Sensing and Bio-Sensing Research最新文献

{"title":"Electrochemical determination of Pb(II) in paint factory effluent and hot spring water samples using chitosan-based Schiff base modified carbon paste electrode","authors":"Kidus Ayalew Alemu ,&nbsp;Genet Nurga Ansa ,&nbsp;Tolera Marga Goshu ,&nbsp;Mamo Gebrezgiabher ,&nbsp;Siraye Esubalew Debebe ,&nbsp;Tesfu Hailu Halefom","doi":"10.1016/j.sbsr.2025.100928","DOIUrl":"10.1016/j.sbsr.2025.100928","url":null,"abstract":"<div><div>Pb(II) is a hazardous and non-biodegradable metal widely used in paint manufacturing and mining industries, posing health risks such as neurological disorders, kidney dysfunction, and increased blood pressure. Therefore, developing an easy, selective, and sensitive sensor for its detection is crucial. In this study, a chitosan-vanillin Schiff base (CVSB) was synthesized, and its successful formation was confirmed using spectroscopic and electrochemical techniques. Both bare and 10 % CVSB-modified carbon paste electrodes (CVSB-CPE) were employed to detect Pb(II), but the CVSB-CPE demonstrate significant electrocatalytic activity. Using an square wave anodic stripping voltammetry (SWASV) the sensor exhibited a linear response to Pb(II) ranging from 0.001 to 100 μM, with a limit of detection (LOD) of 0.57 nM. Additionally, repeatability tests showed a relative standard deviation (RSD) of 2.6 % over 17 consecutive measurements, while reproducibility across four independently prepared electrodes yielded a RSD of 1.05 %. The sensor also displayed high selectivity in the presence of potential interfering species, including Hg²⁺, K⁺, Cd²⁺, Na⁺, Ni²⁺, Fe³⁺, and Cu²⁺. The recovery tests conducted on factory effluent and hot spring water samples demonstrated a recovery ranging from 97.15 % to 113.49 % and 93.05 % to 108.01 %, respectively.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100928"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomolecule analysis using portable absorption spectrophotometer with novel spatial filter","authors":"Tomoki Tahara ,&nbsp;Mami Akaike ,&nbsp;Yutaro Arakaki ,&nbsp;Kinichi Morita ,&nbsp;Yoichi Saito ,&nbsp;Yoshitaka Nakanishi ,&nbsp;Yuta Nakashima","doi":"10.1016/j.sbsr.2026.100955","DOIUrl":"10.1016/j.sbsr.2026.100955","url":null,"abstract":"<div><div>Biomolecules reflect the onset and progression of disease as well as overall health status, rendering their quantification essential. Although various techniques exist for biomolecule quantification, colorimetric analysis is widely used owing to its simplicity and rapid results. However, conventional absorption spectrophotometers used in such analyses suffer from measurement errors caused by stray light, such as reflected and scattered light, which compromise accuracy. This study introduces a portable absorption spectrophotometer with a novel spatial filter featuring a light-guiding structure designed to suppress stray light. This innovation enables rapid and highly sensitive quantification of biomolecules in the field. Using the proposed device, biomolecular samples including proteins and amino acids were analyzed. The results demonstrated a high linearity in the calibration curve (<em>R</em>² &gt; 0.99), confirming a reliable correlation between absorbance and concentration. Real protein samples, such as serum and immune cells, were quantified with accuracies comparable to those of commercial spectrophotometers, further validating the applicability of the device. These findings highlight the device's potential as an effective tool for biomolecule evaluation in various environments, offering portability, sensitivity, and reliability.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100955"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity-enhanced machine learning–assisted terahertz Plasmonic biosensor using hybrid 2D materials for tuberculosis detection","authors":"K. Rejini ,&nbsp;Humaira Nishat ,&nbsp;P. Manikandan ,&nbsp;P. Ashok ,&nbsp;William Ochen","doi":"10.1016/j.sbsr.2026.100964","DOIUrl":"10.1016/j.sbsr.2026.100964","url":null,"abstract":"<div><div>This work introduces, a machine learning-assisted terahertz metasurface biosensor that integrates graphene, gold, MXene and phosphorene within a single hybrid architecture for tuberculosis detection. Unlike conventional single- or dual-material plasmonic sensors, the proposed design exploits multi-material plasmonic hybridization to simultaneously achieve high sensitivity, angular robustness and tunable electromagnetic response. Finite element method (FEM) simulations in COMSOL Multiphysics are used to systematically optimize the sensor by varying the graphene chemical potential (0.1–0.9 eV), incident angle (0°–80°) and geometric parameters. The optimized design achieves a maximum sensitivity of 1000 GHz/RIU, figure of merit (FOM) of 14.286 RIU⁻¹, quality factor of 10.014 and a detection limit of 0.022 RIU, indicating superior performance compared with conventional THz biosensors. Electromagnetic field analysis reveals strong field confinement and hybridized plasmonic modes within the 0.4–1.8 THz range, with a peak absorption of 76.935% at 80° incidence. A linear resonance frequency–refractive index relationship (R² = 0.98098) confirms reliable quantitative sensing. Furthermore, the incorporation of machine learning–assisted analysis, yielding an R² exceeding 90%, enhances predictive accuracy and robustness. The proposed architecture demonstrates high angular stability, compactness and tunability, establishing its novelty and suitability for point-of-care TB diagnostics and real-time biomedical sensing.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100964"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colorimetric and time-resolved fluorescence lateral flow immunoassays for rapid screening of thrombosis and accurate quantification of D-dimer in human plasma","authors":"Zhenyu Zhou ,&nbsp;Xin'er Hu ,&nbsp;Xinyi Xia ,&nbsp;Meixiang Yu ,&nbsp;Ningqi Xia ,&nbsp;Jiayu Gu ,&nbsp;Yan Cao ,&nbsp;Hai Zhang","doi":"10.1016/j.sbsr.2025.100940","DOIUrl":"10.1016/j.sbsr.2025.100940","url":null,"abstract":"<div><div>D-dimer is a soluble fibrin degradation product, and usually serves as a biomarker for screening and diagnosis of venous thromboembolism (VTE). Immunoturbidimetry is the most commonly used detection method in clinical practice, but it cannot achieve point-of-care testing (POCT) and on-site detection. In this study, two lateral flow immunochromatographic assay (LFIA), colloidal gold lateral flow immunoassay (CG-LFIA) and time-resolved fluorescence microsphere lateral flow immunoassay (TRFM-LFIA), were established for rapid qualification and accurate quantification of D-dimer in human plasma. Both analytical methods were rapid, simple, and capable of on-site monitoring without complex sample pretreatment. The CG-LFIA achieved rapid qualitative assessment based on the visible color intensity of the strips and on-site quantitative detection through strip image scanning. Compared with CG-LFIA, the TRFM-LFIA can provide a wider dynamic range and superior sensitivity for D-dimer detection, although it does not allow for rapid qualification. After systematic optimization and rigorous methodological validation, the detection limit of CG-LFIA was 40 ng/mL with a dynamic range of 40–1280 ng/mL, while TRFM-LFIA had a lower detection limit of 6.1 ng/mL and a wider dynamic range of 10–2000 ng/mL. Both methods demonstrated excellent consistency in detecting D-dimer in human plasma in comparison with immunoturbidimetry. Therefore, CG-LFIA is more suitable for rapid on-site screening of clinical thrombosis patients preliminarily, while TRFM-LFIA is more appropriate for rapid and accurate POCT quantification of D-dimer in human plasma. Both methods will provide more convenient testing services for clinical thrombus screening and thrombus progression assessment.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100940"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microfluidic platform combined with a dark field imaging system for quantification of E. coli contamination in water","authors":"Anna Malec ,&nbsp;Christoph Haiden ,&nbsp;Georgios Kokkinis ,&nbsp;Ioanna Giouroudi","doi":"10.1016/j.sbsr.2025.100945","DOIUrl":"10.1016/j.sbsr.2025.100945","url":null,"abstract":"<div><div>In this paper, we present a method for detecting and quantifying pathogens in water samples. The method proposes a portable dark field imaging and analysis system for quantifying <em>E. coli</em> concentrations in water after being labeled with magnetic particles. The system utilizes the tracking of moving micro/nano objects close to or below the optical resolution limit confined in small sample volumes (∼ 10 μl). In particular, the system analyzes the effect of volumetric changes due to bacteria conjugation to magnetic microparticles (MP) on their Brownian motion while being suspended in liquid buffer solution. The method allows for a simple inexpensive implementation and the possibility to be used as point-of-need testing system. Indeed, a working prototype is demonstrated with the capacity of quantifying <em>E. coli</em> colony forming units (CFU) at a range of 1 × 10³ - 6 × 10³ CFU/mL.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100945"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical design of a Kretschmann-configured multilayer SPR sensor with bismuth germanate dielectrics for high-sensitivity non-invasive glucose monitoring in diabetes management","authors":"R. Sathiya ,&nbsp;Nitin Lingayat ,&nbsp;S. Gopinath ,&nbsp;Harishchander Anandaram ,&nbsp;U. Arun Kumar","doi":"10.1016/j.sbsr.2026.100996","DOIUrl":"10.1016/j.sbsr.2026.100996","url":null,"abstract":"<div><div>Blood glucose monitoring is essential for effective diabetes management, as well as for early screening and detection of glycemic abnormalities. However, conventional techniques suffer from limitations, which includes invasiveness, enzyme instability, and delayed physiological response. This study introduces a Kretschmann-based multilayer surface plasmon resonance (SPR) glucose sensor that operates through label-free refractive index modulation rather than enzymatic electrochemical detection. The device has a BK-7 prism substrate, a silver (Ag) plasmonic layer, and dielectric layers of bismuth germanate (Bi₁₂GeO₂₀) and bismuth germanium oxide (Bi₄Ge₃O₁₂), and it functions at 633 nm. In order to minimize reflectance and enhance electric field confinement at the sensor interface, the transfer matrix approach was used to optimize the thickness of the layers. With optimized layer thicknesses of 50 nm (Ag), 0.3 nm effective optical thickness (Bi₄Ge₃O₁₂), and 2 nm (Bi₁₂GeO₂₀), the design achieves a theoretical minimum reflectance of 0.007%. The sensor exhibits a peak local differential sensitivity of 250°/RIU, a quality factor of 14.415, and a figure of merit of 47.17 RIU⁻¹ The resonance angle exhibits a strong linear dependence on refractive index (R² = 0.9977), described by θ (°) = 177.04 RI − 162.08, corresponding to a global sensitivity of 177.04°/RIU. This enables accurate glucose quantification over physiological refractive index ranges (1.335–1.347 RIU), relevant to diabetes screening and non-invasive glucose detection applications. Electric field analysis shows enhancement up to 15.5 × 10⁴ V/m at 74.7°, indicating strong evanescent field interaction with the sensing medium. Comparative analysis with existing SPR sensors shows competitive performance while maintaining structural simplicity. The proposed multilayer SPR configuration provides a high-sensitivity refractive-index sensing platform suitable for non-invasive glucose screening, early detection, and monitoring in diabetes management. This work represents a numerical proof-of-concept, and experimental validation under physiologically relevant conditions will be required to establish clinical applicability.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100996"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147421385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous and ultrasensitive detection of HBV DNA and RNA in CHB by utilizing Cas12a/Cas13a-based dual-target strategy","authors":"Yuanyuan Li ,&nbsp;Yuxin Liu ,&nbsp;Lijuan Wu ,&nbsp;Yueyue Chen ,&nbsp;Mengchun Wang ,&nbsp;Hongchun Luo ,&nbsp;Juan Chen ,&nbsp;Yuan Hu","doi":"10.1016/j.sbsr.2025.100925","DOIUrl":"10.1016/j.sbsr.2025.100925","url":null,"abstract":"<div><div>Simultaneous detection of low levels of serum HBV DNA plus RNA in HBV-infected patients receiving antiviral therapy is an effective strategy to evaluate the antiviral effect. In this research, we established an ultrasensitive dual PCR-CRISPR fluorescent assay (DPCFS) based on CRISPR-Cas12a/Cas13a system to simultaneous detection of low levels of HBV DNA and RNA. We optimized the DPCFS assay and evaluated the specificity and sensitivity employing the HBV plasmid. Clinical validation and comparison with commercial HBV DNA ultrasensitive qPCR assay or reverse transcription droplet digital polymerase chain reaction (RT-ddPCR) were conducted using 46 serum samples of HBV-infected patients including 22 treatment-naïve and 24 nucleotide/nucleoside analogs (NAs)-treated patients. The limit of detection (LOD) for DPCFS platform was 5.8 copies/μL HBV DNA and 1.4 copies/μL HBV RNA, respectively, and the detection results could be directly visible to the naked eye under blue light without the need for any specialized instruments. Furthermore, clinical validation has 97.06 % sensitivity and 100 % specificity compared with commercial HBV DNA ultrasensitive qPCR assay. For serum HBV RNA detection, the sensitivity of DPCFS assay was 86.84 %, and the specificity was 87.5 % compared with RT-ddPCR. We developed a simultaneous and ultrasensitive detection of lower levels of HBV DNA and RNA in HBV-infected patients receiving antiviral therapy, which provide more accurate and simple strategy to evaluate the antiviral effect and treatment guidance.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100925"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145622898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-sensitivity photonic crystal fibre biosensor for malaria detection","authors":"Shuvo Sen ,&nbsp;Mohammad Abdullah-Al-Shafi ,&nbsp;Mashiyat Mubassera ,&nbsp;Md. Tanvir Hossain Hawlader","doi":"10.1016/j.sbsr.2026.100963","DOIUrl":"10.1016/j.sbsr.2026.100963","url":null,"abstract":"<div><div>Malaria continues to threaten global health, demanding rapid and reliable diagnostic methods. Traditional techniques often lack sensitivity or speed, underscoring the need for advanced sensing approaches. This study proposes a photonic crystal fibre (PCF)-based sensor engineered for precise malaria detection. The sensor features five layers of heptagonal cladding and a central hollow core designed for red blood cell (RBC) infiltration, enabling intense light-matter interaction. By tracking refractive index shifts, it distinguishes Ring, Trophozoite, and Schizont stages through wavelength variations, offering accurate, label-free, real-time diagnosis. A comprehensive analysis of the fibre's geometry, material composition, and mode properties is conducted to optimise its detection capabilities. The sensor operates within a refractive index range of 1.33 to 1.41, making it suitable for identifying malaria-infected RBCs. Comprehensive numerical analysis demonstrates that the proposed fibre exhibits exceptionally high sensitivity across the different developmental stages of the parasite. The relative sensitivity (RS) is recorded as 97.40% for the regular stage (<em>n</em> = 1.402), 96.90% for the ring stage (<em>n</em> = 1.395), 96.20% for the trophozoite stage (<em>n</em> = 1.383), and 95.40% for the schizont stage (<em>n</em> = 1.373). In parallel, the confinement loss (CL) remains remarkably low, measured as 6.08 × 10⁻⁸ dB/m for the regular stage, 5.98 × 10⁻⁸ dB/m for the ring stage, 5.90 × 10⁻⁸ dB/m for the trophozoite stage and 5.85 × 10⁻⁸ dB/m for the schizont stage at the monitoring frequency of 2.2 THz. These findings underscore the potential of PCF sensors as a highly efficient and cost-effective diagnostic platform for malaria. By offering both superior sensitivity and minimal signal loss, this work paves the way for significant advancements in early disease detection and improved public health outcomes.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100963"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new rGO@Ni nanocomposite for simultaneous detection of Pb (II) and Cd (II)","authors":"Ana Ameda ,&nbsp;Lueda Kulla ,&nbsp;Alma Shehu ,&nbsp;Besnik Baraj ,&nbsp;Sadik Cenolli ,&nbsp;Nevila Broli ,&nbsp;Majlinda Vasjari","doi":"10.1016/j.sbsr.2026.100951","DOIUrl":"10.1016/j.sbsr.2026.100951","url":null,"abstract":"<div><div>Heavy metals (HMs) are recognised as major environmental pollutants due to their high toxicity, persistence, and tendency to bioaccumulate in ecosystems. Due to their high accuracy, rapid analysis, and excellent sensitivity, electrochemical detection methods have garnered considerable interest. The focus of this work is to develop a sensitive, selective, and fast electrochemical sensing platform suitable for on-site monitoring of heavy metals. By combining the advantages of graphene oxide and metal nanoparticles, a carbon-based sensor was prepared by integrating reduced graphene oxide with nickel nanoparticles (rGO@Ni) to enhance the detection of Pb(II) and Cd(II) ions. The electrochemical performance of the CPE/rGO@Ni sensor was evaluated using cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The results demonstrate that incorporating nickel nanoparticles into the graphene matrix significantly improves the electrochemical response toward Pb (II) and Cd (II), both in individual and simultaneous detection. The rGo@Ni nanocomposite enables the resolved and concurrent determination of Pb (II) and Cd (II) with minimal mutual interference, highlighting its suitability for multi-ion analysis. The sensor exhibits limits of detection of 0.039 ppm for Pb (II) with a sensitivity of 533.7 μAppm⁻¹, and 0.012 ppm for Cd (II) with a sensitivity of 273.75 μAppm⁻¹ in single ion analysis. Although the detection limits fall within the ppm range, the ability of the rGo@Ni nanocomposite to maintain stable and distinguished signals in the presence of coexisting ions represents a significant advantage for practical applications. These features indicate promising potential for integration into printed sensing technologies, which may help mitigate the challenges associated with ppm-level detection and further improve analytical performance.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100951"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ratiometric fluorescence nanosensor based on CER-assisted CdTe quantum dots for therapeutic drug monitoring of methotrexate","authors":"Qiongdan Zhang ,&nbsp;Ziyi Zhou ,&nbsp;Huihong Duan,&nbsp;Kang Long,&nbsp;Qiqi Han,&nbsp;Wei Wang,&nbsp;Bin Li","doi":"10.1016/j.sbsr.2026.100967","DOIUrl":"10.1016/j.sbsr.2026.100967","url":null,"abstract":"<div><div>Methotrexate (MTX) is a cornerstone chemotherapeutic agent with a narrow therapeutic index, making therapeutic drug monitoring (TDM) essential to optimize efficacy and prevent severe toxicity. While existing techniques like HPLC and ELISA offer high sensitivity, their complexity, cost, and time requirements can limit rapid clinical decision-making. To address the need for a practical and robust alternative, we developed a novel dual-emission ratiometric fluorescent nanosensor (DERFN) based on cation-exchange reaction (CER)-enhanced CdTe quantum dots. This design prioritizes operational simplicity, rapid analysis, and resilience to matrix interference, achieving reliable MTX detection in the clinically critical concentration range. The sensor exhibits a wide linear response from 0.2 to 120 μM, with a detection limit of 3.75 μM in human serum and excellent recovery rates (100.37–110.71%). While not targeting sub-nanomolar levels required for delayed clearance monitoring, the CER-assisted DERFN platform demonstrates high selectivity, stability, and practicality. It thus presents a promising complementary tool for rapid MTX level assessment in settings where speed, cost-effectiveness, and ease of use are paramount.</div></div>","PeriodicalId":424,"journal":{"name":"Sensing and Bio-Sensing Research","volume":"51 ","pages":"Article 100967"},"PeriodicalIF":4.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146034496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}