Analytica Chimica Acta最新文献

{"title":"Electrochemistry Sensing of Ascorbic Acid based on Conductive Metal-organic Framework (Cu3(benzenehexathiol)) Nanosheets Modified Electrode","authors":"Runhao Yuan, Xiaolong Zhong, Weiming Sun, Jian Wang, Chuanhui Huang, Zhenyu Lin, Jianping Zheng","doi":"10.1016/j.aca.2025.343980","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343980","url":null,"abstract":"<h3>Background</h3>Bulk-type conductive metal-organic frameworks (c-MOFs) had been applied to modify the electrode and used in electrochemical sensing because of the high conductive properties. But which still suffer from low mass permeability, restricted active site exposure, and poor accessibility due to the coordination saturation at metal sites in the bulk-type c-MOF. Recent studies have demonstrated that transforming bulk-type MOFs into MOFs nanosheets (NSs) can maximize the exposure of active sites and mass transfer. However, c-MOF NSs have rarely been applied in electrochemical sensing.<h3>Results</h3>This study presents NSs type c-MOF Cu₃(benzenehexathiol) (CuBHT), synthesized using a simple sacrificial template method. CuBHT NSs were modified onto a glassy carbon electrode (GCE) to prepare CuBHT NSs/GCE, which was then applied to sense the model target ascorbic acid (AA), the system exhibits high sensitivity of 1.521 mA mM^-1 cm^-2 and a wide linear range of 1-789 μM, low detection limit of 0.46 μM. The sensitivity is 1.90 times higher than that of bulk-type CuBHT nanoparticles (NPs) modified GCE, which can be attributed to the CuBHT NSs having more exposed Cu sites on their surfaces. CuBHT NSs/GCE was then used to monitor AA levels in human sweat during daily activities or exercise, and the results indicated high reliability compared to the vitamin C ASA kit method.<h3>Significance</h3>The design of c-MOF CuBHT NSs/GCE lead to better performance in terms of sensitivity and low detection limit in AA sensing compared to bulk-type nanoparticles. The AA sensing mechanism based on CuBHT was investigated, and the sensing system was demonstrated by detecting AA in sweat. This work advances both the fundamental understanding and practical applications of c-MOF NSs in AA sensing.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"72 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Instant Synthesis of Bimetallic CuCo PBA Nanozyme for Efficient Colorimetric Immunoassay of Carcinoembryonic Antigen","authors":"Xiaoqin Li, Huizi Lin, Xuwei Chen, Fenqiang Luo, Rong Zhang, Xiaoyan Deng, Youxiu Lin, Dianping Tang, Wenqiang Lai","doi":"10.1016/j.aca.2025.343981","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343981","url":null,"abstract":"Colorimetric immunoassays are widely used for biomarker detection, offering advantages of simplicity, sensitivity, and cost-effectiveness. Recent advancements focus on improving the catalytic activity of nanozymes for enhancing the sensitivity and accuracy of such assays. Bimetallic CuCo Prussian blue analog (CuCo PBA) has emerged as promising candidates due to their excellent peroxidase-like activity. However, their instant synthesis and integration into immunoassays for the rapid detection of biomarkers like carcinoembryonic antigen (CEA) remain underexplored. This study presents an innovative approach using CuCo PBA nanozymes for colorimetric immunoassays with immediate generation and application. In this study, CuCo PBA nanozymes were synthesized instantly by reacting Cu²⁺ with K₃[Co(CN)₆] (&lt;1 min), and their peroxidase-like activity was exploited for a colorimetric immunoassay system targeting CEA. The system demonstrated a clear blue color change upon the reaction of CuCo PBA with H₂O₂ and 3,3',5,5'-tetramethylbenzidine (TMB), enabling sensitive detection. The assay was optimized for various parameters, including pH, temperature, and material ratio. A linear response was obtained for CEA detection over a concentration range of 0.05–60 ng/mL with a limit of detection (LOD) of 22 pg/mL. The integration of glucose oxidase (GOx) mediated the generation of H₂O₂, triggering the colorimetric reaction. This instantaneous CuCo PBA-based system effectively detected CEA in human serum samples, highlighting its potential for rapid diagnostic applications. This work introduces a novel approach for rapid and sensitive colorimetric immunoassays using CuCo PBA nanozymes that are synthesized on-demand and immediately applied. The system allows for efficient CEA detection with an exceptionally low detection limit, offering great potential for clinical diagnostics. The instant generation and application of CuCo PBA nanozymes in immunoassays represent a significant advancement in point-of-care testing technologies.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"39 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical Detection of Creatinine at Picomolar Scale with an Extended Linear Dynamic Range in Human Body Fluids for Diagnosis of Kidney Dysfunction","authors":"Sanya Khursheed, Sumera Sarwar, Dilshad Hussain, Muhammad Raza Shah, Jiri Barek, Muhammad Imran Malik","doi":"10.1016/j.aca.2025.343978","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343978","url":null,"abstract":"<h3>Background</h3>Creatinine levels in different body fluids can serve as an important biomarker for kidney functioning relevant to prostate cancer and chronic kidney disease (CKD). Creatinine levels vary in concentration in different body fluids, such as blood, urine, and saliva. Unlike previously reported sensors, the developed creatinine sensor can be employed for all levels of creatinine in samples of real patients.<h3>Results</h3>In this study, an efficient voltammetric sensor for creatinine is developed by modifying a glassy carbon electrode (GCE) with poly(ethyleneimine) (PEI) capped silver nanoparticles at titanium dioxide (PEI-AgNPs)/TiO₂, i.e., titanium dioxide (TiO₂)/graphene oxide (GO) nanocomposites (Ag@GO/TiO₂-GCE). The Ag@GO/TiO₂ nanocomposite was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential,Fourier transform infrared (FT-IR) spectroscopy, and UV-Vis spectrophotometry. Various voltammetric techniques namely cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV) were employed. The Ag@GO/TiO₂-GCE demonstrated good selectivity, stability, and a quick response time of 1.0 second for creatinine. An extended linear dynamic range (LDR) of creatinine from 0.01 pM (DPV) to 1.0 M (CV) based on different voltammetric techniques is imperative for detecting diverse creatinine levels in various body fluids. The LOD and LOQ of the developed creatinine detection method were found to be 1.15 pM and 3.5 pM, respectively. The electrochemical sensor exhibited an exceptionally high sensitivity of 15.74 μApM^-1cm^-2.The body fluids from healthy volunteers were spiked with a known amount of creatinine to evaluate sensor efficiency in the context of recovery. Finally, blood serum, saliva, and urine samples of kidney patients were analyzed for creatinine levels.<h3>Significance</h3>An important merit of the developed creatinine sensor is its ability for non-invasive point-of-care diagnosis in saliva with more than 90% recovery. The comparison of the developed method with the standard Jaffes’ colorimetric method endorsed its reliability and extended ability for the samples where Jaffes’ method fails. The low LOD, high sensitivity, extended LDR, and low-cost render the possibility of adopting this method for point-of-care diagnosis.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"25 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rational Design and Pairing of Single-Domain Antibodies for Developing Rapid Detection Methods for Botulinum Neurotoxins A and B","authors":"Ruomei Lv, Jiaxin Li, Xinyu Fang, Li Tang, Rui Shi, Jin Wang, Wenjing Zhang, Jinglin Wang, Guangyu Zhao, Jing Wang, Shan Gao, Xuefang Xu, Lin Kang, Wenwen Xin","doi":"10.1016/j.aca.2025.343977","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343977","url":null,"abstract":"<h3>Background</h3>Botulinum neurotoxin (BoNT) is a toxin produced by <em>Clostridium botulinum</em> that can cause neurological dysfunction in humans and animals, with BoNT/A and BoNT/B being responsible for the majority of poisoning cases. Due to its extremely high toxicity, BoNT is considered a potential biological warfare and bioterrorism agent. Currently, there is a lack of rapid and highly sensitive detection methods for botulinum toxin, making the development of fast and effective detection methods for BoNT essential. Here, we developed rapid detection methods for BoNT/A and BoNT/B based on nanobodies, including two ELISA methods and Time-resolved fluorescence immunochromatography assay (TRFICA).<h3>Results</h3>By analyzing the binding epitopes of BoNT/A, BoNT/B, and nanobodies, we rationally designed and prepared six nanobodies, adding a Trx tag at the N-terminus, a 6×His tag at the C-terminus, and fusing them with HRP, for use in developing two ELISA methods for BoNT/A and BoNT/B detection. Additionally, Time-resolved fluorescence immunochromatography assay (TRFICA) was developed in combination with lanthanide microspheres. These three methods were validated using simulated samples containing BoNT in milk, sand, and human serum. The limits of detection for ELISA 1 and 2 were 0.17 and 4.5 ng/mL, respectively, while the TRFICA had a detection limit of 0.05 ng/mL and provided results in approximately 15 minutes. TRFICA also successfully detected clinical samples, with a sensitivity of 98% and a specificity of 96.7%.<h3>Significance</h3>Overall, the TRFICA method we established has a short detection time, is easy to operate, and effectively addresses the challenge of rapid BoNT detection in clinical diagnostics, with significant clinical application value. Furthermore, based on the sequences and binding epitopes of nanobodies, we rationally designed six nanobodies and successfully applied them in the development of various BoNT detection methods. This approach and pipeline provide valuable guidance for the future development of rapid, low-cost detection methods.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"21 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering Bio-Inspired Nanochannels with pH-Responsive Gates for Direct Detection of Glucose in Human Blood Serum","authors":"Yinde Wu, Jialun Li, Yunzhou Chen, Xuancheng Liu, Yueyang Zhang, Chongxuan Xiao, Zihao Li, Yan-Yan Song, Tian Shen, Xiaona Li","doi":"10.1016/j.aca.2025.343973","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343973","url":null,"abstract":"<h3>Background</h3>An abnormal blood glucose (Glu) level is a key signal of diabetes. The gluconic acid produced by Glu catalytic oxidation can cause changes in pH value.<h3>Results</h3>Inspired by nature, in which organisms use pH as a chemical gate to regulate ion transport through cell membranes, we report a pH-gated electrochemical luminescence (ECL) sensing system for Glu detection based on the relationship between Glu metabolism and pH. The pH gate was designed on a TiO₂ nanochannel membrane (NM) by modifying the channel entrance with polystyrene-b-poly(4-vinylpyridine) (P4VP) chains that convert from a hydrophobic into a hydrophilic state via a pH-responsive conformational switching at pKa 5.2. Due to the nanoconfinement effect of zeolite imidazolate (ZIF-8) frameworks and TiO₂ nanochannels, the glucose oxidase (GOD) embedded in ZIF-8 exhibits enhanced catalytic efficiency for Glu oxidation, enabling the acidic product to regulate the hydrophilicity of the P4VP-based pH-responsive gate. The ECL luminophore Ru(dcbpy)₃²⁺ subsequently passes through the hydrophilic gate to reach the detection cell. This pH-gated Glu-responsive NM can effectively separate biological matrices from the detection cell, allowing direct sensing of Glu in complex biomatrices.<h3>Significance</h3>The ECL technology, combined with the pH-triggered gate design enables straightforward Glu determination in undiluted serum, demonstrating an alternative ECL device for pretreatment-free clinical analysis.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"11 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Raman Spectroscopic Detection of Synthetic Cannabinoid-related 1H-indazole-3-carboxamide on Seized Paper Stamps: A Forensic Challenge in Providing Nondestructive Analyses and Feasible Counterevidence","authors":"Luciano S.F. Silva, Lucas S. Abreu, Eliani Spinelli, Glaucio B. Ferreira, Lucas M. Duarte","doi":"10.1016/j.aca.2025.343975","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343975","url":null,"abstract":"<h3>Background</h3>Synthetic cannabinoids challenge forensic laboratories, which typically rely on sample-consuming chromatography-mass spectrometry. Criminalistic regulations mandate preserving seized material for potential judicial counterevidence requests. Raman spectroscopy emerges as a promising detection method, maintaining the chemical integrity of evidence for future examinations.<h3>Results</h3>This study utilized two distinct Raman spectroscopy methodologies to detect 1H-indazole-3-carboxamide (core-linker) in synthetic cannabinoids found on seized paper stamps: 785 nm dispersive Raman microscope (direct analysis) and 1064 nm FT-Raman (with difference spectroscopy). Both methods confirmed seven core-linker bands, corroborated by Density Functional Theory calculations. Gas Chromatography-Mass Spectrometry, Electrospray Ionization Mass Spectrometry, and Proton Nuclear Magnetic Resonance analyses confirmed the presence of ADB-5'Br-butinaca, representing its first documented identification in Rio de Janeiro, Brazil.<h3>Significance</h3>The present investigation demonstrates Raman spectroscopy's efficacy for non-destructive detection of synthetic cannabinoids in seized materials. By identifying a core-linker and confirming ADB-5'Br-butinaca, it addresses the forensic challenge of preserving evidence while enabling rapid analysis. Both vibrational spectroscopy approaches offer highly effective tools for selective structural elucidation of this globally expanding class of psychoactive substances.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"22 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual LC column characterization for mass spectrometry-based small molecule profiling of human plasma and serum","authors":"Žiga Tkalec, Štěpán Koudelka, Jana Klánová, Elliott J. Price","doi":"10.1016/j.aca.2025.343942","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343942","url":null,"abstract":"<h3>Background</h3>Analyte annotation confidence in untargeted liquid chromatography mass-spectrometry (LC-MS) based chemical analysis can be enhanced by leveraging retention time information. For this, the chromatographic characteristics of the analytical system used should be well characterized. In this study, we measured 604 diverse chemical standards to characterize a dual LC setup consisting of pentabromobenzyl (PBr) and type-C silica hydride (SiH) columns operating in reversed-phase (RP) and aqueous normal-phase (ANP) mode, respectively.<h3>Results</h3>ANP and RP separations individually retained 40 % and 64 % of standards in cLogP range from −6.60 to 8.67 and -3.34 to 12.95, respectively. Using both columns, the coverage increased to 79 % of standards with cLogP range from -6.60 to 12.95 (median cLogP = 1.63). Retention selectivity follows the number of basic nitrogen atoms in the molecule on SiH column and polarity (cLogP) on PBr column. Column repeatability and reproducibility were tested in triplicate using a chemically diverse subset of 108 standards. Repeatability of retention times, peak widths and peak areas was 0.3 %,14 %, 4 % for SiH column and 0.2 %, 12 %, 4 % for PBr column. Similarly, reproducibility was 15 %, 34 %, 30 % for SiH column and 9 %, 18 % and 34 % for PBr column. Predictive RT models were developed based on experimental RT data, achieving R² values of 0.92 and 0.96, with mean absolute errors of 0.29 min and 0.27 min for SiH and PBr columns, respectively.<h3>Significance</h3>As proof of concept, 129 metabolites were annotated in pooled human serum and plasma by matching standard or predicted RT on one or both columns. The RT models and MS2 spectra of standards are openly available, facilitating uptake of this well-characterized chromatographic system to increase confidence in analyte annotation.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"8 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-nanozyme cascade system for boosting colorimetric sensing by selective etching bimetallic MOFs","authors":"Yuhang Lin ,&nbsp;Tianshuo Wang ,&nbsp;Yuanhao Liu ,&nbsp;Lianxi Pu ,&nbsp;Mingxuan Jia ,&nbsp;Xilong Zhou ,&nbsp;Lijun Ding ,&nbsp;Weiran Zhu ,&nbsp;Kun Wang","doi":"10.1016/j.aca.2025.343976","DOIUrl":"10.1016/j.aca.2025.343976","url":null,"abstract":"<div><h3>Background</h3><div>Rational engineering of multienzyme system architecture is essential for achieving high-performance multi-enzyme cascade catalysis in sensing applications. In this context, the initiation step of the cascade reaction pathway plays a pivotal role in enhancing catalytic efficiency. CoFe Prussian blue analogue (CoFePBA), a dual-metal organic framework, is an ideal template for multi-enzyme design, leveraging its diverse dual-metal ion functionalities and synergistic effects. Defect engineering approaches enable the fine-tuning of catalytic properties, optimizing electron transfer and promoting reaction intermediates. Therefore, the rational design of the multienzyme system structure is critical for efficient cascade catalysis.</div></div><div><h3>Results</h3><div>In this study, we utilized deep eutectic solvents (DES) to selectively induce Co defects in CoFePBA (CoFePBA-DES) under mild conditions, providing more active sites and enhancing the Co²⁺/Co³⁺ ratio, significantly boosting the initial step of the cascade reaction. This then triggers the three-enzyme cascade reaction system—oxidase (OXD), superoxide dismutase (SOD), and peroxidase (POD)—which facilitates the conversion of products from O₂ to O₂^•- to endogenous H₂O₂, achieving a two-fold increase in its yield and subsequently to OH^• in a sequential reaction, demonstrating excellent multi-enzyme cascade catalytic activity. Utilizing the inhibitory effect of glutathione (GSH) on multi-enzyme cascade catalytic activity, we designed a highly efficient and rapid colorimetric sensor for the sensitive detection of GSH, with a detection range of 0.5–160 μM and a detection limit of 0.15 μM.</div></div><div><h3>Significance</h3><div>Compared to traditional etching techniques, DES-based methods offer superior selectivity, lower toxicity, and better structural preservation of the MOF framework, making them a promising tool for controlled defect engineering. By selectively creating defects, the initial steps of the cascade reaction are activated, resulting in a significant enhancement of catalytic activity. This approach provides a viable pathway for the preparation of high-performance dual-metal catalysts for cascade reaction catalysts and sensing applications.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1353 ","pages":"Article 343976"},"PeriodicalIF":5.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Label-free Detection of E. Coli by Alternating Current Electrokinetic Capacitive Sensors","authors":"Xingchi Liu, Xinchen Qiu, Zhang Pan, Jing Chen, Shanshan Li, Jingmeng Cheng","doi":"10.1016/j.aca.2025.343972","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343972","url":null,"abstract":"<h3>Background</h3>Escherichia coli (<em>E. coli</em>) is one of the most common pathogens in water and foods, and it poses a significant threat to global public health, particularly in low- and middle-income countries. However, most of the state-of-art detection method for E. coli bacteria sensing needs fluorescence staining or pre-immobilizations or specific biomaker as labels before tests, making the detection process a time costing and labor intensitive work. Thus, it is desirable to develop a label-free and no-immobilization detection method for the sensitive detection of <em>E. coli</em> or other pathogens. <u>Results</u>: In this work, we developed a sensitive method for <em>E. coli</em> detection without any labels or pre-immobilizations. Here the source AC signal provides ACEK effects to trap bacteria onto the electrode surface. As the source AC signal is cut off, the enriched bacteria would release from sensor electrodes. Then, a significant interfacial capacitance change along with particle releasing is observed by applying a measurement AC signal. The DEP capture of <em>E. coli</em> bacteria at different AC frequencies and voltages are experimentally investigated to optimize the performance of capacitive sensors. To note, the total area of our sensitive unit can be as large as 2 mm×2 mm with the geometry design of isomotive DEP. Capacitive sensing tests of river water collected from local river and tap water with several control groups are performed to show its reliability as a biosensing approach for the sensitive detection of <em>E. coli</em>. <u>Significance:</u> The most significant advantage of this method is that we do not need to pre-immobilize any probes (antigens, or antibodies, etc.) or take incubation onto the sensor electrode before taking capacitance measurement. Moreover, the straight forward operation is pre-immobilization free, and therefore it meets the requirements of on-site bacteria detection for pathogen detection in water quality monitoring or food safety.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"217 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143695751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser-Induced Graphene Electrode Modified by Platinum nanoparticle/Zein/Gelatin/Glucose Oxidase for Non-Invasive Glucose Sensor in Multiple Biofluids","authors":"Kittiya Sakdaphetsiri, Thana Thaweeskulchai, Wiwittawin Sukmas, Joseph Wang, Albert Schulte, Nadnudda Rodthongkum","doi":"10.1016/j.aca.2025.343974","DOIUrl":"https://doi.org/10.1016/j.aca.2025.343974","url":null,"abstract":"<h3>Background</h3>A non-invasive glucose biosensor for multiple biofluids based on platinum nanoparticle (Pt-NP)-modified laser-induced graphene (LIG) electrodes coated with a zein/gelatin/glucose oxidase (GOx) for amperometric detection of glucose is created. The biosensor fabrication is cost-effective and scalable, as it combines simple LIG electrode fabrication with direct Pt-NP electrodeposition and a sequence of drop-and-dry steps for zein and gelatin layer then GOx enzyme. The Pt-NP modification on the LIG electrode functions as an electrocatalyst to enhance the anodic H₂O₂ signal, which is directly proportional to glucose concentration. The zein layer acts as a diffusion barrier to mitigate potential interferences, while the gelatin film provides amine groups for the glutaraldehyde-mediated immobilization of the GOx enzyme.<h3>Results</h3>The key parameters of LIG were optimized, such as power laser, number of Pt-NP cycles, and zein concentration. In addition, LIG was characterized by Raman spectroscopy, SEM, and cyclic voltammetry (CV) to ensure graphitization and electron transfer performance. The as prepared LIG/Pt-NP/Zein/Gel-GOx glucose biosensor was in anodic H₂O₂ detection mode and tested for glucose measurements in multiple biofluids including sweat, saliva, and urine. At H₂O₂ detection potential of +0.4 V, a linear detection range from 0 up to 2 mM glucose was obtained with a limit of detection (LOD) of 0.01 mM, making it feasible for glucose determination in various clinically relevant biofluids. By comparing with the commercial SPE, this LIG-based sensor offered much higher detection sensitivity towards both H₂O₂ and glucose, making it a superior choice for electrochemical analysis.<h3>Significance</h3>This LIG/Pt-NPs/Zein/Gel-GOx offers a practical and high sensitivity approach to glucose measurement with a wide linearity for multiple biofluids. Given the straightforward and easily scalable process, this high-performance, LIG-based glucose biosensor presents a compelling alternative over commercial screen-printed electrode. Highlighted the novelty using zein as a protective layer to reduce interferences. Owing to the simplicity of fabrication with high potential for up-scaling, this high analytical performance biosensor might be an alternative tool for multiplex glucose biosensors in point-of-care applications.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"14 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}