Creating biosensors capable of facilely and entirely excluding the influence of interfering biomolecules in complex samples holds profound significance for advancing detection technology and diagnostics. Here, we develop a wireless portable biosensor (WPB) that prevents interference from abundant biomolecules in serum through homogeneous hybridization and S9.6 antibody-mediated multivalent capture. By transferring the hybridization environment from a heterogeneous chip surface to a homogeneous solution, the biosensor maintains consistent hybridization efficiency in serum as in buffer. Additionally, the use of S9.6 antibody-mediated multivalent capture ensures nearly unchanged binding affinity in serum compared to buffer. On the basis of the multiple affinity enhancements, S9.6 antibody-mediated WPB can achieve ultrasensitive detection of nucleic acid in 50% human serum. Specifically, a subtle blocker is designed to eliminate the competitive monovalent S9.6 antibody–heteroduplex binding, ensuring the efficiency of multivalent S9.6 antibody–heteroduplex interactions. The blocker also enables single-step detection. Moreover, the sensing platform utilizes interferents in serum as in situ antifouling biomolecules to prevent nonspecific adsorption. As a result, the proposed WPB achieves a similar limit of detection for nucleic acids in human serum (95 aM) and in buffer (86 aM). This approach inspires a new idea for complex interference elimination and usage and exhibits comprehensive detection performance in complex samples with potential future diagnostic applications.
{"title":"S9.6 Antibody-Mediated Wireless Portable Biosensor with Multiple Affinity Enhancements for Comprehensive Detection of Nucleic Acid in Serum","authors":"Yi Wang, Zeyu Ma, Yingjing Li, Hongyan Yang, Jia Jin, Yuxia Jin, Guobao Zhou","doi":"10.1021/acs.analchem.5c00566","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c00566","url":null,"abstract":"Creating biosensors capable of facilely and entirely excluding the influence of interfering biomolecules in complex samples holds profound significance for advancing detection technology and diagnostics. Here, we develop a wireless portable biosensor (WPB) that prevents interference from abundant biomolecules in serum through homogeneous hybridization and S9.6 antibody-mediated multivalent capture. By transferring the hybridization environment from a heterogeneous chip surface to a homogeneous solution, the biosensor maintains consistent hybridization efficiency in serum as in buffer. Additionally, the use of S9.6 antibody-mediated multivalent capture ensures nearly unchanged binding affinity in serum compared to buffer. On the basis of the multiple affinity enhancements, S9.6 antibody-mediated WPB can achieve ultrasensitive detection of nucleic acid in 50% human serum. Specifically, a subtle blocker is designed to eliminate the competitive monovalent S9.6 antibody–heteroduplex binding, ensuring the efficiency of multivalent S9.6 antibody–heteroduplex interactions. The blocker also enables single-step detection. Moreover, the sensing platform utilizes interferents in serum as in situ antifouling biomolecules to prevent nonspecific adsorption. As a result, the proposed WPB achieves a similar limit of detection for nucleic acids in human serum (95 aM) and in buffer (86 aM). This approach inspires a new idea for complex interference elimination and usage and exhibits comprehensive detection performance in complex samples with potential future diagnostic applications.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"16 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862489","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}
We present an ambient mass spectrometry immunoassay platform based on specific mass tags detected by laser ablation-dielectric barrier discharge ionization-mass spectrometry (LA-DBDI-MS). It features high sensitivity, multiplexed quantitation, minimal sample consumption, and convenient operation. The organic small-molecule mass tags allow very high sensitivity and quantitative detection of multiple proteins, even of membrane-bound proteins on cell surfaces, through signal amplification (approximately 600 times). By using just 2 μL of serum, we achieved the detection of thrombin (LOD 6.6 pM) and cancer antigen 125 (CA125) (LOD 1.4 U/mL). Seven protein biomarkers, including CA125, carcinoembryonic antigen (CEA), epithelial cell adhesion molecule (EpCAM), protein tyrosine kinase 7 (PTK7), transferrin receptor 1 (CD71), cluster of differentiation 8 alpha protein (CD8a), and cluster of differentiation 33 (CD33), were simultaneously detected in situ in four types of cancer cells within 2 h. This platform is expected to enable multiplexed protein detection in single-drop samples or at the single-cell scale, distinguish different types of cells, and has potential applications in clinical diagnosis.
{"title":"Multiplexed Detection of Tumor Markers and Discrimination of Cancer Cell Types by Laser Ablation-Dielectric Barrier Discharge Ionization-Mass Spectrometry","authors":"Xiaokang Guan, Qiao Lu, Naijie Wei, Shuxian Liu, Haowen Li, Qin Wu, Xiaowen Yan, Renato Zenobi","doi":"10.1021/acs.analchem.4c06927","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06927","url":null,"abstract":"We present an ambient mass spectrometry immunoassay platform based on specific mass tags detected by laser ablation-dielectric barrier discharge ionization-mass spectrometry (LA-DBDI-MS). It features high sensitivity, multiplexed quantitation, minimal sample consumption, and convenient operation. The organic small-molecule mass tags allow very high sensitivity and quantitative detection of multiple proteins, even of membrane-bound proteins on cell surfaces, through signal amplification (approximately 600 times). By using just 2 μL of serum, we achieved the detection of thrombin (LOD 6.6 pM) and cancer antigen 125 (CA125) (LOD 1.4 U/mL). Seven protein biomarkers, including CA125, carcinoembryonic antigen (CEA), epithelial cell adhesion molecule (EpCAM), protein tyrosine kinase 7 (PTK7), transferrin receptor 1 (CD71), cluster of differentiation 8 alpha protein (CD8a), and cluster of differentiation 33 (CD33), were simultaneously detected in situ in four types of cancer cells within 2 h. This platform is expected to enable multiplexed protein detection in single-drop samples or at the single-cell scale, distinguish different types of cells, and has potential applications in clinical diagnosis.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"219 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862488","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 : 2025-04-21DOI: 10.1021/acs.analchem.4c05421
Xiaojun Liu, Qingquan Zhang, Chenghua Zong, Hongwei Gai
This article has not yet been cited by other publications.
{"title":"Digital Immunoassay for Proteins: Theory, Methodology, and Clinical Applications","authors":"Xiaojun Liu, Qingquan Zhang, Chenghua Zong, Hongwei Gai","doi":"10.1021/acs.analchem.4c05421","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c05421","url":null,"abstract":"This article has not yet been cited by other publications.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"37 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853762","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 : 2025-04-21DOI: 10.1021/acs.analchem.4c05003
Malek Elsayyid, Jessica E. Tanis, Yanbao Yu
Caenorhabditis elegans is a widely used genetic model organism; however, the worm cuticle complicates extraction of intracellular proteins, a prerequisite for typical bottom-up proteomics. Conventional physical disruption procedures are not only time-consuming but can also cause significant sample loss, making it difficult to perform proteomics with low-input samples. Here, for the first time, we present an on-filter in-cell (OFIC) processing approach that can digest C. elegans proteins directly in the cells of the organism after methanol fixation. With OFIC processing and single-shot LC-MS analysis, we identified over 9400 proteins from a sample of only 200 worms, the largest C. elegans proteome reported to date that did not require fractionation or enrichment. We systematically evaluated the performance of the OFIC approach by comparing it to conventional lysis-based methods. Our data suggest superior performance of OFIC processing for C. elegans proteome identification and quantitation. We further evaluated the OFIC approach with even lower-input samples, including single worms. Then, we used this method to determine how the proteome is impacted by loss of superoxide dismutase sod-1, the ortholog of human SOD1, a gene associated with amyotrophic lateral sclerosis. Analysis of 8800 proteins from only 50 worms as the initial input showed that loss of sod-1 affects the abundance of proteins required for stress response, ribosome biogenesis, and metabolism. In conclusion, our streamlined OFIC approach, which can be broadly applied to other systems, minimizes sample loss while offering the simplest workflow reported to date for C. elegans proteomics.
{"title":"Simple In-Cell Processing Enables Deep Proteome Analysis of Low-Input Caenorhabditis elegans","authors":"Malek Elsayyid, Jessica E. Tanis, Yanbao Yu","doi":"10.1021/acs.analchem.4c05003","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c05003","url":null,"abstract":"<i>Caenorhabditis elegans</i> is a widely used genetic model organism; however, the worm cuticle complicates extraction of intracellular proteins, a prerequisite for typical bottom-up proteomics. Conventional physical disruption procedures are not only time-consuming but can also cause significant sample loss, making it difficult to perform proteomics with low-input samples. Here, for the first time, we present an on-filter in-cell (OFIC) processing approach that can digest <i>C. elegans</i> proteins directly in the cells of the organism after methanol fixation. With OFIC processing and single-shot LC-MS analysis, we identified over 9400 proteins from a sample of only 200 worms, the largest <i>C. elegans</i> proteome reported to date that did not require fractionation or enrichment. We systematically evaluated the performance of the OFIC approach by comparing it to conventional lysis-based methods. Our data suggest superior performance of OFIC processing for <i>C. elegans</i> proteome identification and quantitation. We further evaluated the OFIC approach with even lower-input samples, including single worms. Then, we used this method to determine how the proteome is impacted by loss of superoxide dismutase <i>sod-1</i>, the ortholog of human <i>SOD1</i>, a gene associated with amyotrophic lateral sclerosis. Analysis of 8800 proteins from only 50 worms as the initial input showed that loss of <i>sod-1</i> affects the abundance of proteins required for stress response, ribosome biogenesis, and metabolism. In conclusion, our streamlined OFIC approach, which can be broadly applied to other systems, minimizes sample loss while offering the simplest workflow reported to date for <i>C. elegans</i> proteomics.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"64 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857458","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 : 2025-04-21DOI: 10.1021/acs.analchem.4c06796
Anna Lalik, Julia Szreder, Mirosława Grymel, Sebastian Żabczyński, Sylwia Bajkacz, Mateusz Pielok, Mirosław Cieślik, Agnieszka Kicińska, Agata Wawrzkiewicz-Jałowiecka
Published as part of <i>Analytical Chemistry</i> special issue “Fundamental and Applied Reviews in Analytical Chemistry 2025”. <b>Anna Lalik</b> studied biotechnology at the Wrocław University of Science and Technology (Poland), where she received an MSc in the field of molecular biotechnology and biocatalysis. In 2005, she obtained a PhD in chemical sciences, also from the Wrocław University of Science and Technology (Poland). Since 2006, she has been working at the Silesian University of Technology (Poland): for the first 3 years as a postdoc and later as an assistant professor. Her research focuses on studying the regulation of cellular pathways by biologically active biomolecules. <b>Julia Szreder</b> studied chemistry at the Silesian University of Technology in Gliwice, Poland, in the Department of Organic Chemistry, Bioorganic Chemistry, and Biotechnology at the Faculty of Chemistry. She earned her engineering degree in 2022 and her master’s degree in 2023. After graduation, she began a PhD in chemical sciences. She is currently in the second year of her doctoral studies, focusing on the use of sugars to enhance the pharmacokinetic properties of biologically active compounds. <b>Mirosława Grymel</b> graduated from the Faculty of Chemistry of the Silesian University of Technology, Poland. In 2001, she obtained PhD in Chemistry with distinction. Currently, she works in a research and teaching position at the Department of Organic Chemistry, Bioorganic Chemistry, and Biotechnology of the Silesian University of Technology. Her main research interests are focused on the chemistry of organophosphorus compounds with a special emphasis on structural modifications of natural bioactive compounds (e.g., betulin, spilanthol). She specializes in the isolation of bioactive ingredients from plant extracts and elucidating the structures of novel organic compounds using spectroscopic methods, including nuclear magnetic resonance and infrared spectroscopy. In her educational role, she has also successfully supervised interdisciplinary student teams through the implementation of Project-Based Learning initiatives multiple times. <b>Sebastian Żabczyński</b> graduated from the Silesian University of Technology (Poland), receiving a Master of Science in Engineering degree from the Faculty of Environmental Engineering and Energy. In 2002, he obtained a PhD in technical sciences in the field of environmental engineering, also from the Silesian University of Technology (Poland). He worked for one year each as a postdoctoral researcher at the Swiss Federal Institute of Aquatic Science and Technology (EAWAG, Switzerland). His research focuses mainly on the removal of micropollutants from the environment using biological and physicochemical methods, as well as the biological production of hydrogen. <b>Sylwia Bajkacz</b> studied chemistry at the Silesian University of Technology (Poland), where she received her Diploma and Ph.D. degrees in 2008 and 2012, and in 2016 Ha
{"title":"Estrogens and Progestogens in Environmental Waters: Analytical Chemistry and Biosensing Perspectives on Methods, Challenges, and Trends","authors":"Anna Lalik, Julia Szreder, Mirosława Grymel, Sebastian Żabczyński, Sylwia Bajkacz, Mateusz Pielok, Mirosław Cieślik, Agnieszka Kicińska, Agata Wawrzkiewicz-Jałowiecka","doi":"10.1021/acs.analchem.4c06796","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06796","url":null,"abstract":"Published as part of <i>Analytical Chemistry</i> special issue “Fundamental and Applied Reviews in Analytical Chemistry 2025”. <b>Anna Lalik</b> studied biotechnology at the Wrocław University of Science and Technology (Poland), where she received an MSc in the field of molecular biotechnology and biocatalysis. In 2005, she obtained a PhD in chemical sciences, also from the Wrocław University of Science and Technology (Poland). Since 2006, she has been working at the Silesian University of Technology (Poland): for the first 3 years as a postdoc and later as an assistant professor. Her research focuses on studying the regulation of cellular pathways by biologically active biomolecules. <b>Julia Szreder</b> studied chemistry at the Silesian University of Technology in Gliwice, Poland, in the Department of Organic Chemistry, Bioorganic Chemistry, and Biotechnology at the Faculty of Chemistry. She earned her engineering degree in 2022 and her master’s degree in 2023. After graduation, she began a PhD in chemical sciences. She is currently in the second year of her doctoral studies, focusing on the use of sugars to enhance the pharmacokinetic properties of biologically active compounds. <b>Mirosława Grymel</b> graduated from the Faculty of Chemistry of the Silesian University of Technology, Poland. In 2001, she obtained PhD in Chemistry with distinction. Currently, she works in a research and teaching position at the Department of Organic Chemistry, Bioorganic Chemistry, and Biotechnology of the Silesian University of Technology. Her main research interests are focused on the chemistry of organophosphorus compounds with a special emphasis on structural modifications of natural bioactive compounds (e.g., betulin, spilanthol). She specializes in the isolation of bioactive ingredients from plant extracts and elucidating the structures of novel organic compounds using spectroscopic methods, including nuclear magnetic resonance and infrared spectroscopy. In her educational role, she has also successfully supervised interdisciplinary student teams through the implementation of Project-Based Learning initiatives multiple times. <b>Sebastian Żabczyński</b> graduated from the Silesian University of Technology (Poland), receiving a Master of Science in Engineering degree from the Faculty of Environmental Engineering and Energy. In 2002, he obtained a PhD in technical sciences in the field of environmental engineering, also from the Silesian University of Technology (Poland). He worked for one year each as a postdoctoral researcher at the Swiss Federal Institute of Aquatic Science and Technology (EAWAG, Switzerland). His research focuses mainly on the removal of micropollutants from the environment using biological and physicochemical methods, as well as the biological production of hydrogen. <b>Sylwia Bajkacz</b> studied chemistry at the Silesian University of Technology (Poland), where she received her Diploma and Ph.D. degrees in 2008 and 2012, and in 2016 Ha","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"138 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853764","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 : 2025-04-21DOI: 10.1021/acs.analchem.5c01677
Axell Rodriguez, Yana Purvinsh, Junjie Zhang, Artem S. Rogovskyy, Dmitry Kurouski
Every year, bacterial infections are responsible for over 7 million deaths globally. Timely detection and identification of these pathogens enable timely administration of antimicrobial agents, which can save thousands of lives. Most of the currently known approaches that can address these needs are time- and labor consuming. In this study, we examine the potential of innovative nano-infrared spectroscopy, also known as atomic force microscopy infrared (AFM-IR) spectroscopy, and machine learning in the identification of different bacteria. We demonstrate that a single bacteria cell is sufficient to identify Borreliella burgdorferi, Escherichia coli, Mycobacterium smegmatis, and two strains of Acinetobacter baumannii with 100% accuracy. The identification is based on the vibrational bands that originate from the components of the cell wall as well as the interior biomolecules of the bacterial cell. These results indicate that nano-IR spectroscopy can be used for the nondestructive, confirmatory, and label-free identification of pathogenic microorganisms at the single-cell level.
{"title":"Nano-Infrared Detection and Identification of Bacteria at the Single-Cell Level","authors":"Axell Rodriguez, Yana Purvinsh, Junjie Zhang, Artem S. Rogovskyy, Dmitry Kurouski","doi":"10.1021/acs.analchem.5c01677","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c01677","url":null,"abstract":"Every year, bacterial infections are responsible for over 7 million deaths globally. Timely detection and identification of these pathogens enable timely administration of antimicrobial agents, which can save thousands of lives. Most of the currently known approaches that can address these needs are time- and labor consuming. In this study, we examine the potential of innovative nano-infrared spectroscopy, also known as atomic force microscopy infrared (AFM-IR) spectroscopy, and machine learning in the identification of different bacteria. We demonstrate that a single bacteria cell is sufficient to identify <i>Borreliella burgdorferi</i>, <i>Escherichia coli</i>, <i>Mycobacterium smegmatis,</i> and two strains of <i>Acinetobacter baumannii</i> with 100% accuracy. The identification is based on the vibrational bands that originate from the components of the cell wall as well as the interior biomolecules of the bacterial cell. These results indicate that nano-IR spectroscopy can be used for the nondestructive, confirmatory, and label-free identification of pathogenic microorganisms at the single-cell level.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"5 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857315","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 : 2025-04-21DOI: 10.1021/acs.analchem.4c03388
Shannon A. Raab, Hua Pan, Daniel W. Woodall, David A. Hales, Edie M. Sharon, David E. Clemmer
Structural transitions of the model system cytochrome c (Cyt c) were monitored by ion mobility spectrometry (IMS) and mass spectrometry (MS) paired with two methods to heat proteins: a variable-temperature electrospray ionization (vT-ESI) source to heat the bulk protein solution and a 10.6 μm CO2 laser to rapidly heat ESI droplets containing the protein. Previous evidence from our group suggests that information about time-dependent protein structural transitions can be accessed by irradiating protein droplets of different sizes. In this paper, a new method to control droplet sizes is introduced where the distance between the ESI emitter and laser path is altered to produce larger or smaller droplets, yielding a simple and robust means of accessing different protein unfolding timescales. Herein, increasing the temperature of a solution of Cyt c in water at pH 4 via vT-ESI (from 27 to 80 °C) shifts the distribution of states from a relatively folded ensemble consisting of low charge states to a distribution of elongated structures that are observed as highly charged species. Rapid heating of ESI droplets (containing Cyt c) with a variable-power CO2 laser yields a similar shift in the mass spectra with increasing laser power. To investigate the conformational changes accessible within the lifetime of the heated droplets, four different tip sizes as well as several different distances between the ESI emitter and laser path are studied. Slight changes in droplet size can greatly alter the response of the protein to the laser field. The maximum observable charge state upon laser heating appears to be limited by the size of the ESI droplet prior to entering the laser field. The dependence of these distributions on droplets sizes leads us to propose that laser-induced denaturation in ESI droplets is stopped before an equilibrium distribution of conformers can be reached─providing a means of kinetically trapping ensembles of states. Therefore, we provide a simple correlation between droplet size, percent protein folded, and appropriate experimental distance to suggest a framework for robust studies of protein denaturation in ESI droplets.
{"title":"Laser-Induced Denaturation of Cytochrome c in Electrospray Droplets","authors":"Shannon A. Raab, Hua Pan, Daniel W. Woodall, David A. Hales, Edie M. Sharon, David E. Clemmer","doi":"10.1021/acs.analchem.4c03388","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c03388","url":null,"abstract":"Structural transitions of the model system cytochrome <i>c</i> (Cyt <i>c</i>) were monitored by ion mobility spectrometry (IMS) and mass spectrometry (MS) paired with two methods to heat proteins: a variable-temperature electrospray ionization (vT-ESI) source to heat the bulk protein solution and a 10.6 μm CO<sub>2</sub> laser to rapidly heat ESI droplets containing the protein. Previous evidence from our group suggests that information about time-dependent protein structural transitions can be accessed by irradiating protein droplets of different sizes. In this paper, a new method to control droplet sizes is introduced where the distance between the ESI emitter and laser path is altered to produce larger or smaller droplets, yielding a simple and robust means of accessing different protein unfolding timescales. Herein, increasing the temperature of a solution of Cyt <i>c</i> in water at pH 4 via vT-ESI (from 27 to 80 °C) shifts the distribution of states from a relatively folded ensemble consisting of low charge states to a distribution of elongated structures that are observed as highly charged species. Rapid heating of ESI droplets (containing Cyt <i>c</i>) with a variable-power CO<sub>2</sub> laser yields a similar shift in the mass spectra with increasing laser power. To investigate the conformational changes accessible within the lifetime of the heated droplets, four different tip sizes as well as several different distances between the ESI emitter and laser path are studied. Slight changes in droplet size can greatly alter the response of the protein to the laser field. The maximum observable charge state upon laser heating appears to be limited by the size of the ESI droplet prior to entering the laser field. The dependence of these distributions on droplets sizes leads us to propose that laser-induced denaturation in ESI droplets is stopped before an equilibrium distribution of conformers can be reached─providing a means of kinetically trapping ensembles of states. Therefore, we provide a simple correlation between droplet size, percent protein folded, and appropriate experimental distance to suggest a framework for robust studies of protein denaturation in ESI droplets.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"47 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857606","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}
Despite concerns about methylmercury (MeHg) contamination in rice, the sources and transformation mechanisms of MeHg within paddy field water, the primary source of MeHg in rice, remain unclear. Determination of the isotopic composition of MeHg in paddy water is crucial to clarify these processes. However, there is a lack of sampling and analytical methods for quantifying MeHg isotopes in water samples. In this study, we use diffusive gradients in thin films (DGT) in situ to collect MeHg from paddy water to determine the concentration of MeHg and the associated isotopic composition. This technique enables high collection efficiency of aqueous MeHg with limited Hg isotope mass-dependent fractionation (∼− 0.2‰ δ202Hg) and mass-independent fractionation (<0.1‰ Δ199Hg). Field applications using the developed DGT method suggest that in situ methylation of soluble Hg(II) drives the generation of MeHg in paddy water. MeHg in overlying water exhibits a Δ199Hg/Δ201Hg ratio of 1.07 ± 0.09, indicating significant photoreduction of aqueous Hg(II) before methylation. The absence of photodemethylation Δ199Hg/Δ201Hg ratio (∼1.36) suggests limited MeHg demethylation in the overlying water. This study provides insights into the sources and transformation of MeHg in rice paddies and helps develop mitigation strategies to reduce MeHg exposure through rice consumption.
{"title":"Sources and Transformation of Methylmercury in Paddy Water: Insights from Mercury Isotopes Collected by Diffusive Gradients in Thin Films","authors":"Hongqian Yin, Heng Yao, Bo Meng, Che-Jen Lin, Wei Yuan, Runsheng Yin, Ping Li, Chaoyue Chen, Qiang Pu, Kun Zhang, Guangyi Sun, Hua Zhang, Xinbin Feng","doi":"10.1021/acs.analchem.4c06132","DOIUrl":"https://doi.org/10.1021/acs.analchem.4c06132","url":null,"abstract":"Despite concerns about methylmercury (MeHg) contamination in rice, the sources and transformation mechanisms of MeHg within paddy field water, the primary source of MeHg in rice, remain unclear. Determination of the isotopic composition of MeHg in paddy water is crucial to clarify these processes. However, there is a lack of sampling and analytical methods for quantifying MeHg isotopes in water samples. In this study, we use diffusive gradients in thin films (DGT) <i>in situ</i> to collect MeHg from paddy water to determine the concentration of MeHg and the associated isotopic composition. This technique enables high collection efficiency of aqueous MeHg with limited Hg isotope mass-dependent fractionation (∼− 0.2‰ δ<sup>202</sup>Hg) and mass-independent fractionation (<0.1‰ Δ<sup>199</sup>Hg). Field applications using the developed DGT method suggest that <i>in situ</i> methylation of soluble Hg(II) drives the generation of MeHg in paddy water. MeHg in overlying water exhibits a Δ<sup>199</sup>Hg/Δ<sup>201</sup>Hg ratio of 1.07 ± 0.09, indicating significant photoreduction of aqueous Hg(II) before methylation. The absence of photodemethylation Δ<sup>199</sup>Hg/Δ<sup>201</sup>Hg ratio (∼1.36) suggests limited MeHg demethylation in the overlying water. This study provides insights into the sources and transformation of MeHg in rice paddies and helps develop mitigation strategies to reduce MeHg exposure through rice consumption.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"1 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857459","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 : 2025-04-21DOI: 10.1021/acs.analchem.5c00707
Ai-Xin Ma, Leping Lin, Qing Zhang, Ming-Yu Zhang, Lin-Han Jiang, Jiaxuan Chen, Shu-Lin Liu, Zhi-Gang Wang, Dai-Wen Pang
Viral–bacterial coinfections present intricate pathologies that exacerbate disease progression and elevate mortality rates. Understanding the dynamic interplay between viruses and bacteria during coinfection is critical for developing effective therapeutic interventions. However, current diagnostic tools primarily rely on static detection methods, limiting their ability to monitor real-time infection dynamics. Here, we introduce a ratiometric, dual-responsive quantum dot spherical nucleic acid (QD-SNA) probe capable of simultaneously detecting viral- and bacterial-specific markers in vivo. This probe enables real-time monitoring of coinfections, as demonstrated in a mouse model of influenza virus (H1N1) and methicillin-resistant Staphylococcus aureus infection. By providing dynamic, visual insights into the coinfection process, the QD-SNA probe holds significant potential for preclinical drug screening and the diagnosis of respiratory pathogen infections.
{"title":"Ratiometric Dual-Response Quantum Dot Spherical Nucleic Acid for Monitoring Viral Secondary Bacterial Infections","authors":"Ai-Xin Ma, Leping Lin, Qing Zhang, Ming-Yu Zhang, Lin-Han Jiang, Jiaxuan Chen, Shu-Lin Liu, Zhi-Gang Wang, Dai-Wen Pang","doi":"10.1021/acs.analchem.5c00707","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c00707","url":null,"abstract":"Viral–bacterial coinfections present intricate pathologies that exacerbate disease progression and elevate mortality rates. Understanding the dynamic interplay between viruses and bacteria during coinfection is critical for developing effective therapeutic interventions. However, current diagnostic tools primarily rely on static detection methods, limiting their ability to monitor real-time infection dynamics. Here, we introduce a ratiometric, dual-responsive quantum dot spherical nucleic acid (QD-SNA) probe capable of simultaneously detecting viral- and bacterial-specific markers <i>in vivo</i>. This probe enables real-time monitoring of coinfections, as demonstrated in a mouse model of influenza virus (H1N1) and methicillin-resistant <i>Staphylococcus aureus</i> infection. By providing dynamic, visual insights into the coinfection process, the QD-SNA probe holds significant potential for preclinical drug screening and the diagnosis of respiratory pathogen infections.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"66 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853818","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 : 2025-04-20DOI: 10.1021/acs.analchem.5c00633
Patrik Bjärterot, Anna Nilsson, Reza Shariatgorji, Theodosia Vallianatou, Ibrahim Kaya, Per Svenningsson, Lukas Käll, Per E. Andrén
Here, we introduce Met-ID, a graphical user interface software designed to efficiently identify metabolites from MALDI-MSI data sets. Met-ID enables annotation of m/z features from any type of MALDI-MSI experiment, involving either derivatizing or conventional matrices. It utilizes structural information for derivatizing matrices to generate a subset of targets that contain only functional groups specific to the derivatization agent. The software is able to identify multiple derivatization sites on the same molecule, facilitating identification of the derivatized compound. This ability is exemplified by FMP-10, a reactive matrix that assists the covalent charge-tagging of molecules containing phenolic hydroxyl and/or primary or secondary amine groups. Met-ID also permits users to recalibrate data with known m/z ratios, boosting confidence in mass match results. Furthermore, Met-ID includes a database featuring MS2 spectra of numerous chemical standards, consisting of neurotransmitters and metabolites derivatized with FMP-10, alongside peaks for FMP-10 itself, all accessible directly through the software. The MS2 spectral database supports user-uploaded spectra and enables comparison of these spectra with user-provided tissue MS2 spectra for similarity assessment. Although initially installed with basic data, Met-ID is designed to be customizable, encouraging users to tailor the software to their specific needs. While several MSI-oriented software solutions exist, Met-ID combines both MS1 and MS2 functionalities. Developed in alignment with the FAIR Guiding Principles for scientific software, Met-ID is freely available as an open-source tool on GitHub, ensuring wide accessibility and collaboration.
{"title":"Met-ID: An Open-Source Software for Comprehensive Annotation of Multiple On-Tissue Chemical Modifications in MALDI-MSI","authors":"Patrik Bjärterot, Anna Nilsson, Reza Shariatgorji, Theodosia Vallianatou, Ibrahim Kaya, Per Svenningsson, Lukas Käll, Per E. Andrén","doi":"10.1021/acs.analchem.5c00633","DOIUrl":"https://doi.org/10.1021/acs.analchem.5c00633","url":null,"abstract":"Here, we introduce Met-ID, a graphical user interface software designed to efficiently identify metabolites from MALDI-MSI data sets. Met-ID enables annotation of <i>m</i>/<i>z</i> features from any type of MALDI-MSI experiment, involving either derivatizing or conventional matrices. It utilizes structural information for derivatizing matrices to generate a subset of targets that contain only functional groups specific to the derivatization agent. The software is able to identify multiple derivatization sites on the same molecule, facilitating identification of the derivatized compound. This ability is exemplified by FMP-10, a reactive matrix that assists the covalent charge-tagging of molecules containing phenolic hydroxyl and/or primary or secondary amine groups. Met-ID also permits users to recalibrate data with known <i>m</i>/<i>z</i> ratios, boosting confidence in mass match results. Furthermore, Met-ID includes a database featuring MS2 spectra of numerous chemical standards, consisting of neurotransmitters and metabolites derivatized with FMP-10, alongside peaks for FMP-10 itself, all accessible directly through the software. The MS2 spectral database supports user-uploaded spectra and enables comparison of these spectra with user-provided tissue MS2 spectra for similarity assessment. Although initially installed with basic data, Met-ID is designed to be customizable, encouraging users to tailor the software to their specific needs. While several MSI-oriented software solutions exist, Met-ID combines both MS1 and MS2 functionalities. Developed in alignment with the FAIR Guiding Principles for scientific software, Met-ID is freely available as an open-source tool on GitHub, ensuring wide accessibility and collaboration.","PeriodicalId":27,"journal":{"name":"Analytical Chemistry","volume":"5 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853787","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：