Colin Elliott,Aaron Shafer,Shari Forbes,Theresa Stotesbury
Post-mortem interval (PMI) estimation remains a complex yet crucial task in medico-legal death investigations, as accurate and reliable estimates could establish timelines and contextualize physical evidence. Taphonomic studies often use pig carcasses as human analogues, and while they perform well in some entomology experiments, comparative studies have shown interspecies differences in biomolecular degradation during decomposition. Further, few studies use fluorimetry, leaving the degradation of fluorophores understudied in both species. Herein, we integrated PMI analysis into DNA extraction protocols by probing typically discarded cell lysates, enabling multiple analyses from a single sample. Our dataset included human and pig remains: 50 biopsy punches collected from 14 human donors at the Research in Experimental and Social Thanatology (REST) facility in Québec, Canada and 21 biopsy punches from two pigs placed in Oshawa, Canada, with PMIs ranging from 0-1185 days (9.9-11281.7 accumulated degree days; ADD). An excitation-emission matrix was acquired for each lysate and deconvoluted using parallel factor analysis (PARAFAC) to identify individual fluorophores. PARAFAC models revealed similar fluorophores and time-dependent trends in both species. Tryptophan fluorescence decreased over time, while fluorescence between 400-500 nm increased as PMI progressed, attributed to an accumulation of fluorescent oxidation products and advanced glycation end-products.Although partial least squares discriminant analysis demonstrated fluorescence differences between species, principal component analysis did not yield species-specific groupings and displayed common PMI/ADD-related trends for both species. Our findings suggest that interspecies differences are not primarily driven by PMI/ADD, and that pig carcasses are a useful human analogue in taphonomic studies using fluorimetry.
{"title":"The analysis of post-mortem fluorescent signatures in discarded cell lysate from DNA extractions: a comparative study between pig and human remains","authors":"Colin Elliott,Aaron Shafer,Shari Forbes,Theresa Stotesbury","doi":"10.1039/d6an00650g","DOIUrl":"https://doi.org/10.1039/d6an00650g","url":null,"abstract":"Post-mortem interval (PMI) estimation remains a complex yet crucial task in medico-legal death investigations, as accurate and reliable estimates could establish timelines and contextualize physical evidence. Taphonomic studies often use pig carcasses as human analogues, and while they perform well in some entomology experiments, comparative studies have shown interspecies differences in biomolecular degradation during decomposition. Further, few studies use fluorimetry, leaving the degradation of fluorophores understudied in both species. Herein, we integrated PMI analysis into DNA extraction protocols by probing typically discarded cell lysates, enabling multiple analyses from a single sample. Our dataset included human and pig remains: 50 biopsy punches collected from 14 human donors at the Research in Experimental and Social Thanatology (REST) facility in Québec, Canada and 21 biopsy punches from two pigs placed in Oshawa, Canada, with PMIs ranging from 0-1185 days (9.9-11281.7 accumulated degree days; ADD). An excitation-emission matrix was acquired for each lysate and deconvoluted using parallel factor analysis (PARAFAC) to identify individual fluorophores. PARAFAC models revealed similar fluorophores and time-dependent trends in both species. Tryptophan fluorescence decreased over time, while fluorescence between 400-500 nm increased as PMI progressed, attributed to an accumulation of fluorescent oxidation products and advanced glycation end-products.Although partial least squares discriminant analysis demonstrated fluorescence differences between species, principal component analysis did not yield species-specific groupings and displayed common PMI/ADD-related trends for both species. Our findings suggest that interspecies differences are not primarily driven by PMI/ADD, and that pig carcasses are a useful human analogue in taphonomic studies using fluorimetry.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"269 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atomic force microscopy–infrared (AFM-IR) spectroscopy enables nanoscale chemical characterization, but apparent peak shifts in supported thin films can combine genuine film-structure evolution with thickness-dependent measurement response. Here, replicated AFM-IR spectra of TEOS-derived silica films with nominal thicknesses of 10 nm, 50 nm, 100 nm and 200 nm were benchmarked against thickness-matched transmission Fourier-transform infrared (FT-IR) spectra. Film thicknesses were determined by X-ray reflectivity. The principal Si–O–Si band shifted to lower wavenumber with increasing thickness in both methods, but the total shift was approximately 23 cm−1 in AFM-IR and only 6 cm−1 in FT-IR. The AFM-IR thickness dependence therefore substantially exceeded the trend shared by the two methods, indicating additional technique-specific spectral weighting. A high-wavenumber area fraction defined without component fitting showed the largest excess in AFM-IR relative to FT-IR for the 10 nm film, which also exhibited the largest between-method peak-position difference. The AFM-IR/FTIR area-fraction ratio decreased from 2.07 at 10 nm to 1.06–1.08 at 100 nm to 200 nm, and this thickness trend was retained when the baseline and integration windows were varied. FT-IR/XRR-derived SiOH number-density trends were also consistent with an AFM-IR-resolved SiOH-related O–H feature near 3620 cm−1 in the 50 nm, 100 nm and 200 nm films. Thickness-matched far-field benchmarking combined with model-independent line-shape analysis provides a practical framework for evaluating the measurement response embedded in AFM-IR peak changes before attributing them to nanoscale chemical heterogeneity.
{"title":"Thickness-matched FT-IR benchmarking reveals spectral bias in AFM-IR measurements of supported silica films","authors":"Tatsuhiro Nagasaka,Keiko Inoue,Aki Suzuki,Yusaku Tanahashi,Hirofumi Seki","doi":"10.1039/d6an01014h","DOIUrl":"https://doi.org/10.1039/d6an01014h","url":null,"abstract":"Atomic force microscopy–infrared (AFM-IR) spectroscopy enables nanoscale chemical characterization, but apparent peak shifts in supported thin films can combine genuine film-structure evolution with thickness-dependent measurement response. Here, replicated AFM-IR spectra of TEOS-derived silica films with nominal thicknesses of 10 nm, 50 nm, 100 nm and 200 nm were benchmarked against thickness-matched transmission Fourier-transform infrared (FT-IR) spectra. Film thicknesses were determined by X-ray reflectivity. The principal Si–O–Si band shifted to lower wavenumber with increasing thickness in both methods, but the total shift was approximately 23 cm−1 in AFM-IR and only 6 cm−1 in FT-IR. The AFM-IR thickness dependence therefore substantially exceeded the trend shared by the two methods, indicating additional technique-specific spectral weighting. A high-wavenumber area fraction defined without component fitting showed the largest excess in AFM-IR relative to FT-IR for the 10 nm film, which also exhibited the largest between-method peak-position difference. The AFM-IR/FTIR area-fraction ratio decreased from 2.07 at 10 nm to 1.06–1.08 at 100 nm to 200 nm, and this thickness trend was retained when the baseline and integration windows were varied. FT-IR/XRR-derived SiOH number-density trends were also consistent with an AFM-IR-resolved SiOH-related O–H feature near 3620 cm−1 in the 50 nm, 100 nm and 200 nm films. Thickness-matched far-field benchmarking combined with model-independent line-shape analysis provides a practical framework for evaluating the measurement response embedded in AFM-IR peak changes before attributing them to nanoscale chemical heterogeneity.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"11 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gmelina asiatica L. plays a significant role in traditional medicine, with diverse applications in the Ayurvedic and Siddha systems and multiple pharmacological activities. However, no validated analytical method has been reported for its standardization and quality control through the quantification of its major phytoconstituent, despite its importance for pharmaceutical applications. Therefore, a sensitive and validated method for its standardization is required. In this context, liquid chromatography-mass spectrometry is one of the most suitable analytical techniques for this purpose. In this study, ultra-performance liquid chromatography-Q-Exactive-Orbitrap-mass spectrometry (UHPLC-Q-Exactive-Orbitrap-MS) and ultra-performance liquid chromatography-triple quadrupole-mass spectrometry (UHPLC-TQ-MS/MS) were employed to identify the marker compound of Gmelina asiatica and subsequently quantify it using a validated method. UHPLC-Q-Exactive-Orbitrap-MS revealed 699 metabolites after applying filtration criteria. The marker compound was identified as verbascoside/isoverbascoside (m/z 623.165 [M − H]−) and subsequently distinguished by UHPLC-TQ-MS/MS using selected reaction monitoring (SRM) transitions and retention time in comparison with an authentic reference standard, confirming its identity as verbascoside. The developed UHPLC-TQ-MS/MS method was validated and demonstrated excellent selectivity, precision, accuracy, and linearity (R2 ≥ 0.9989) over the range of 0.5–100 µg L−1, with limits of detection and quantification of 0.005 and 0.016 µg L−1, respectively. The validated method was successfully applied to quantify verbascoside in Gmelina asiatica extract, yielding 48.18 ± 3.67 mg g−1 extract (4.82%, w/w). The relatively high abundance of verbascoside demonstrates its suitability as a marker compound for the standardization and quality control of Gmelina asiatica and supports its reported pharmacological activities. This study establishes a reliable and validated UHPLC-TQ-MS/MS method for verbascoside-based standardization of Gmelina asiatica.
{"title":"Untargeted identification and targeted quantification of the marker compound in L. using UHPLC-Q Exactive Orbitrap MS and validated UHPLC-TQ-MS/MS methods","authors":"Rasha Ksirri,Siva Hemalatha","doi":"10.1039/d6an01035k","DOIUrl":"https://doi.org/10.1039/d6an01035k","url":null,"abstract":"Gmelina asiatica L. plays a significant role in traditional medicine, with diverse applications in the Ayurvedic and Siddha systems and multiple pharmacological activities. However, no validated analytical method has been reported for its standardization and quality control through the quantification of its major phytoconstituent, despite its importance for pharmaceutical applications. Therefore, a sensitive and validated method for its standardization is required. In this context, liquid chromatography-mass spectrometry is one of the most suitable analytical techniques for this purpose. In this study, ultra-performance liquid chromatography-Q-Exactive-Orbitrap-mass spectrometry (UHPLC-Q-Exactive-Orbitrap-MS) and ultra-performance liquid chromatography-triple quadrupole-mass spectrometry (UHPLC-TQ-MS/MS) were employed to identify the marker compound of Gmelina asiatica and subsequently quantify it using a validated method. UHPLC-Q-Exactive-Orbitrap-MS revealed 699 metabolites after applying filtration criteria. The marker compound was identified as verbascoside/isoverbascoside (m/z 623.165 [M − H]−) and subsequently distinguished by UHPLC-TQ-MS/MS using selected reaction monitoring (SRM) transitions and retention time in comparison with an authentic reference standard, confirming its identity as verbascoside. The developed UHPLC-TQ-MS/MS method was validated and demonstrated excellent selectivity, precision, accuracy, and linearity (R2 ≥ 0.9989) over the range of 0.5–100 µg L−1, with limits of detection and quantification of 0.005 and 0.016 µg L−1, respectively. The validated method was successfully applied to quantify verbascoside in Gmelina asiatica extract, yielding 48.18 ± 3.67 mg g−1 extract (4.82%, w/w). The relatively high abundance of verbascoside demonstrates its suitability as a marker compound for the standardization and quality control of Gmelina asiatica and supports its reported pharmacological activities. This study establishes a reliable and validated UHPLC-TQ-MS/MS method for verbascoside-based standardization of Gmelina asiatica.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"30 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Thomas Knecht,Maxwell J. Unger,Alison R. H. Narayan,Robert T. Kennedy
Droplet microfluidics has become a versatile tool for high-throughput phenotypic analysis of cells, employed in enzyme engineering, drug screening, and antibiotic assays. An important metric in such bioanalyses is the optical density (OD600) of the culture, but current methods for measuring OD600 within cultured droplets are limited. Herein, we present a machine-vision method for the measurement of OD600 between 0.1 and 4.3 in flowing microdroplets from 0.5–50 nL in volume. This system can make real-time decisions based on cell density and volume measurements and was demonstrated to remove vacant droplets from an emulsion by dielectrophoretic sorting at up to 10 droplets per s based on cell density with an error rate below 10%. We show that droplets can also be subjected to subsequent on-line analysis such as mass spectrometry (MS) and their growth levels correlated to metabolite abundances. We show that growth level is correlated with lysine abundance in droplets incubated with engineered E. coli cells.
{"title":"Machine vision-enabled OD measurement and mass spectrometric determination of metabolites of microbial cell-containing microfluidic droplets in real-time","authors":"G. Thomas Knecht,Maxwell J. Unger,Alison R. H. Narayan,Robert T. Kennedy","doi":"10.1039/d6an00623j","DOIUrl":"https://doi.org/10.1039/d6an00623j","url":null,"abstract":"Droplet microfluidics has become a versatile tool for high-throughput phenotypic analysis of cells, employed in enzyme engineering, drug screening, and antibiotic assays. An important metric in such bioanalyses is the optical density (OD600) of the culture, but current methods for measuring OD600 within cultured droplets are limited. Herein, we present a machine-vision method for the measurement of OD600 between 0.1 and 4.3 in flowing microdroplets from 0.5–50 nL in volume. This system can make real-time decisions based on cell density and volume measurements and was demonstrated to remove vacant droplets from an emulsion by dielectrophoretic sorting at up to 10 droplets per s based on cell density with an error rate below 10%. We show that droplets can also be subjected to subsequent on-line analysis such as mass spectrometry (MS) and their growth levels correlated to metabolite abundances. We show that growth level is correlated with lysine abundance in droplets incubated with engineered E. coli cells.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"101 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polypropylene glycol 1000 (PPG1000) is a hydrophilic polymer widely used in pharmaceuticals and industry, but quantifying it in complex biological samples remains challenging. This study develops and validates a sensitive UPLC-MS/MS method for PPG1000 measurement in zebrafish tissues. The method combines micro-solid-phase extraction (μ-SPE) cleanup with a 2.5 min chromatographic run and MS³ detection for PPG1000-equivalent quantification in zebrafish tissues. We systematically compared three mass spectrometric acquisition modes: multiple reaction monitoring (MRM), MS³, and in-source collision-induced dissociation (CID). The ammonium adduct [M+NH₄]⁺ of the 15-mer oligomer (m/z 906.6) served as the precursor ion. MS³ using a linear ion trap (m/z 906.6 → 175.1 → 117.1) delivered the highest signal intensity (3.6×10⁶ cps), approximately 3.3-fold and 40-fold higher than MRM and CID respectively. Integrating μ-SPE further improved method performance over conventional protein precipitation. The method showed excellent linearity (100 to 10000 ng/mL, r > 0.997) and was applied to zebrafish tissue distribution after aqueous exposure to 200 μg/mL PPG1000. All three tissues (gill, liver, brain) exhibited increasing concentrations from 2 to 4 h, with gill showing the highest accumulation. Detectable brain levels suggest partial blood brain barrier penetration. This work provides the first systematic comparison of MRM, MS³, and in-source CID for PPG quantification, establishing a sensitive analytical platform with complementary greenness and practical applicability assessments using AGREE, AGSA, CACI, and GEMAM, for polymer bioanalysis in complex matrices.
{"title":"MS³ acquisition and μ-SPE cleanup enable sensitive quantification of PPG1000 in zebrafish tissues: Systematic comparison with MRM and in-source CID strategies","authors":"Jiarui Zhang,Zichang Tian,Jinqing Wu,Jiale Liu,Xinyue Zhou,Yue Deng,Shuang Feng,Jing Peng,Lei Yin,Linquan Li","doi":"10.1039/d6an00734a","DOIUrl":"https://doi.org/10.1039/d6an00734a","url":null,"abstract":"Polypropylene glycol 1000 (PPG1000) is a hydrophilic polymer widely used in pharmaceuticals and industry, but quantifying it in complex biological samples remains challenging. This study develops and validates a sensitive UPLC-MS/MS method for PPG1000 measurement in zebrafish tissues. The method combines micro-solid-phase extraction (μ-SPE) cleanup with a 2.5 min chromatographic run and MS³ detection for PPG1000-equivalent quantification in zebrafish tissues. We systematically compared three mass spectrometric acquisition modes: multiple reaction monitoring (MRM), MS³, and in-source collision-induced dissociation (CID). The ammonium adduct [M+NH₄]⁺ of the 15-mer oligomer (m/z 906.6) served as the precursor ion. MS³ using a linear ion trap (m/z 906.6 → 175.1 → 117.1) delivered the highest signal intensity (3.6×10⁶ cps), approximately 3.3-fold and 40-fold higher than MRM and CID respectively. Integrating μ-SPE further improved method performance over conventional protein precipitation. The method showed excellent linearity (100 to 10000 ng/mL, r > 0.997) and was applied to zebrafish tissue distribution after aqueous exposure to 200 μg/mL PPG1000. All three tissues (gill, liver, brain) exhibited increasing concentrations from 2 to 4 h, with gill showing the highest accumulation. Detectable brain levels suggest partial blood brain barrier penetration. This work provides the first systematic comparison of MRM, MS³, and in-source CID for PPG quantification, establishing a sensitive analytical platform with complementary greenness and practical applicability assessments using AGREE, AGSA, CACI, and GEMAM, for polymer bioanalysis in complex matrices.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"226 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bacteraemia is a life-threatening infection associated with substantial morbidity and mortality. Current diagnosis relies on blood culture followed by culture-based identification and antimicrobial susceptibility testing, which remain the clinical gold standard but require prolonged turnaround times. Isothermal amplification technologies such as loop-mediated isothermal amplification (LAMP) offer a rapid, cost-effective, and accessible alternative for pathogen identification and antimicrobial resistance detection directly from positive blood cultures, particularly in resource-limited settings. However, their widespread implementation remains constrained by sample preparation requirements and limited multiplexing capabilities. To address these challenges, we developed ALADIM (Accessible and integrated LAMP Analysis for multiplex Detection of Infectious agents in Microfluidics), an integrated microfluidic platform combining bacterial DNA extraction, multiplex on-chip LAMP amplification, and instrument-free amplicon detection by lateral flow immunoassay (LFIA). The complete workflow can be performed in less than two hours, compared with the 24-48 h typically required for conventional diagnostic methods. As a proof of concept, the system was designed to detect E. coli, the most frequently reported pathogen in bacteraemia, together with two clinically relevant antimicrobial resistance determinants, blaCTX-M-15 and blaOXA-48, as well as an internal positive control. The multiplex assay was first evaluated using 14 bacterial strains cultured in LB medium. Performance of the on-chip workflow was comparable to that of the reference method consisting of conventional tube-based LAMP followed by LFIA detection, achieving 100% sensitivity and >84% specificity for malF and blaOXA-48, and 68% sensitivity with 83% specificity for blaCTX-M-15. The complete ALADIM workflow was subsequently assessed using overnight positive blood cultures generated from 15 PCR-characterised strains, corresponding to 61 independent experiments encompassing sample preparation, DNA amplification, and LFIA readout. In this more challenging matrix, specificity remained above 77% for all targets. Sensitivity exceeded 94% for malF and blaOXA-48, whereas detection of blaCTX-M-15 showed lower sensitivity (56%). A comparable reduction in sensitivity was also observed with the reference in-tube method (>68%), underscoring the analytical challenges associated with direct analysis of blood culture-derived samples. Overall, this study demonstrates the feasibility of integrating sample preparation, multiplex nucleic acid amplification, microfluidic handling, and lateral-flow-based detection within a single user-friendly platform. While further optimization is required to improve performance in complex matrices, increase analytical sensitivity, and expand multiplexing capabilities, ALADIM provides a promising foundation for the development of accessible molecular diagnostics for bloodstream infect
{"title":"Simplified bacterial identification and antimicrobial resistance detection in bacteraemia by on-chip multiplexed LAMP from blood cultures","authors":"Capucine Treille,Lilas Pommiès,Xenia Garcia Velasquez,Hervé Volland,Karla Perez-Toralla,Hervé Boutal","doi":"10.1039/d5an01310k","DOIUrl":"https://doi.org/10.1039/d5an01310k","url":null,"abstract":"Bacteraemia is a life-threatening infection associated with substantial morbidity and mortality. Current diagnosis relies on blood culture followed by culture-based identification and antimicrobial susceptibility testing, which remain the clinical gold standard but require prolonged turnaround times. Isothermal amplification technologies such as loop-mediated isothermal amplification (LAMP) offer a rapid, cost-effective, and accessible alternative for pathogen identification and antimicrobial resistance detection directly from positive blood cultures, particularly in resource-limited settings. However, their widespread implementation remains constrained by sample preparation requirements and limited multiplexing capabilities. To address these challenges, we developed ALADIM (Accessible and integrated LAMP Analysis for multiplex Detection of Infectious agents in Microfluidics), an integrated microfluidic platform combining bacterial DNA extraction, multiplex on-chip LAMP amplification, and instrument-free amplicon detection by lateral flow immunoassay (LFIA). The complete workflow can be performed in less than two hours, compared with the 24-48 h typically required for conventional diagnostic methods. As a proof of concept, the system was designed to detect E. coli, the most frequently reported pathogen in bacteraemia, together with two clinically relevant antimicrobial resistance determinants, blaCTX-M-15 and blaOXA-48, as well as an internal positive control. The multiplex assay was first evaluated using 14 bacterial strains cultured in LB medium. Performance of the on-chip workflow was comparable to that of the reference method consisting of conventional tube-based LAMP followed by LFIA detection, achieving 100% sensitivity and >84% specificity for malF and blaOXA-48, and 68% sensitivity with 83% specificity for blaCTX-M-15. The complete ALADIM workflow was subsequently assessed using overnight positive blood cultures generated from 15 PCR-characterised strains, corresponding to 61 independent experiments encompassing sample preparation, DNA amplification, and LFIA readout. In this more challenging matrix, specificity remained above 77% for all targets. Sensitivity exceeded 94% for malF and blaOXA-48, whereas detection of blaCTX-M-15 showed lower sensitivity (56%). A comparable reduction in sensitivity was also observed with the reference in-tube method (>68%), underscoring the analytical challenges associated with direct analysis of blood culture-derived samples. Overall, this study demonstrates the feasibility of integrating sample preparation, multiplex nucleic acid amplification, microfluidic handling, and lateral-flow-based detection within a single user-friendly platform. While further optimization is required to improve performance in complex matrices, increase analytical sensitivity, and expand multiplexing capabilities, ALADIM provides a promising foundation for the development of accessible molecular diagnostics for bloodstream infect","PeriodicalId":63,"journal":{"name":"Analyst","volume":"7 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149013577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kana Matsuoka,Masahiro Ando,Takuji Nakashima,Haruko Takeyama
Liquid chromatography (LC) has been the gold standard for analyzing complex biological samples, yet conventional detection methods present analytical challenges. Mass spectrometry requires expensive instrumentation and struggles with structural isomers. UV and fluorescence detection necessitate derivatization for compounds lacking chromophores, extending analysis time and potentially altering labile compounds or masking structural modifications. Raman spectroscopy offers fundamentally different detection principles that could address these challenges by directly probing molecular vibrations to provide structural information independent of UV absorption. However, the primary obstacle to LC-Raman implementation has been Raman spectroscopy's inherently weak scattering signal. This study addresses these fundamental challenges through a simple yet effective approach using a newly developed system combining post-column spotting with solvent evaporation. By transforming dilute liquid samples into concentrated solid deposits, this method dramatically enhances Raman signals while simultaneously eliminating solvent interference. The approach was applied to comprehensive amino acid analysis, which is essential for evaluating complex biological matrices. The LC-Raman system achieved remarkable sensitivity with signal-to-noise ratios above 10 at 20 ng injection level, demonstrating that solvent evaporation and solid-state concentration effectively overcome traditional sensitivity limitations. All 20 proteinogenic amino acids were detected without derivatization regardless of chromophore presence. Beyond sensitivity improvements, the system provides direct structural identification through vibrational spectroscopy. Lysine and its post-translational modifications (Nε-acetyl-lysine and Nε,Nε,Nε-trimethyllysine) were clearly discriminated through diagnostic vibrational bands. This demonstrates a distinct advantage of the Raman-based approach: direct molecular identification through intrinsic vibrational fingerprints without requiring fragmentation or derivatization, providing complementary information to existing methods. Analysis of DMEM cell culture medium identified eight major amino acids, and multivariate curve resolution successfully extracted pure component spectra for co-eluting leucine, isoleucine, and glucose, adding a chemical dimension to chromatographic separation. Furthermore, phenylalanine and glutamine in the cell culture medium were determined via LC-Raman spectroscopy. This study establishes LC-Raman spectroscopy as a powerful analytical tool that successfully addresses historical sensitivity limitations while preserving unique molecular identification capabilities. The approach's applicability extends beyond amino acids to any LC-amenable compounds with sufficient Raman activity, opening new possibilities for pharmaceutical, clinical, and biotechnology applications where structural specificity and label-free analysis are essential.
{"title":"Sensitive and derivatization-free amino acid analysis using liquid chromatography-Raman spectroscopy","authors":"Kana Matsuoka,Masahiro Ando,Takuji Nakashima,Haruko Takeyama","doi":"10.1039/d6an00841k","DOIUrl":"https://doi.org/10.1039/d6an00841k","url":null,"abstract":" Liquid chromatography (LC) has been the gold standard for analyzing complex biological samples, yet conventional detection methods present analytical challenges. Mass spectrometry requires expensive instrumentation and struggles with structural isomers. UV and fluorescence detection necessitate derivatization for compounds lacking chromophores, extending analysis time and potentially altering labile compounds or masking structural modifications. Raman spectroscopy offers fundamentally different detection principles that could address these challenges by directly probing molecular vibrations to provide structural information independent of UV absorption. However, the primary obstacle to LC-Raman implementation has been Raman spectroscopy's inherently weak scattering signal. This study addresses these fundamental challenges through a simple yet effective approach using a newly developed system combining post-column spotting with solvent evaporation. By transforming dilute liquid samples into concentrated solid deposits, this method dramatically enhances Raman signals while simultaneously eliminating solvent interference. The approach was applied to comprehensive amino acid analysis, which is essential for evaluating complex biological matrices. The LC-Raman system achieved remarkable sensitivity with signal-to-noise ratios above 10 at 20 ng injection level, demonstrating that solvent evaporation and solid-state concentration effectively overcome traditional sensitivity limitations. All 20 proteinogenic amino acids were detected without derivatization regardless of chromophore presence. Beyond sensitivity improvements, the system provides direct structural identification through vibrational spectroscopy. Lysine and its post-translational modifications (Nε-acetyl-lysine and Nε,Nε,Nε-trimethyllysine) were clearly discriminated through diagnostic vibrational bands. This demonstrates a distinct advantage of the Raman-based approach: direct molecular identification through intrinsic vibrational fingerprints without requiring fragmentation or derivatization, providing complementary information to existing methods. Analysis of DMEM cell culture medium identified eight major amino acids, and multivariate curve resolution successfully extracted pure component spectra for co-eluting leucine, isoleucine, and glucose, adding a chemical dimension to chromatographic separation. Furthermore, phenylalanine and glutamine in the cell culture medium were determined via LC-Raman spectroscopy. This study establishes LC-Raman spectroscopy as a powerful analytical tool that successfully addresses historical sensitivity limitations while preserving unique molecular identification capabilities. The approach's applicability extends beyond amino acids to any LC-amenable compounds with sufficient Raman activity, opening new possibilities for pharmaceutical, clinical, and biotechnology applications where structural specificity and label-free analysis are essential.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"47 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149013578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meng Deng,Hao Guo,Zeyun Yang,Ruixue Yan,Jianpeng Ma,Wenting Niu,Yujiao Kang,Mingyue Wang,Wu Yang
Rutin (RT), a crucial flavonoid compound, exhibits significant physiological activities and medicinal value through its anti-tumor, anti-oxidation, and anti-inflammation effects, and cardiovascular protection. It is of great significance to develop an efficient and sensitive detection method for rutin. To achieve sensitive and rapid detection of rutin, this study constructs a novel composite-material electrochemical sensing platform based on a highly crystalline covalent organic framework (A-COF). The A-COF@NH2-MWCNT/GCE electrochemical sensor was successfully fabricated by preparing an in situ grown A-COF@NH2-MWCNT composite material to modify a glassy carbon electrode (GCE). Under the optimized experimental conditions, the electrochemical response of the sensor to rutin was investigated using the CV method and the DPV method. The results indicate that the constructed sensor exhibits satisfactory electrochemical characteristics, with a detection limit of 0.01 μM (S/N = 3) and a linear range of 0.2–170 μM. It also demonstrates good repeatability, reproducibility, stability, and anti-interference ability. The sensor was applied to detect rutin content in actual samples (human serum, urine, rutin tablets and buckwheat), and the results were accurate and reliable, with high recovery rates. This study offers a novel, simple and efficient electrochemical detection method for the trace analysis of rutin.
{"title":"A novel electrochemical sensing platform based on highly crystalline covalent organic frameworks for the sensitive detection of rutin","authors":"Meng Deng,Hao Guo,Zeyun Yang,Ruixue Yan,Jianpeng Ma,Wenting Niu,Yujiao Kang,Mingyue Wang,Wu Yang","doi":"10.1039/d6an00698a","DOIUrl":"https://doi.org/10.1039/d6an00698a","url":null,"abstract":"Rutin (RT), a crucial flavonoid compound, exhibits significant physiological activities and medicinal value through its anti-tumor, anti-oxidation, and anti-inflammation effects, and cardiovascular protection. It is of great significance to develop an efficient and sensitive detection method for rutin. To achieve sensitive and rapid detection of rutin, this study constructs a novel composite-material electrochemical sensing platform based on a highly crystalline covalent organic framework (A-COF). The A-COF@NH2-MWCNT/GCE electrochemical sensor was successfully fabricated by preparing an in situ grown A-COF@NH2-MWCNT composite material to modify a glassy carbon electrode (GCE). Under the optimized experimental conditions, the electrochemical response of the sensor to rutin was investigated using the CV method and the DPV method. The results indicate that the constructed sensor exhibits satisfactory electrochemical characteristics, with a detection limit of 0.01 μM (S/N = 3) and a linear range of 0.2–170 μM. It also demonstrates good repeatability, reproducibility, stability, and anti-interference ability. The sensor was applied to detect rutin content in actual samples (human serum, urine, rutin tablets and buckwheat), and the results were accurate and reliable, with high recovery rates. This study offers a novel, simple and efficient electrochemical detection method for the trace analysis of rutin.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"32 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149010187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liu Zhao,Haiyun Yang,Xin Zhu,Wenhong Che,Qiuyu Meng,Lu Yang,Chunmei Yang
Computed tomography (CT) represents one of the most widely utilized and clinically effective imaging techniques for gastrointestinal diseases. Specifically, spectral CT, as an advanced evolution of conventional CT, has significantly improved diagnostic accuracy. The creation of high-performance and biocompatible contrast agents is essential for achieving superior visualization of the gastrointestinal tract and facilitating accurate disease identification. Recent studies reveal that small molecule- and nanoparticle-based contrast agents with high atomic number elements demonstrate significant promise in gastrointestinal diagnostics via spectral CT imaging. Therefore, this review systematically discusses the synthesis, characteristics and advantages of small molecule- and nanoparticle-based contrast agents, with emphasis on their utility in gastrointestinal imaging, disease diagnosis, and therapeutic interventions. Furthermore, the limitations and future directions of current contrast agents are also evaluated, offering a foundation for the design of novel gastrointestinal spectral CT contrast agents.
{"title":"Recent advances in spectral CT contrast agents for gastrointestinal tract imaging","authors":"Liu Zhao,Haiyun Yang,Xin Zhu,Wenhong Che,Qiuyu Meng,Lu Yang,Chunmei Yang","doi":"10.1039/d6an00572a","DOIUrl":"https://doi.org/10.1039/d6an00572a","url":null,"abstract":"Computed tomography (CT) represents one of the most widely utilized and clinically effective imaging techniques for gastrointestinal diseases. Specifically, spectral CT, as an advanced evolution of conventional CT, has significantly improved diagnostic accuracy. The creation of high-performance and biocompatible contrast agents is essential for achieving superior visualization of the gastrointestinal tract and facilitating accurate disease identification. Recent studies reveal that small molecule- and nanoparticle-based contrast agents with high atomic number elements demonstrate significant promise in gastrointestinal diagnostics via spectral CT imaging. Therefore, this review systematically discusses the synthesis, characteristics and advantages of small molecule- and nanoparticle-based contrast agents, with emphasis on their utility in gastrointestinal imaging, disease diagnosis, and therapeutic interventions. Furthermore, the limitations and future directions of current contrast agents are also evaluated, offering a foundation for the design of novel gastrointestinal spectral CT contrast agents.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"15 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149010188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patricia Gimenez Barrera,Anne Michelin,Aurélie Tournié,Kaoutar El Haloui,Tsveta Miteva,Emeline Pouyet
Neural networks are increasingly used in conservation science to exploit hyperspectral imaging (HSI) datasets. The literature includes a wide range of models with different architectures and hyperparameters available to the community. Yet, defining the optimal configurations of such parameters for new datasets is not straightforward. This work focuses on state-of-the-art optimization strategies to ensure that the best performance of the models is achieved, offering new opportunities for improving the predictive capacity of the model on unseen data. In particular, a synthetic mixture dataset is designed to train two widely-used neural network models: a 1D-CNN and a fully connected deep neural network (FC-DNN). The two models with architecture and hyperparameters taken directly from the literature are compared with optimized models using Bayesian approaches that combine Neural Architecture Search (NAS) and hyperparameter optimization (HPO). Full optimization of both the architecture and the hyperparameters of the neural network have proven to improve significantly the pigment classification accuracy, enabling more reliable pigment mapping from reflectance imaging spectroscopy (RIS) data. Optimized 1D-CNN and FC-DNN present similar capabilities for multilabel pigment classification of artistic materials, as shown through a representative case study on medieval illumination mock-ups.
{"title":"Deep neural network optimization for pigment classification: a case study on representative medieval illumination mock-ups","authors":"Patricia Gimenez Barrera,Anne Michelin,Aurélie Tournié,Kaoutar El Haloui,Tsveta Miteva,Emeline Pouyet","doi":"10.1039/d6an00787b","DOIUrl":"https://doi.org/10.1039/d6an00787b","url":null,"abstract":"Neural networks are increasingly used in conservation science to exploit hyperspectral imaging (HSI) datasets. The literature includes a wide range of models with different architectures and hyperparameters available to the community. Yet, defining the optimal configurations of such parameters for new datasets is not straightforward. This work focuses on state-of-the-art optimization strategies to ensure that the best performance of the models is achieved, offering new opportunities for improving the predictive capacity of the model on unseen data. In particular, a synthetic mixture dataset is designed to train two widely-used neural network models: a 1D-CNN and a fully connected deep neural network (FC-DNN). The two models with architecture and hyperparameters taken directly from the literature are compared with optimized models using Bayesian approaches that combine Neural Architecture Search (NAS) and hyperparameter optimization (HPO). Full optimization of both the architecture and the hyperparameters of the neural network have proven to improve significantly the pigment classification accuracy, enabling more reliable pigment mapping from reflectance imaging spectroscopy (RIS) data. Optimized 1D-CNN and FC-DNN present similar capabilities for multilabel pigment classification of artistic materials, as shown through a representative case study on medieval illumination mock-ups.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"13 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148993853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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