong Zhang, Song Gu, Daxiang Cui, Hossam Haick, Ning Tang
Interleukin-6 (IL-6) plays a pivotal role in the inflammatory response of diabetic wounds, providing critical insights for clinicians in the development of personalized treatment strategies. However, the low concentration of IL-6 in biological samples, coupled with the presence of numerous interfering substances, poses a significant challenge for its rapid and accurate detection. Herein, we present a dual-mode microfluidic platform integrating electrochemical (EC) and surface-enhanced Raman spectroscopy (SERS) to achieve the timely and highly reliable quantification of IL-6. Efficient binding between IL-6 and antibody-conjugated SERS nanoprobes is obtained through a square-wave micromixer with nonleaky obstacles, forming sandwich immunocomplexes with IL-6 capture antibodies on the working electrode in the detection area, enabling acquisition of both EC and SERS signals. This microfluidic platform demonstrates excellent selectivity and sensitivity, with detection limits of 0.085 and 0.047 pg/mL for EC and SERS modes, respectively. Importantly, by incorporating a neural network (NN) with a self-attention (SA) mechanism to evaluate the relative weights of data from both modes, the platform achieves a quantitative accuracy of up to 99.8% across a range of 0.05–1000 pg/mL, demonstrating significant performance at low concentrations. Moreover, the NN-enhanced dual-mode microfluidic platform effectively detects IL-6 in diabetic wound exudates with results that align closely with clinical data. This integrated dual-mode microfluidic platform offers promising potential for the rapid and accurate detection of cytokines.
{"title":"Neural Network–Enhanced Electrochemical/SERS Dual-Mode Microfluidic Platform for Accurate Detection of Interleukin-6 in Diabetic Wound Exudates","authors":"Mingrui Chen, Guan Liu, Li Wang, Amin Zhang, Ziyang Yang, Xia Li, Zhong Zhang, Song Gu, Daxiang Cui, Hossam Haick, Ning Tang","doi":"10.1021/acs.analchem.4c05537","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c05537","url":null,"abstract":"Interleukin-6 (IL-6) plays a pivotal role in the inflammatory response of diabetic wounds, providing critical insights for clinicians in the development of personalized treatment strategies. However, the low concentration of IL-6 in biological samples, coupled with the presence of numerous interfering substances, poses a significant challenge for its rapid and accurate detection. Herein, we present a dual-mode microfluidic platform integrating electrochemical (EC) and surface-enhanced Raman spectroscopy (SERS) to achieve the timely and highly reliable quantification of IL-6. Efficient binding between IL-6 and antibody-conjugated SERS nanoprobes is obtained through a square-wave micromixer with nonleaky obstacles, forming sandwich immunocomplexes with IL-6 capture antibodies on the working electrode in the detection area, enabling acquisition of both EC and SERS signals. This microfluidic platform demonstrates excellent selectivity and sensitivity, with detection limits of 0.085 and 0.047 pg/mL for EC and SERS modes, respectively. Importantly, by incorporating a neural network (NN) with a self-attention (SA) mechanism to evaluate the relative weights of data from both modes, the platform achieves a quantitative accuracy of up to 99.8% across a range of 0.05–1000 pg/mL, demonstrating significant performance at low concentrations. Moreover, the NN-enhanced dual-mode microfluidic platform effectively detects IL-6 in diabetic wound exudates with results that align closely with clinical data. This integrated dual-mode microfluidic platform offers promising potential for the rapid and accurate detection of cytokines.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"52 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470894","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 : 2025-02-21DOI: 10.1021/acs.analchem.4c06406
Yaojia Ai, Xuwen Gao, Xiaowen Xu, Xiaoxuan Ren, Bin Cai, Guizheng Zou
All of the commercialized electrochemiluminescence (ECL) immunoassays are automatically conducted at +1.40 V (vs Ag/AgCl) in the coreactant route. To alleviate the exogenous effect of coreactants and simplify the operation procedures, herein, a sulfur-vacancy-involved and free electron strategy is proposed to exploit Au nanoclusters (NCs) as anodic electrochemiluminophores and perform a coreactant-free immunoassay. The deficient coordination between the sulfhydryl of Met and the Au core might induce the departure of partial S atoms and enable Met-capped AuNCs (Met-AuNCs) with a sulfur-vacancy-involved electron-rich nature. The electron-rich nature tends to endow Met-AuNCs with unpaired endogenous free electrons, which can directly combine exogenous holes for light emitting. Coreactant-free ECL at around +0.86 V is consequently and conveniently achieved by merely oxidizing Met-AuNCs at the anode. The coreactant-free ECL is qualified to determine human carcinoembryonic antigen from 10 to 5000 pg/mL with a limit of detection of 5 pg/mL. Electron paramagnetic resonance provides clear evidence that endogenous free electrons within Met-AuNCs play an important role in the generation of coreactant-free ECL. This sulfur-vacancy-involved and free electron strategy is promising for designing nanoelectrochemiluminophores with improved immunoassay performance.
{"title":"Endogenous Free-Electron-Involved Coreactant-Free Electrochemiluminescence from Nanoclusters and Its Immunoassay Application","authors":"Yaojia Ai, Xuwen Gao, Xiaowen Xu, Xiaoxuan Ren, Bin Cai, Guizheng Zou","doi":"10.1021/acs.analchem.4c06406","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06406","url":null,"abstract":"All of the commercialized electrochemiluminescence (ECL) immunoassays are automatically conducted at +1.40 V (vs Ag/AgCl) in the coreactant route. To alleviate the exogenous effect of coreactants and simplify the operation procedures, herein, a sulfur-vacancy-involved and free electron strategy is proposed to exploit Au nanoclusters (NCs) as anodic electrochemiluminophores and perform a coreactant-free immunoassay. The deficient coordination between the sulfhydryl of Met and the Au core might induce the departure of partial S atoms and enable Met-capped AuNCs (Met-AuNCs) with a sulfur-vacancy-involved electron-rich nature. The electron-rich nature tends to endow Met-AuNCs with unpaired endogenous free electrons, which can directly combine exogenous holes for light emitting. Coreactant-free ECL at around +0.86 V is consequently and conveniently achieved by merely oxidizing Met-AuNCs at the anode. The coreactant-free ECL is qualified to determine human carcinoembryonic antigen from 10 to 5000 pg/mL with a limit of detection of 5 pg/mL. Electron paramagnetic resonance provides clear evidence that endogenous free electrons within Met-AuNCs play an important role in the generation of coreactant-free ECL. This sulfur-vacancy-involved and free electron strategy is promising for designing nanoelectrochemiluminophores with improved immunoassay performance.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"65 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470922","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}
MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression and are implicated in various diseases, including cancer. Due to their critical role in diagnostics, there is a growing need for sensitive, specific, and rapid detection methods for miRNAs. In this study, we present a dual-accelerated signal amplification platform for miRNA biosensing, which integrates spatial confining catalytic hairpin assembly (SC-CHA) with spherical CRISPR/Cas12a (S-CRISPR/Cas12a) system for (SC-CHA@S-CRISPR/Cas12a) trans-cleavage of hairpin DNA reporters. The method employs a biotinylated palindrome-rich assembly sequence (PAS) to form DNA nanoballs, which serve as a scaffold for the operation of SC-CHA upon miRNA binding. The SC-CHA products bind with crRNA and Cas 12a protein, activating S-CRISPR/Cas12a system to cleave the hairpin DNA reporter and generate a detectable fluorescence signal. The uniqueness of this system lies in the combined use of DNA nanoballs and hairpin DNA reporters, both of which significantly accelerate reaction kinetics, resulting in rapid signal generation. Additionally, the spherical DNA nanostructure, integrated with the S-CRISPR/Cas12a system, greatly enhances biostability and accelerating reaction kinetics. These features enable the platform to exhibit high sensitivity, with a limit of detection (LOD) as low as 13.75 fM, and excellent specificity, successfully distinguishing miRNA-21 from other miRNAs. The assay is also biostable, demonstrating reliable performance in complex biological samples such as human serum. This dual-acceleration approach offers a promising solution for sensitive, rapid, and specific miRNA biosensing, with potential applications in early cancer diagnosis and clinical monitoring.
{"title":"Dual-Accelerated Signal Amplification in Biosensing via Spatial Confining Catalytic Hairpin Assembly-Activated Spherical CRISPR/Cas12a System for Trans-Cleavage of Hairpin DNA Reporters","authors":"Zhuqi Sui, Baoqiang Chen, Jia Zhao, Haidong Yang, Longhua Guo, Jianguo Xu","doi":"10.1021/acs.analchem.4c07111","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c07111","url":null,"abstract":"MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression and are implicated in various diseases, including cancer. Due to their critical role in diagnostics, there is a growing need for sensitive, specific, and rapid detection methods for miRNAs. In this study, we present a dual-accelerated signal amplification platform for miRNA biosensing, which integrates spatial confining catalytic hairpin assembly (SC-CHA) with spherical CRISPR/Cas12a (S-CRISPR/Cas12a) system for (SC-CHA@S-CRISPR/Cas12a) trans-cleavage of hairpin DNA reporters. The method employs a biotinylated palindrome-rich assembly sequence (PAS) to form DNA nanoballs, which serve as a scaffold for the operation of SC-CHA upon miRNA binding. The SC-CHA products bind with crRNA and Cas 12a protein, activating S-CRISPR/Cas12a system to cleave the hairpin DNA reporter and generate a detectable fluorescence signal. The uniqueness of this system lies in the combined use of DNA nanoballs and hairpin DNA reporters, both of which significantly accelerate reaction kinetics, resulting in rapid signal generation. Additionally, the spherical DNA nanostructure, integrated with the S-CRISPR/Cas12a system, greatly enhances biostability and accelerating reaction kinetics. These features enable the platform to exhibit high sensitivity, with a limit of detection (LOD) as low as 13.75 fM, and excellent specificity, successfully distinguishing miRNA-21 from other miRNAs. The assay is also biostable, demonstrating reliable performance in complex biological samples such as human serum. This dual-acceleration approach offers a promising solution for sensitive, rapid, and specific miRNA biosensing, with potential applications in early cancer diagnosis and clinical monitoring.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"53 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470925","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 : 2025-02-21DOI: 10.1021/acs.analchem.4c07109
Fengli Su, Wentao Zhao, Furong Zhao, Min Cao, Tianjiao Zhu, Wei Lv, Bingzhi Li
MicroRNA-related single nucleotide polymorphisms (miR-SNPs) are promising biomarkers for cancer diagnostics, yet accurate detection methods remain limited. Here, we introduce a ligation-triggered Pyrococcus furiosus Argonaute (PfAgo) cleavage (LTAC) strategy for the sensitive detection of miR-SNPs, demonstrated using the rs11614913 SNP in miR-196a2, which is associated with nonsmall cell lung cancer (NSCLC). The mutant miR-196a2T serves as a scaffold for the formation of guide DNA (gDNA) catalyzed by the SplintR ligase, leading to PfAgo activation and enhanced fluorescence. In contrast, wild-type miR-196a2C cannot facilitate gDNA formation and thus fails to activate PfAgo. This method exhibits a linear relationship with the logarithm of the miR-196a2T concentration over a range of 0.2 pM to 100 nM, achieving a low detection limit of 0.15 pM. Analysis of NSCLC patient samples using LTAC reveals elevated levels of the rs11614913 SNP in miR-196a2 compared to healthy controls, underscoring the diagnostic potential of LTAC.
{"title":"Pyrococcus furiosus Argonaute-Based Fluorometric Biosensor for One-Tube Detection of Cancer-Associated Single Nucleotide Polymorphisms in MicroRNAs","authors":"Fengli Su, Wentao Zhao, Furong Zhao, Min Cao, Tianjiao Zhu, Wei Lv, Bingzhi Li","doi":"10.1021/acs.analchem.4c07109","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c07109","url":null,"abstract":"MicroRNA-related single nucleotide polymorphisms (miR-SNPs) are promising biomarkers for cancer diagnostics, yet accurate detection methods remain limited. Here, we introduce a ligation-triggered <i>Pyrococcus furiosus</i> Argonaute (<i>Pf</i>Ago) cleavage (LTAC) strategy for the sensitive detection of miR-SNPs, demonstrated using the rs11614913 SNP in miR-196a2, which is associated with nonsmall cell lung cancer (NSCLC). The mutant miR-196a2T serves as a scaffold for the formation of guide DNA (gDNA) catalyzed by the SplintR ligase, leading to <i>Pf</i>Ago activation and enhanced fluorescence. In contrast, wild-type miR-196a2C cannot facilitate gDNA formation and thus fails to activate <i>Pf</i>Ago. This method exhibits a linear relationship with the logarithm of the miR-196a2T concentration over a range of 0.2 pM to 100 nM, achieving a low detection limit of 0.15 pM. Analysis of NSCLC patient samples using LTAC reveals elevated levels of the rs11614913 SNP in miR-196a2 compared to healthy controls, underscoring the diagnostic potential of LTAC.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"30 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470955","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 : 2025-02-21DOI: 10.1021/acs.analchem.4c04108
Christopher Bahro, Pavel Sengupta, Dipankar Koley
Nonaqueous electroanalytical experiments require a stable and mechanically robust reference electrode (RE). The primary role of an RE is to maintain constant cell potential. Ag/Ag+ and Ag/AgCl are the most widely used REs in nonaqueous electrochemistry due to their robustness, but the disadvantages of chemical and ionic contamination and potential drifts from nonspecific Ag+ activity have caused a shift toward polymer back contact-based solid-state reference electrodes (SSREs). Most polymer-based nonaqueous REs, however, suffer from a lack of structural integrity, exhibit potential drifting, and have ill-defined potential. In this work, a self-doped poly(3,4-ethylenedioxythiophene) and poly(3,4-ethylenedioxythiophene) sulfonated or PEDOT/PEDOT-S (S = sulfonated) polymer-based SSRE was fabricated with high mechanical durability and chemical stability. An unbound sulfonate anion in the EDOT-S polymer backbone of this SSRE increases chemical and mechanical stability. PEDOT/PEDOT-S electrodeposited stainless-steel wires with a commercial polytetrafluoroethylene (PTFE) coating have been fabricated and further optimized with an inner filling of 0.1 M TBAPF6/acetonitrile solution. A potential drift of 2.65 μV/h for the SSRE without an inner filling solution and 1.72 μV/h for the SSRE with it (n = 3) vs Fc/Fc+ were achieved after testing for 14 days. Mechanical bending and twisting of the SSRE preserved the polymer coating, RE function, and mechanical stability. The SSRE with the inner filling solution has been successfully used in nonaqueous electroanalytical and electrolysis applications. The SSRE can be reused after storing without a supporting nonaqueous solution, allowing for the possibility of prolonged dry storage and easy shipping.
{"title":"PEDOT/PEDOT-S Copolymer-Based Nonaqueous Solid-State Reference Electrode with High Electrochemical and Mechanical Stability","authors":"Christopher Bahro, Pavel Sengupta, Dipankar Koley","doi":"10.1021/acs.analchem.4c04108","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c04108","url":null,"abstract":"Nonaqueous electroanalytical experiments require a stable and mechanically robust reference electrode (RE). The primary role of an RE is to maintain constant cell potential. Ag/Ag<sup>+</sup> and Ag/AgCl are the most widely used REs in nonaqueous electrochemistry due to their robustness, but the disadvantages of chemical and ionic contamination and potential drifts from nonspecific Ag<sup>+</sup> activity have caused a shift toward polymer back contact-based solid-state reference electrodes (SSREs). Most polymer-based nonaqueous REs, however, suffer from a lack of structural integrity, exhibit potential drifting, and have ill-defined potential. In this work, a self-doped poly(3,4-ethylenedioxythiophene) and poly(3,4-ethylenedioxythiophene) sulfonated or PEDOT/PEDOT-S (S = sulfonated) polymer-based SSRE was fabricated with high mechanical durability and chemical stability. An unbound sulfonate anion in the EDOT-S polymer backbone of this SSRE increases chemical and mechanical stability. PEDOT/PEDOT-S electrodeposited stainless-steel wires with a commercial polytetrafluoroethylene (PTFE) coating have been fabricated and further optimized with an inner filling of 0.1 M TBAPF<sub>6</sub>/acetonitrile solution. A potential drift of 2.65 μV/h for the SSRE without an inner filling solution and 1.72 μV/h for the SSRE with it (<i>n</i> = 3) vs Fc/Fc<sup>+</sup> were achieved after testing for 14 days. Mechanical bending and twisting of the SSRE preserved the polymer coating, RE function, and mechanical stability. The SSRE with the inner filling solution has been successfully used in nonaqueous electroanalytical and electrolysis applications. The SSRE can be reused after storing without a supporting nonaqueous solution, allowing for the possibility of prolonged dry storage and easy shipping.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"25 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462224","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}
Organic photoelectrochemical transistor (OPECT) has undergone significant advancements, enabling an effective synergy between organic electronics and photoelectrochemistry, contributing to opto-logic gates, neuromorphic emulation, and biological detection. However, feasible OPECT operation is still quite limited and the associated technology is evolving. This study introduces a self-enhancement OPECT operation facilitated by triple-functional stimuli-responsive organic molecules (SROM). The representative SROM sensitizes the photogate to selectively recognize the chosen target, where the reaction product serves to reengineer band alignment, resulting in a self-enhanced OPECT modulation. We further leverage this effect to implement highly selective detection of sulfite. The findings of this work bridge the gap between OPECT and SROM, demonstrating the significant potential of SROM in a unique OPECT operation and implementation.
{"title":"Triple-Functional Smart Organic Molecules Enable Self-Enhancement Modulation of Organic Photoelectrochemical Transistor","authors":"Jin-Ming Zhang, Yuan Gao, Yuan-Cheng Zhu, Rui Ban, Yu-Mei Li, Haijun Du, Feng-Zao Chen, Wei-Wei Zhao","doi":"10.1021/acs.analchem.4c05193","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c05193","url":null,"abstract":"Organic photoelectrochemical transistor (OPECT) has undergone significant advancements, enabling an effective synergy between organic electronics and photoelectrochemistry, contributing to opto-logic gates, neuromorphic emulation, and biological detection. However, feasible OPECT operation is still quite limited and the associated technology is evolving. This study introduces a self-enhancement OPECT operation facilitated by triple-functional stimuli-responsive organic molecules (SROM). The representative SROM sensitizes the photogate to selectively recognize the chosen target, where the reaction product serves to reengineer band alignment, resulting in a self-enhanced OPECT modulation. We further leverage this effect to implement highly selective detection of sulfite. The findings of this work bridge the gap between OPECT and SROM, demonstrating the significant potential of SROM in a unique OPECT operation and implementation.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"1 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143470900","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 : 2025-02-21DOI: 10.1021/acs.analchem.4c06462
Hongrui Zhang, Ya-nan Zhang, Like Li, Xuegang Li, Yong Zhao
A method for the determination of cholesterol using rhodamine derivatives as chromogenic substrates was proposed in this study. The oxidation of rhodamine B hydrazide (RBH) by hydrogen peroxide (H2O2) was catalyzed by a peroxide-mimicking enzyme to produce the fluorescent product. The reaction was further combined with the oxidase system to achieve indirect determination of cholesterol concentration, which can be catalyzed by cholesterol oxidase to produce H2O2 as an intermediate product. Optical fiber optofluidic lasers (FOFLs), as a sensitive biochemical detection platform, have the ability to distinguish small differences in the amount of fluorescence products generated by the reaction and were used to achieve sensitive cholesterol detection. Under optimized experimental conditions, the dynamic range of three orders of magnitude was obtained in the determination of H2O2 with a lower limit of detection (LOD) of 1.63 μM, and the assay time was as short as 3.5 min. On this basis, the designed cholesterol sensor obtained a linear range of 2.55–652.67 μM with a lower LOD of 2.55 μM and proved to have good selectivity. The possibility of cholesterol determination in human serum was initially tested. The sensor was also characterized by easy signal collection, wash-free procedure, controlled sample consumption, fast assay, low cost, and simple operation.
{"title":"An Enzyme-Catalyzed Optical Fiber Optofluidic Laser Sensor for Cholesterol Detection Using Rhodamine B Hydrazide","authors":"Hongrui Zhang, Ya-nan Zhang, Like Li, Xuegang Li, Yong Zhao","doi":"10.1021/acs.analchem.4c06462","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06462","url":null,"abstract":"A method for the determination of cholesterol using rhodamine derivatives as chromogenic substrates was proposed in this study. The oxidation of rhodamine B hydrazide (RBH) by hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) was catalyzed by a peroxide-mimicking enzyme to produce the fluorescent product. The reaction was further combined with the oxidase system to achieve indirect determination of cholesterol concentration, which can be catalyzed by cholesterol oxidase to produce H<sub>2</sub>O<sub>2</sub> as an intermediate product. Optical fiber optofluidic lasers (FOFLs), as a sensitive biochemical detection platform, have the ability to distinguish small differences in the amount of fluorescence products generated by the reaction and were used to achieve sensitive cholesterol detection. Under optimized experimental conditions, the dynamic range of three orders of magnitude was obtained in the determination of H<sub>2</sub>O<sub>2</sub> with a lower limit of detection (LOD) of 1.63 μM, and the assay time was as short as 3.5 min. On this basis, the designed cholesterol sensor obtained a linear range of 2.55–652.67 μM with a lower LOD of 2.55 μM and proved to have good selectivity. The possibility of cholesterol determination in human serum was initially tested. The sensor was also characterized by easy signal collection, wash-free procedure, controlled sample consumption, fast assay, low cost, and simple operation.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"209 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462226","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 : 2025-02-21DOI: 10.1021/acs.analchem.4c06580
Selene Fiori, Christoph Bruckschlegel, Katharina Weiss, Keyu Su, Michael Foedlmeier, Flavio Della Pelle, Annalisa Scroccarello, Dario Compagnone, Antje J. Baeumner, Nongnoot Wongkaew
A novel breathable electrochemical enzyme-free sensor made from laser-induced carbon nanofibers embedding Ni nanocatalysts (Ni-LCNFs) is proposed for the capture and detection of biomarkers in breath aerosol. The permeable Ni-LCNF electrodes were fabricated on filter paper where a hydrophobic wax barrier was created to confine the device’s working area. The device was tested with aerosolized glucose, which was collected on the porous Ni-LCNF electrode. After a subsequent drying step, 0.1 M NaOH was dropped onto the device, and the electrocatalytic reaction of the captured glucose enabled by a Ni nanocatalyst was monitored via cyclic voltammetry (CV). Taking the oxidation/reduction peak ratios from CV as analytical signals improves the reliability and reproducibility of the glucose measurement. In the measurement step, closing the sensing area with adhesive tape, named closed device, enhances the detection sensitivity and enables the detection limit of 0.71 μM, which is 11.5 and 50 times, respectively, better when compared to the open device configuration. Measurements with simulated glucose aerosols containing clinically relevant glucose levels and comparison to screen-printed electrodes demonstrated the device’s superiority for breath analysis. Although in vivo validation studies must be conducted in future work, the proposed device results in a captivating point-of-care device integratable in breathing masks and breath analysis devices.
{"title":"Laser-Induced Carbon Nanofibers as Permeable Nonenzymatic Sensor for Biomarker Detection in Breath Aerosol","authors":"Selene Fiori, Christoph Bruckschlegel, Katharina Weiss, Keyu Su, Michael Foedlmeier, Flavio Della Pelle, Annalisa Scroccarello, Dario Compagnone, Antje J. Baeumner, Nongnoot Wongkaew","doi":"10.1021/acs.analchem.4c06580","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06580","url":null,"abstract":"A novel breathable electrochemical enzyme-free sensor made from laser-induced carbon nanofibers embedding Ni nanocatalysts (Ni-LCNFs) is proposed for the capture and detection of biomarkers in breath aerosol. The permeable Ni-LCNF electrodes were fabricated on filter paper where a hydrophobic wax barrier was created to confine the device’s working area. The device was tested with aerosolized glucose, which was collected on the porous Ni-LCNF electrode. After a subsequent drying step, 0.1 M NaOH was dropped onto the device, and the electrocatalytic reaction of the captured glucose enabled by a Ni nanocatalyst was monitored via cyclic voltammetry (CV). Taking the oxidation/reduction peak ratios from CV as analytical signals improves the reliability and reproducibility of the glucose measurement. In the measurement step, closing the sensing area with adhesive tape, named <i>closed device</i>, enhances the detection sensitivity and enables the detection limit of 0.71 μM, which is 11.5 and 50 times, respectively, better when compared to the <i>open device</i> configuration. Measurements with simulated glucose aerosols containing clinically relevant glucose levels and comparison to screen-printed electrodes demonstrated the device’s superiority for breath analysis. Although <i>in vivo</i> validation studies must be conducted in future work, the proposed device results in a captivating point-of-care device integratable in breathing masks and breath analysis devices.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"31 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143462227","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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