Analytica Chimica Acta最新文献

{"title":"A novel photonic crystals electrochemical synchronous dual-mode sensor for perfluorooctanoic acid detection in textiles","authors":"Yameng Li,&nbsp;Ning Liu,&nbsp;Xiaoyi Yan,&nbsp;Zhenrun Li,&nbsp;Zhiquan Zhang,&nbsp;Qiang Ma","doi":"10.1016/j.aca.2025.344352","DOIUrl":"10.1016/j.aca.2025.344352","url":null,"abstract":"<div><h3>Background</h3><div>Perfluorooctanoic acid (PFOA) was a kind of persistent organic pollutant, which was the main active ingredient in antifouling treatments for textiles and leather products. However, PFOA was still produced and used on a large scale in many countries and regions with rapid industrialization. Therefore, it was significant to establish a detection method for PFOA in textiles. In this paper, we constructed a novel photonic crystals electrochemical synchronous dual-mode sensor based on differential pulse voltammetry (DPV) and electrochemiluminescence (ECL) for perfluorooctanoic acid detection in textiles.</div></div><div><h3>Results</h3><div>AgBiS₂ QDs with high ECL activity and good biocompatibility were prepared as nano-emitters. Meanwhile, silica (SiO₂) optical microspheres were used to form photonic crystals through interfacial self-assembly. Then, molecularly imprinted polymers (MIPs) were prepared on the voids of SiO₂ photonic crystals with dopamine (DA) as the functional monomer and PFOA as the template molecule. The photonic crystals significantly enhanced the ECL signal and increased the density of specific recognition sites in MIPs, which greatly improved the sensitivity of detection. In addition, liquid-liquid extraction of textiles using deep eutectic solvent (menthol: octanol 1:1) was used to pre-enrich PFOA. Finally, both DPV and ECL signals were generated in the synchronous dual-mode sensing system to detect PFOA successfully.</div></div><div><h3>Significance</h3><div>The ECL and DPV response showed good linear relationships with the concentration of PFOA with the ranges of 0.005 μM–50 μM and 0.2 μM–5.0 μM and the detection limits of 0.00168 μM and 0.067 μM, respectively. This sensor with the synchronized DPV-ECL dual-mode analysis introduced an innovative and sensitive method for PFOA detection.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344352"},"PeriodicalIF":5.7,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334996","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":"Derivatization for success: a tutorial review of liquid chromatography mass spectrometry method optimization for determining amino compounds","authors":"Riin Rebane, Ivo Leito","doi":"10.1016/j.aca.2025.344354","DOIUrl":"https://doi.org/10.1016/j.aca.2025.344354","url":null,"abstract":"The accurate determination of amino compounds in complex matrices is essential for a wide range of applications, from bioanalysis to industry. Liquid chromatography coupled with mass spectrometry (LC-MS) is a powerful analytical technique for their identification and quantification. However, the low ionization efficiency and poor retention of some amino compounds present a challenge in mass spectrometric detection, making derivatization a crucial step. This tutorial review provides a comprehensive guide to improving LC-MS methods through derivatization, enhancing detection and quantification. Key aspects of the optimization method are covered, including selection of suitable derivatization reagents, optimization of reaction and chromatographic conditions, and other practical aspects. Drawing on an extensive literature review and experience, this tutorial offers researchers valuable insights into refining LC-MS workflows for methods using derivatization, mainly to determine amino acids and biogenic amines. Serving as both an instructional guide and a practical reference, this study aims to advance the effectiveness of LC-MS-based methods for amino compound determination.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"15 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334993","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":"Facile fabrication of tailored Pepsin@COF nanobiohybrid platform for high-performance chiral separation","authors":"Jiale Zhang ,&nbsp;Qixuan Mu ,&nbsp;Xinyue Li ,&nbsp;Yifang Liao ,&nbsp;Ruijun Li ,&nbsp;Yibing Ji","doi":"10.1016/j.aca.2025.344351","DOIUrl":"10.1016/j.aca.2025.344351","url":null,"abstract":"<div><h3>Background</h3><div>Enzymes, with their broad chiral recognition capabilities, are promising but limited by stability issues. Covalent organic frameworks (COFs), with high surface area, porous structure, and biocompatibility, offer an ideal platform for enzyme immobilization. However, the non-matching between the large size of enzyme molecules and the pore size of COFs, along with conformational disturbances during the immobilization process, as well as the complex preparation, low efficiency, and poor stability of traditional enzyme-based chiral stationary phases (CSPs), hinders the application of highly chiral selectivity of enzyme in enatioseparation.</div></div><div><h3>Results</h3><div>A green synthesis strategy is introduced to overcome the limitations of conventional enzyme@COF synthesis, enabling the facile anchoring of pepsin onto TpPa-1 with small pores. The in-situ encapsulation approach facilitates high enzyme loading and excellent stability, which lead to the remarkable potential of Pepsin@TpPa-1 for enhanced chiral selectivity. Inspired by the in-situ concept, an innovative chromatographic column preparation technique is developed by growing Pepsin@TpPa-1 directly within capillaries, creating an capillary electrochromatography open-tube column (OT-CEC) with high-density chiral recognition sites, achieving efficient separation of diverse chiral drugs, including β-blockers, esterase inhibitors, and other types. The complex chiral recognition mechanism of pepsin is revealed at the molecular level, and the positive correlation between Pepsin@TpPa-1 activity and chiral selectivity is explored for offering theoretical support for designing high-performance chiral recognition platforms.</div></div><div><h3>Significance</h3><div>This study represents the first application of enzyme-COF composites in CEC CSPs, overcoming challenges like low enzyme loading and instability. This enzyme-based CSP facilitated the extensive separation of chiral drugs. A novel insight is provided into the recognition mechanism, as well as the relationship between pepsin's activity and its chiral selectivity. Furthermore, the highly stable chiral nanobiohybrid separation platform introduces a pioneering research paradigm for CSP development in OT-CEC.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344351"},"PeriodicalIF":5.7,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334992","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":"Ultrasensitive SERS detection of cytokines through specific binding and multiple reporter molecules","authors":"Hairong Chen ,&nbsp;Hengchang Zhang ,&nbsp;Lingfeng Duan ,&nbsp;Kaidi Sun ,&nbsp;Rui Li ,&nbsp;Yunxia Wang ,&nbsp;Jiacheng Yao ,&nbsp;Changchun Yan ,&nbsp;Ying Liu ,&nbsp;Ying Wu ,&nbsp;Guohai Yang ,&nbsp;Caiqin Han","doi":"10.1016/j.aca.2025.344355","DOIUrl":"10.1016/j.aca.2025.344355","url":null,"abstract":"<div><div>Interleukins (IL) play a vital part in molecular recognition as well as immune response, and their excessive or inappropriate production can lead to inflammatory and cardiovascular diseases, etc., which are harmful to human physical and mental health. Thus, there is a pressing need to develop a strategy for the rapid and highly sensitive detection of such low concentration substances. In this study, we developed a Surface enhanced Raman spectroscopy (SERS) immunosensor for qualitative and quantitative analysis of multiple cytokines (IL-1, IL-4 and IL-6). Three Raman reporters were modified on gold nanoparticles and coupled with corresponding antibodies to form immunoprobes. The silver nanospace folded rods were prepared by tilted angle deposition technique, connected with antibodies to form an immunosensor. When the target antigen appeared on the immunosensor, it would specifically bind with the antibody to form a “sandwich” structure. Respectively, the detection limits of IL-6, IL-1 and IL-4 were 1.00 pg/mL, 0.93 pg/mL and 1.00 pg/mL. The three inflammatory factors were successfully distinguished and predicted by machine learning. In addition, we detected and calculated the recovery of IL-6 cytokines in saliva samples. The method can achieve quantitative detection and qualitative differentiation of target detectors in a wide concentration range. Meanwhile, it has the advantages of rapidity, simplicity and high specificity, which has a broad application prospect in biomedical field.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344355"},"PeriodicalIF":5.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334997","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":"Sensitive enzymatic cycling assay for glutathione and glutathione disulfide content","authors":"Xinyue Lin ,&nbsp;Yajun Chu ,&nbsp;Qianhe Xu ,&nbsp;Qiuying Nie ,&nbsp;Cui Xu ,&nbsp;Jianguo Fang ,&nbsp;Junmin Zhang","doi":"10.1016/j.aca.2025.344348","DOIUrl":"10.1016/j.aca.2025.344348","url":null,"abstract":"<div><h3>Background</h3><div>It is crucial to develop reliable techniques for accurately detecting and measuring glutathione (GSH) and glutathione disulfide (GSSG) content in biological samples. However, there is currently not yet a full consensus on the best approach for preparing and analyzing samples to obtain accurate quantitative results.</div></div><div><h3>Results</h3><div>This study screened N-ethylmaleimide (NEM) as a masking agent and 5-sulfosalicylic acid (SSA) as a protein removal agent to establish a standard and stable method for GSH and GSSG determination. Subsequently, the method was validated in cells, mouse blood and tissues. Standard concentration curves were used to determine the levels of GSH and GSSG in HeLa and LO2 cells before and after treatment with the GSH inhibitor, buthionine sulfoximine (BSO). The results showed that after incubation with BSO, the total GSH and GSH/GSSG ratios were significantly lower than those in the control group. Likewise, BSO verification has also been successfully applied to the quantification of mouse tissue and blood. After incubation with BSO for 3 h, the GSH content in the liver and kidneys significantly decreased, and the GSH concentration in mouse plasma was about 50 μM.</div></div><div><h3>Significance</h3><div>This work demonstrates a sensitive and accurate enzymatic cycling method for the detection of GSH and GSSG content in cells, tissues and blood, helping to build consensus on GSH to GSSG ratios in different sample types.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344348"},"PeriodicalIF":5.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329465","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":"Sugaring-out assisted extraction (SoAE): A novel approach for the determination of Cd and Pb in milk by graphite furnace atomic absorption Spectrometry","authors":"Eduardoda Silva G. de Castro ,&nbsp;Ricardo J. Cassella","doi":"10.1016/j.aca.2025.344347","DOIUrl":"10.1016/j.aca.2025.344347","url":null,"abstract":"<div><h3>Background</h3><div>Milk and dairy products are significant from both nutritional and economic perspectives. As a result, they are subject to strict health surveillance and quality control protocols, making the development of reliable analytical methods a critical concern in the food industry. Due to the complex and variable chemical composition of milk matrix, sample preparation steps are often essential prior to the determination of metals using spectroanalytical techniques.</div></div><div><h3>Results</h3><div>This study introduces a novel sample preparation method for the determination of Cd(II) and Pb(II) in milk, based on extraction assisted by the sugaring-out effect (SoAE), using acetonitrile as the extraction solvent. Quantification of the analytes in the extracts was carried out using Graphite Furnace Atomic Absorption Spectrometry (GF AAS). The optimized method achieved limits of quantification (LoQs) of 0.24 μg kg⁻¹ for Cd(II) and 1.3 μg kg⁻¹ for Pb(II), with enhancement factors of 7.5 and 9, respectively. These LoQs are well below the maximum allowable limits for these contaminants in milk (50 μg kg⁻¹ for Cd(II) and 10 μg kg⁻¹ for Pb(II)), confirming the suitability of the method for routine quality control. The method was rigorously validated in accordance with requirements set by international regulatory bodies. Its accuracy, evaluated using a certified reference material (CRM), was 106 % for Cd(II) and 91.8 % for Pb(II).</div></div><div><h3>Significance</h3><div>The proposed method is novel, using the sugaring-out effect (SoAE) for the first time in metal determination of complex aqueous samples. It offers simplicity, speed, and accurate Cd(II) and Pb(II) determination without interferences. The SoAE approach shows promise for broader applications, including the separation and determination of other metals or organics in combination with various spectroscopic, chromatographic, and electroanalytical techniques.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344347"},"PeriodicalIF":5.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329126","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":"Double special bodyguard: Selenium-enhanced loop-mediated isothermal amplification combined with CRISPR/Cas12a biosensing strategy","authors":"Keyi Long ,&nbsp;Tiao Han ,&nbsp;Wenxi Hu ,&nbsp;Mei Yang ,&nbsp;Danqun Huo ,&nbsp;Zhen Huang ,&nbsp;Changjun Hou","doi":"10.1016/j.aca.2025.344353","DOIUrl":"10.1016/j.aca.2025.344353","url":null,"abstract":"<div><div>Cervical cancer is closely associated with human papillomavirus (HPV) infection, underscoring the necessity for effective HPV detection. Various biosensors utilizing isothermal amplification techniques have been developed for HPV DNA detection. These methods offer high sensitivity and specificity, making them suitable for point-of-care testing. However, the in vitro DNA polymerases used in these isothermal amplification methods lack a repair system, may leading to polymerization errors. This limitation highlights the need for improved detection methods that can enhance accuracy and reliability in HPV testing. Here, a sensing strategy called selenium nucleic acid-enhanced loop-mediated isothermal amplification (Se-LAMP) combined with CRISPR/Cas12a (SLC) was developed. The SLC has two specific bodyguards, which ensure the accuracy and specificity of biosensors through two aspects. One bodyguard is dNTPαSe, a supplement added to the initial Se-LAMP step, which guarantees the accuracy of DNA polymerase and reduces background signals. The other bodyguard is CRISPR system, integrating three functions of specific verification, signal amplification and signal output. CRISPR activation can only rely on Se-LAMP products successfully rechecked by crRNA. As a readable signal of SLC, the detection limit was as low as 0.38 copies/μL (0.64 fM) within 65 min, which was one order of magnitude lower than that of non-selenium-modified methods and two orders of magnitude lower than that of qPCR. The SLC is the first to use CRISPR system as the output mode of Se-LAMP, proving the CRISPR/Cas12a system has good recognition ability for selenium-modified nucleic acid. The ultrasensitive dual-specificity guard enables SLC, ensuring accuracy in biodetection. This innovation offers novel clinical testing approaches and holds significance for diagnosing and monitoring disease progression.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344353"},"PeriodicalIF":5.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329127","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":"Qualitative and quantitative analysis of highly-polar contaminants in Atlanta urban water","authors":"Francesc Labad,&nbsp;Sandra Pérez","doi":"10.1016/j.aca.2025.344349","DOIUrl":"10.1016/j.aca.2025.344349","url":null,"abstract":"<div><h3>Background</h3><div>Highly polar substances have fallen from the scope of investigations due to this lack of accumulation into organic materials and the analytical difficulty they present using “traditional” techniques. This study presents an integrated analytical approach combining liquid chromatography (LC) and travelling-wave ion mobility spectrometry (TWIMS) coupled with high-resolution mass spectrometry (HRMS) for the separation, detection, and quantification of 45 challenging contaminants in urban water matrices. The targeted analytes, including 41 very mobile compounds and 37 highly polar substances (log D_ow &lt; 0), represent compounds that are often poorly retained under conventional reversed-phase and HILIC LC conditions.</div></div><div><h3>Results</h3><div>TWIMS was used to determine the CCS of 33 small organic molecules (120–500 Da). A ΔCCS threshold of ≥0.5 % was identified as sufficient for proper separation on second-generation IMS instruments (resolving power &gt;300 Rp). In cases where LC provided inadequate retention, TWIMS proved to be an effective complementary technique by exploiting differences in molecular size, shape, and charge to resolve compounds based on their collision cross-section (CCS) values.</div><div>Surface water samples from the Chattahoochee River and tap water from Midtown Atlanta (USA) were analyzed, revealing that over 50 % of the targeted contaminants were detected in at least one matrix. Notably, compounds such as naphthalene-1-sulfonic acid, nicotine, and several per- and poly-fluoroalkyl substances (PFAS) were consistently observed, highlighting their ubiquitous occurrence in urban water impacted by industrial activities and heavy traffic.</div></div><div><h3>Significance</h3><div>The methodology employed not only improved the resolution and identification of small, highly polar molecules but also provided robust quantitative data essential for environmental monitoring and risk assessment. This approach underscores the potential of IMS as a valuable complementary tool to traditional LC-MS workflows in complex environmental analyses. Additionally, the data presented regarding the presence of highly polar substances in urban water matrices should inform stakeholders and implement preventive strategies.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344349"},"PeriodicalIF":5.7,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329128","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":"Innovative Microseparator Design for Enhanced Aerosol Separation","authors":"Pan Wang, Zhuo Gao, Changxing Li, Xiuli Gao, Jianlong Zhao, Shouqi Yuan, Shilun Feng","doi":"10.1016/j.aca.2025.344336","DOIUrl":"https://doi.org/10.1016/j.aca.2025.344336","url":null,"abstract":"<h3>Background</h3>The virtual impactor serves as a widely used and efficient instrument for aerosol separation. However, the flow field distribution within the microchannel influences the separation curve of the virtual impactor, resulting in an ‘S’-shaped profile rather than the desired step-shaped distribution, which makes achieving 100% particle separation efficiency impractical. Consequently, enhancing the separation efficiency of the separator is crucial in the field of aerosol separation and detection.<h3>Results</h3>We introduce an innovative microseparator, designed on a microfluidic chip, which incorporates an isosceles triangular prism (tri-prism) placed upstream of the nozzle region, thus enhancing the conventional design. This design allows the velocity distribution within both the nozzle and separation regions to transition from a parabolic shape to an M-shape, where the peak velocity shifts from the central axis to the sides, rather than remaining concentrated at the center. The M-shape velocity distribution plays a crucial role in improving the particle collection efficiency. The performance improvement of the proposed microseparator was assessed through numerical simulations and experimental tests, comparing it to the conventional virtual impactor under identical operational conditions and cut-off sizes. As a result, at cut-off sizes of 1.07 <em>μ</em>m and 0.79 <em>μ</em>m, our device showed reductions of 6.14% and 6.698% in the ratio of subcritical particle content to total particle content (<em>C</em>_sp) compared to the conventional virtual impactor, respectively. Additionally, reductions in subcritical particles (<em>R</em>_sp) for the proposed device were 31.37% and 39.32%, respectively.<h3>Significance</h3>The proposed microseparator, based on microfluidic technology, can improve the aerosol separation efficiency. Moreover, its portability and ease of integration provide significant potential for advancing integrated detection systems.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"17 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144334999","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 foodborne Escherichia coli using carbon nanotube-incorporated pencil-drawn paper-based disposable biosensors","authors":"Ozum Ozoglu ,&nbsp;Mihriban Korukluoglu ,&nbsp;Aytekin Uzunoglu","doi":"10.1016/j.aca.2025.344344","DOIUrl":"10.1016/j.aca.2025.344344","url":null,"abstract":"<div><h3>Background</h3><div>In this study, electrochemical flexible paper-based biosensors were developed for rapid and sensitive detection of <em>Escherichia coli,</em> a pathogen and a significant concern in both public health and the food industry. The electrodes were fabricated by a simple pencil drawing method utilizing a commercial, cost-effective cutting tool. Using automated cutting tool to form the conductive graphite patterns enabled the fabrication of pencil-drawn paper-based electrodes with a high reproducibility. The polyclonal <em>E. coli</em> antibody-hybridized multi-walled carbon nanotubes (MWCNTs) were immobilized onto the working electrode surface to construct the biosensors.</div></div><div><h3>Results</h3><div>The performance of the biosensors against <em>E. coli</em> was evaluated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. To the immobilization and performance conditions optimization results, the developed sensor demonstrated the best results at 7.2 pH, 10 μg mL⁻¹ Ab-MWCNT conjugate loadings and 30-min incubation time. The pencil-drawn flexible paper-based biosensors showed a linear range of 10°–10⁷ CFU mL⁻¹ with a low limit of detection (LOD) of 2.6 × 10¹ CFU mL⁻¹. The sensor exhibited high repeatability with a low Relative Standard Deviation (RSD) % of 2.8. The sensors demonstrated remarkable selectivity against various culture environments and good performance in detecting <em>E. coli</em> in apple juices as real samples. In addition, the developed biosensor successfully detected a wild-type <em>E. coli</em> strain which was isolated from a street food and genetically confirmed as <em>E. coli</em> in this study.</div></div><div><h3>Significance</h3><div>Our results suggested that disposable paper-based pencil-drawn flexible electrodes can be used to develop low-cost biosensors with high sensitivity and selectivity against <em>E. coli.</em> To the best of our knowledge, it is the first report using the pencil-drawing method for electrode fabrication for detection of <em>E. coli</em> and its application in real samples.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1369 ","pages":"Article 344344"},"PeriodicalIF":5.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319786","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}