Analytical Methods最新文献

{"title":"An antibody-functionalized N-CQD-based \"Off-On\" fluorescent probe for serum C3M detection: a proof-of-concept study toward postoperative joint rehabilitation assessment.","authors":"Shang Wu, Kai Feng, Yu Zhang, Yi Zhou, Letao Jiang, Jianwei Du, Jing Wang","doi":"10.1039/d6ay01751g","DOIUrl":"https://doi.org/10.1039/d6ay01751g","url":null,"abstract":"<p><p>Monitoring postoperative rehabilitation progress following joint surgery remains a clinical challenge due to the lack of rapid, quantitative, and dynamic biomarkers. Here, we developed an \"Off-On\" fluorescent sensing system based on antibody-functionalized nitrogen-doped carbon quantum dots (N-CQDs) for sensitive detection of serum C3M, a type II collagen degradation fragment, as a preliminary approach toward postoperative joint rehabilitation assessment. The N-CQDs were synthesized <i>via</i> a one-step hydrothermal method using citric acid and urea as precursors, with an emission maximum at 460 nm. Anti-C3M monoclonal antibodies were covalently conjugated to the N-CQDs surface <i>via</i> EDC/NHS chemistry. The fluorescence of the resulting Ab-N-CQDs probe was quenched by BHQ-1-labeled specific peptides through FRET, forming the \"Off\" state. Upon addition of target C3M, competitive antigen-antibody binding displaced the quencher-labeled peptide, restoring fluorescence (\"On\" state). The sensor showed a linear range of 10-100 ng mL^-1, a detection limit of 0.05 ng mL^-1, and good selectivity. Preliminary method comparison with a commercial C3M ELISA using all available serum samples (<i>n</i> = 9) showed a strong correlation (Spearman <i>ρ</i> = 0.95, <i>p</i> < 0.001) and a mean bias of -0.44 ng mL^-1 by Bland-Altman analysis. In a pilot proof-of-concept study with 9 participants (4 healthy controls and 5 patients), C3M levels were significantly elevated in patients, with distinct temporal profiles at postoperative days 1, 3, 7, and 14. This sensitive and simple assay provides a promising approach for serum C3M detection and may be potentially adaptable to point-of-care testing in the future, although the current method still requires laboratory fluorescence instrumentation and a 40-min incubation. However, the small sample size precludes any conclusion regarding rehabilitation assessment; larger studies with standardized rehabilitation endpoints are required.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339911","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}

{"title":"A barcode-enabled distance-based paper sensor using silver chloranilate for semi-quantitative determination of chloride in various water sources.","authors":"Rattapol Meelapsom, Rakfan Phothi, Thunwarat Sudchada, Thanaporn Songsaard, Niyada Khunkhong, Nutthaporn Malahom, Yanawut Manmana, Daniel Citterio, Purim Jarujamrus","doi":"10.1039/d6ay01764a","DOIUrl":"https://doi.org/10.1039/d6ay01764a","url":null,"abstract":"<p><p>Chloride monitoring is important for drinking-water quality assessment, corrosion control, and environmental analysis. In this work, a dual-mode distance-based paper analytical device (d-PAD) was developed for chloride determination using silver chloranilate as a chromate-free colorimetric indicator. An <i>in situ</i> silver chloranilate sensing layer was prepared on the paper substrate through sequential deposition of silver nitrate and chloranilic acid. In the presence of chloride ions, AgCl formation was accompanied by the release of violet chloranilate species, producing a concentration-dependent migration zone along the paper channel. The device enabled quantitative determination based on migration distance and complementary semi-quantitative classification using a six-character Code 39 barcode mask and a smartphone barcode-scanning application. Under the optimized conditions, the PEG-functionalized d-PAD exhibited a linear working range of 100-800 mg L^-1 chloride with a coefficient of determination of <i>r</i>² = 0.9980. PEG treatment provided a more clearly defined migration front with improved contrast against the brown background. The barcode-assisted readout classified chloride concentrations into five intervals: <100, 100 to <250, 250 to <400, 400 to <600, and ≥600 mg L^-1. The method exhibited adequate selectivity for the coexisting ions evaluated and yielded recoveries of 98.98-105.39% with RSD values not exceeding 5% in spiked water samples. Results obtained using the d-PAD were comparable to those obtained by Mohr titration, with relative errors ranging from 0.64% to 4.31%. Overall, the combined distance-based and barcode-assisted readouts provide a simple and portable platform for point-of-need chloride analysis in water samples.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339900","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}

{"title":"R for analytical chemistry: a powerful, free and transparent statistical toolkit.","authors":"Analytical Methods Committee Amctb No","doi":"10.1039/d6ay90133f","DOIUrl":"https://doi.org/10.1039/d6ay90133f","url":null,"abstract":"<p><p>R is a free, open-source programming language for statistical computing and graphics, first released in 1995. It has grown into one of the world's most widely used data analysis platforms, with a community of millions of users across science, industry and government. For analytical chemists, R offers a rich set of tools covering calibration, multivariate analysis, chemometrics, spectroscopic data handling and experimental design. Crucially, R promotes reproducible science - every step of an analysis is captured in a script that can be re-run, audited and shared, making calculations fully transparent. This Technical Brief introduces the language to those unfamiliar with it, highlights the most relevant tools for analytical chemistry and demonstrates their use through short practical examples.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339912","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}

{"title":"Dual-channel surface-enhanced Raman immunoassay for simultaneous determination of atrial-fibrillation-associated NT-proBNP and high-sensitivity cardiac troponin I in artificial serum.","authors":"Lijun Qin, Yanhong Mou, Yan Guo, Zhengke Ma","doi":"10.1039/d6ay02032a","DOIUrl":"https://doi.org/10.1039/d6ay02032a","url":null,"abstract":"<p><p>Atrial fibrillation is associated with myocardial wall stress and low-grade injury, yet parallel measurement of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin I (hs-cTnI) generally requires separate immunoassays. We developed a single-chamber, dual-channel surface-enhanced Raman scattering (SERS) immunoassay that combines antibody-functionalised magnetic capture beads with Au@Ag nanotags encoded by 4-mercaptobenzonitrile at 2227 cm^-1 and 4-mercaptobenzoic acid at 1077 cm^-1. A 9 × 9 full-factorial calibration design spanning 0-10 000 pg per mL NT-proBNP and 0-500 pg per mL hs-cTnI was executed across three independently prepared tag lots. Ten spatial spectra were aggregated at the sample level, preprocessed and quantified by a batch-grouped partial least-squares model. Limits of detection were 6.30 pg mL^-1 for NT-proBNP and 0.46 pg mL^-1 for hs-cTnI; corresponding limits of quantification were 18.7 and 1.35 pg mL^-1. Across matrix lots and concentration levels, recoveries were 93.1-107.8% and total coefficients of variation were 4.8-9.4%. Thirty-six independently prepared, blinded artificial-serum specimens representing four dual-biomarker phenotypes were compared with electrochemiluminescence and chemiluminescent microparticle immunoassays. Under an equal-error-variance assumption, Deming slopes were 0.963 and 1.012, concordance correlation coefficients were 0.9951 and 0.9930, and concentration-quadrant agreement was 35/36. Grouped validation and specimen-level comparison assessed the dual readout without treating spatial spectra as independent replicates. This architecture provides a controlled route to simultaneous cardiac-biomarker measurement in artificial serum.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149356958","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}

{"title":"Uncovering variability in 2,4,6-trinitrotoluene (TNT) odor signatures through thermal desorption-GC/MS.","authors":"Dawn M Mills, Janet Crespo-Cajigas","doi":"10.1039/d6ay02007k","DOIUrl":"https://doi.org/10.1039/d6ay02007k","url":null,"abstract":"<p><p>The odor signature of 2,4,6-trinitrotoluene (TNT) has remained incompletely characterized because of its low vapor pressure and methodological challenges associated with vapor analysis. Previous studies have detected TNT in headspace samples but have often emphasized volatile compounds, particularly 2,4-dinitrotoluene (2,4-DNT), rather than comprehensively characterizing TNT volatiles. An in-depth understanding in variability of TNT volatiles may inform the development and evaluation of representative canine training aids. This study applied a non-targeted thermal desorption gas chromatography-mass spectrometry (TD-GC/MS) approach to characterize TNT odor signatures across powder, flake, and cast morphologies. TNT sample headspace was collected using a microchamber thermal extractor. TD conditions were optimized through univariate experiments. The limit of detection for TNT was 40 ng µL^-1. Twelve volatile compounds were detected across samples, including TNT, related nitroaromatics, dinitrotoluene isomers, TNT positional isomers, and industrial volatile compounds. Statistical filtering using analysis of variance (<i>p</i> < 0.05), combined with a fold change criterion (≥3) identified five volatile compounds contributing to differences among samples. Principal component analysis showed substantial similarity among TNT odor signatures, alongside variation associated with sample morphology and composition. Two principal components explained 77.29% of the variance. Notably, 2,4-DNT, despite being the most abundant peak, was not retained as a discriminatory feature. These findings demonstrate that TNT samples share common chemical features with subtle differences in compound occurrence and relative abundance. This characterization provides an analytical foundation for investigating the representativeness of canine training aids and for future studies examining whether chemical variation among authentic TNT materials influences canine detection and generalization.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149356960","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}

{"title":"g-C₃N₄@Co-BTC nanohybrid-modified electrode for sensitive electrochemical determination of resorcinol in environmental samples.","authors":"Abdirashid Adam Isak, Ali Hyder, Mustafa Soylak","doi":"10.1039/d6ay01966h","DOIUrl":"https://doi.org/10.1039/d6ay01966h","url":null,"abstract":"<p><p>Resorcinol is a toxic dihydroxybenzene compound widely released from industrial activities, and its persistence in water can cause serious environmental and health concerns. Hence, developing a simple, sensitive, and reliable method for its trace-level determination is highly important. In this work, a g-C₃N₄@Co-BTC nanohybrid-modified screen-printed carbon electrode (g-C₃N₄@Co-BTC/SPCE) was developed for the electrochemical detection of resorcinol. The prepared nanocomposite was investigated using FTIR, XRD, SEM, and EDX to confirm its structural, morphological, and elemental properties. The electrochemical performance of the modified electrode was screened by CV, EIS, and DPV. The g-C₃N₄@Co-BTC/SPCE exhibited enhanced electrocatalytic activity toward resorcinol oxidation due to the synergistic effect of g-C₃N₄ and Co-BTC, thereby improving active surface area, electron transfer, and sensing response. Under optimized conditions, the sensor showed a wide linear range from 0.04 to 105 µM with a low limit of detection of 1.2 nM. The practical performance of the sensor was further tested in industrial wastewater and tap water, giving satisfactory recoveries of 96.3-102.3% with RSD values of 2-5%. These results confirm that the g-C₃N₄@Co-BTC/SPCE sensor is a promising platform for fast, sensitive, and practical monitoring of resorcinol in environmental water samples.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149356959","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}

{"title":"Evaluation of a simple visual acetylcholinesterase inhibition-based paper strip assay for detection of carbamate pesticides.","authors":"Acharya Balkrishna, Sejal Mishra, Nandini Sharma, Vedpriya Arya, Rohini Bhat","doi":"10.1039/d6ay01534d","DOIUrl":"https://doi.org/10.1039/d6ay01534d","url":null,"abstract":"<p><p>Carbamate pesticides, which are widely used in agriculture, pose serious food safety concerns, necessitating rapid and accessible detection methods. In this study, we report a simple, low-cost, and instrument-free paper strip assay for visual screening of carbamate residues based on acetylcholinesterase (AChE) inhibition. Unlike conventional biosensors that rely on surface-immobilized enzymes, which often suffer from activity loss, diffusional constraints, and short shelf-life, the present assay decouples the biocatalytic process into a simple homogeneous liquid-phase inhibition step (using BSA-stabilized lyophilized AChE) and a solid-phase chromogenic readout (substrate-loaded strip). The assay produces a distinct blue-to-pink color change using indoxyl acetate as a chromogenic substrate. The developed assay demonstrated high detection sensitivity for six carbamate pesticides (carbofuran, bendiocarb, carbosulfan, aminocarb, fenobucarb, and propoxur) with visual limits of detection ranging from 0.01 to 0.5 ppm. The developed assay showed high reproducibility and sensitivity when tested with real food samples following QuEChERS extraction. The substrate-loaded strips remained stable for two months at 4 °C, while the lyophilized enzyme retained activity for more than one year. Owing to its low cost (no complex synthesis required), ease of use, long shelf life and instrument-free visual readout, the assay holds potential as a practical preliminary screening tool for routinely monitoring of cholinesterase-inhibiting pesticide residues in agricultural products, with particular applicability to carbamates.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149331715","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}

{"title":"Dual-functional <i>Ficus religiosa</i> leaf vein-network scaffolds modified with a bio-derived chitosan/Ag@MgO nanocomposite interface for the efficient electrochemical detection of vitamins B₂ and B₁₂.","authors":"Sarita Shaktawat, Pooja Singh, Jay Singh","doi":"10.1039/d6ay02039a","DOIUrl":"https://doi.org/10.1039/d6ay02039a","url":null,"abstract":"<p><p>This work presents a cutting-edge, bio-derived flexible scaffold-integrated electrochemical biosensor designed to advance sustainable and low-cost sensing technologies, in alignment with the Sustainable Development Goals (SDGs). A naturally derived flexible scaffold was fabricated from the leaf lamina and venation network of <i>Ficus religiosa</i> (<i>F. religiosa</i>, peepal tree), which was interfacially engineered with a conductive and adhesive chitosan (CHNs) polymer. The CHNs coating facilitated strong interaction with the leaf-scaffold matrix while providing an effective platform for subsequent nanomaterial integration. Hydrothermally synthesized silver-decorated magnesium oxide nanocomposites (Ag@MgO NCs) were validated by characterisation methods such as XRD, UV-vis, FTIR, and PL spectroscopies, XPS, TEM, HR-TEM, FE-SEM and EDX. They were subsequently incorporated into the L-CHNs scaffold, substantially improving the electrochemical conductivity and active surface area (0.2082 cm²) of the resulting L-CHNs/Ag@MgO NC bioelectrode. The fabricated bioelectrode was validated by confocal microscopy and FE-SEM images and employed for the nonenzymatic electrochemical detection of vitamins B₂ and B₁₂, two essential micronutrients whose abnormal concentrations are associated with adverse health effects. Differential pulse voltammetry (DPV) demonstrated distinct and concentration-dependent electrochemical responses for both analytes. For vitamin B₂, the sensor exhibited a linear concentration range of 1-100 µM, a sensitivity of 21.3256 × 10^-5 mA µM^-1 cm^-2, a limit of detection (LoD) of 0.049 µM and a limit of quantification (LoQ) of 0.151 µM. In contrast, vitamin B₁₂ was detected over concentration ranges of 1-100 pM with a sensitivity of 11.76972 × 10^-6 mA pM^-1 cm^-2 and 100-1500 pM with a sensitivity of 7.40412 × 10^-7 mA pM^-1 cm^-2, along with an exceptionally low LoD of 0.088 pM and an LoQ of 0.157 pM. The analytical selectivity and practical applicability of the L-CHNs/Ag@MgO NC biosensor were further validated through interference studies and spiked serum-sample analysis. Moreover, the bio-derived electrode demonstrated satisfactory stability, rapid response, and reusability, highlighting the multifunctional potential of the <i>F. religiosa</i>-derived scaffold as a sustainable electrode architecture. Overall, this study reports the novel integration of a renewable biological scaffold, chitosan, and Ag@MgO nanocomposites for sensitive nonenzymatic electrochemical vitamin sensing and provides a promising platform for the development of sustainable, flexible, and resource-efficient biosensors for future point-of-care applications.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149331714","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}

{"title":"Sorbent-based active sampling method for the simultaneous analysis of very volatile, volatile, and semi-volatile organic compounds.","authors":"Matthias Richter, Elevtheria Juritsch","doi":"10.1039/d6ay02077a","DOIUrl":"https://doi.org/10.1039/d6ay02077a","url":null,"abstract":"<p><p>A thermal desorption gas chromatography-mass spectrometry (TD-GC/MS) method is presented that combines a novel sorbent configuration (Carbograph 5TD and Carbosieve™ SII) with two capillary columns connected in series: a porous layer open tubular (PLOT) column for very volatile organic compounds (VVOCs) and a conventional column for volatile and semi-volatile organic compounds (VOCs and SVOCs). The method addresses the lack of a standardised approach for the simultaneous determination of VVOCs, VOCs, and SVOCs in indoor air within a single analytical run. Validation using a mixture of 69 compounds demonstrated high precision, excellent linearity, and low limits of quantification (LoQs). Repeated measurements yielded coefficients of variation below 10% for most analytes. Across calibration ranges from below 1 ng to above 200 ng, coefficients of determination (<i>R</i>²) exceeded 0.99 for almost all compounds. Based on a sampling volume of 1 L, LoQs were below 10 µg m^-3 for 76% of analytes and were comparable to or lower than literature values. Humidity effects were most pronounced for highly polar compounds but were less influential than PLOT column length. A 3 m PLOT column enabled analysis of the entire analyte range in a single run, albeit with reduced chromatographic resolution. This limitation was largely mitigated by evaluating characteristic target ions. Extending the PLOT column to 6 m substantially improved resolution but decreased sensitivity for SVOCs. The optimum column configuration therefore depends on the analytical objective. The proposed method enables simultaneous characterisation of indoor air contaminants across a broad volatility range and may improve the efficiency and cost-effectiveness of emission testing and indoor air investigations.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149331717","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}

{"title":"PCR-amplified blaKPC-2-triggered Cas12a activation coupled with DNA cube-confined Fc reporter cleavage on a Ti₃C₂/CsPbBr₃@PDA@Au/GCE dual-mode ECL/SERS interface.","authors":"Yijin Chen, Jiangbin Huang, Lusheng Wen, Qigan Zhu, Jinfa Liu, Jiarong Meng, Le Yu","doi":"10.1039/d6ay01274d","DOIUrl":"https://doi.org/10.1039/d6ay01274d","url":null,"abstract":"<p><p>Rapid and reliable detection of antibiotic resistance genes is essential for guiding antimicrobial therapy and controlling the spread of carbapenem-resistant pathogens. Herein, we developed a PCR amplicon-activated CRISPR/Cas12a-regulated dual-mode electrochemiluminescence/surface-enhanced Raman scattering biosensor for sensitive detection of the blaKPC-2 resistance gene. A specific blaKPC-2 fragment containing the selected TTTG PAM region was amplified by PCR and used as a double-stranded DNA activator for the crRNA/Cas12a complex. After target recognition, activated Cas12a cleaved the Fc-labeled reporter segments integrated into a DNA cube scaffold assembled on the Ti₃C₂/CsPbBr₃@PDA@Au nanocomposite interface. In the initial state, Fc was positioned close to the Ti₃C₂/CsPbBr₃@PDA@Au-modified GCE surface, resulting in ECL quenching and strong SERS emission. Upon Cas12a-mediated cleavage of the exposed ssDNA reporter segments, Fc-containing fragments were released from the interface, leading to ECL recovery and SERS attenuation. Therefore, the target-induced process enabled an anti-correlated ECL-on/SERS-off signal conversion, and the ratiometric value <i>R</i> = <i>I</i>_ECL/<i>I</i>_SERS was used for quantitative analysis. The concentration-dependent response was empirically fitted over 10-10⁷ copies per µL, whereas the 10⁸ copies per µL group exhibited upper-range response compression. Boundary back-calculation indicated that further quantitative validation is required. Blank-response inverse prediction gave a model-dependent response-equivalent concentration of approximately 1.06 copies per µL; Poisson sampling gave a 95% molecular-sampling threshold of approximately 3.0 copies per µL for a 1.0 µL input. Neither descriptor is an experimentally determined detection or quantification limit. The platform also exhibited good selectivity against other resistance genes and non-target bacterial genomic DNA, together with satisfactory repeatability, reproducibility, stability, and acceptable spike-recovery performance in 10% diluted serum as a model biological matrix, providing preliminary evidence of matrix tolerance rather than clinical validation. This work provides a self-calibrated dual-mode strategy for antibiotic resistance gene detection, while further validation using bacterial lysates, extracted bacterial genomic DNA, and clinical bacterial isolates is required before diagnostic application. qPCR supported linear amplification over 10-10⁷ copies per µL; endpoint responses remained observable through 10⁸ copies per µL, where quantitative resolution was reduced.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149331716","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}