Aug 2026· Analytical Chemistry· Vol 98 32, pp.
23554-23571
· 0 citations· 38 references
Medicine
Abstract
Reliable sulfide analysis in complex matrices remains challenging because single-signal probes are susceptible to interference and ambiguous readouts. Here, we report a tetrazine-metal-polyphenol nanoprobe, RhB@Tz-MPN, for a single-tube sequential multimodal workflow for sulfide analysis. Sulfide produces three role-differentiated responses: a tetrazine-associated UV-vis blue shift for rapid screening, fluorescence recovery accompanying framework reorganization for quantitative readout, and suppression of peroxidase-like activity as a substrate-dependent cross-checking signal. All three readouts are obtained sequentially from the same sample tube, reducing sample transfer and intertube variation. Exploratory residual analysis showed a low observed residual correlation between the two direct optical channels (r = 0.06), while the nanozyme response was more appropriately treated as a sequential cross-checking readout. Under the acidic workflow condition, the fluorescence channel showed a linear range of 5-50 μM with an LOD of 0.79 μM. Spike-and-recovery experiments in tap water and lake water gave recoveries of 102.50-118.16% with RSDs below 4%. The platform also responded to stimulation-induced, cell-associated H2S generation in HepG2 cells and differentiated accumulated spoilage-associated headspace exposure from pork. This work establishes a role-differentiated single-tube strategy for integrating screening, quantification, and cross-checking in sulfide analysis.
Nanoplastics (NPs) are new types of pollutants that have emerged in food which has attracted widespread attention. However, due to the small size and low concentration, and the complexity of food matrices, the selective and sensitive determination of NPs in food is challenging. Herein, we report a dual-probe system for determination of trace-level polystyrene (PS) NPs with high sensitivity and selectivity. The proposed dual-probe system was composed of magnetic Fe3O4 nanoparticles functionalized with PS-specific peptides (Fe3O4@Au-PSBP) and a high-quality Li+-doped ZnGa2O4:Cr3+ persistent luminescence nanoparticles (PLNPs) modified with ethylene glycol chitosan. By integrating peptide-based specific recognition, persistent luminescence signaling, and magnetic separation with pH-switchable charge reversal, the proposed system enables effective capture and sensitive detection of PS NPs in complex matrices. Under the optimized conditions, the method showed a linear range of 50–800 pg mL−1 and a detection limit of 8.11 pg mL−1. The precision for the determination of 50 pg mL−1 PS NPs was 5.24% (RSD, n = 11). The method was successfully applied to the analysis of PS NPs in different matrices, including bottled purified water, saltwater (3.5% salinity), artificial lake water, and tea beverage, with recoveries ranging from 91.25% to 110.53%. More importantly, the proposed system can be readily adapted for the analysis of other targets by replacing the recognition unit, providing a versatile and selective sensing strategy for trace-level hazardous analytes.
Beibei Wang, Ling Sun, Kai Liu et al.· Current Research in Food Sci...· 0 citations
Precise quantitative monitoring of 17β-estradiol (E2) is important for reproductive management in precision livestock farming. However, E2 determination in complex biological matrices remains challenging because of matrix-derived background and signal variability. Here, we developed a nanoconfinement-assisted solid-state ratiometric fluorescent aptasensor integrating target-induced strand displacement (TISD), magnetic separation, and anodic aluminum oxide (AAO) nanochannel confinement. The sensing probe consisted of streptavidin-coated magnetic nanoparticles (MNPs) carrying a FAM-labeled cDNA internal reference and a Texas Red-labeled E2 aptamer reporter. E2 binding promoted dissociation of the Texas Red-labeled aptamer from the magnetic probe. Magnetic separation and washing reduced soluble matrix-derived interference, while subsequent deposition of the sensing complexes onto an AAO membrane mitigated coffee-ring-associated nonuniformity and produced a more spatially uniform dual-color fluorescence distribution for ratiometric analysis. Under matrix-matched calibration conditions, linear ranges of 5.0–50.0 pM were obtained in tap water and sow saliva, 5.0–40.0 pM in whole milk, and 5.0–15.0 pM in post-estrus sow urine. The LOD determined in tap water was 3.62 pM. The different calibration slopes obtained among the four matrices indicated that residual matrix-dependent effects remained and that matrix-specific calibration was required for quantitative analysis. Matrix-matched spike recoveries ranged from 86.92% to 119.54% across the investigated matrices. The aptasensor exhibited the strongest response toward 17β-E2 among the tested compounds; however, cross-reactivities of 77.3% for E3 and 47.3% for 17α-E2 indicated preferential rather than exclusive recognition. Molecular docking suggested a putative binding pose but did not experimentally establish the molecular recognition mechanism. Overall, the platform demonstrated laboratory-scale analytical feasibility in pretreated tap water, sow saliva, whole milk, and post-estrus sow urine. Further development of sample preparation, magnetic handling, membrane loading, probe selectivity, and portable fluorescence readout will be required before in situ or on-site application.
Thiamethoxam, a widely utilized neonicotinoid insecticide, has been extensively applied in agricultural practices, leading to various adverse effects on human health, such as neurotoxicity, developmental issues, and endocrine disruption. Therefore, establishing a comprehensive and standardized surveillance framework for the quantitative determination of thiamethoxam residues in environmental compartments and food matrices is critical for mitigating its chronic toxicological risks to human health. We developed a biosensor for thiamethoxam detection, which leverages the target-induced formation of G-quadruplexes and subsequent Thioflavin T fluorescence enhancement based on Exonuclease III-driven shear amplification and the hybridization chain reaction. Under optimized conditions, this biosensor exhibited a detection range from 10 pg mL-1 to 1 µg mL-1 and a detection limit of 8.7 pg mL-1. Furthermore, the successful detection of thiamethoxam in real samples confirms the biosensor's practical applicability and reliability.
Early and multiplex detection of Alzheimer’s disease (AD) biomarkers is essential for timely diagnosis and accurate disease staging; however, conventional immunoassays lack the sensitivity and multi-channel capability required to quantify extremely low-abundance proteins in complex biological matrices. In this work, we present a novel triple-target electrochemiluminescence (ECL) biosensor based on magnetic metal–organic frameworks (MMOFs) integrated with quantum-dot (QD)–mediated resonance energy transfer (RET) for the simultaneous detection of three clinically significant AD biomarkers: Amyloid Precursor Protein (APP), Clusterin, and Glial Fibrillary Acidic Protein (GFAP). The MMOF platform provides a high-surface-area, magnetically responsive scaffold that enables efficient immobilization of primary antibodies, while MoS₂ QDs, carbon quantum dots (CQDs), and CdSe/ZnS QDs act as spectrally distinct RET acceptors, facilitating clean and interference-free multiplexed ECL readout from a single TCPO-triggered excitation event. Under optimized analytical conditions, the biosensor displayed strong, concentration-dependent ECL responses across a wide dynamic range (40 ng/mL down to 0.0004 ng/mL). The calculated limits of detection demonstrated excellent sensitivity, achieving 0.67 pg/mL for APP, 0.92 pg/mL for Clusterin, and 0.54 pg/mL for GFAP, confirming the platform’s capability to quantify trace-level biomarkers far below their physiological concentrations. This remarkable performance arises from the highly efficient CRET mechanism between TCPO high-energy intermediates and the QD emitters, further enhanced by the synergistic dual co-reactant system (H₂O₂/APS).
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Muhammad Faizan, Chi-Hsien Liu· ECS Meeting Abstracts· 0 citations
Detection of 3-MCPD in lipid-rich food matrices remains challenging due to trace analyte levels, high viscosity, and severe matrix interference. Herein, a photothermal-driven magnetic "three-in-one" sensing platform based on L-cysteine-functionalized ZnFe2O4 (L-ZFO) nanoparticles was developed for rapid and sensitive screening of 3-MCPD in edible oils. The multifunctional platform integrates magnetic enrichment, photothermal-assisted signal amplification, and colorimetric sensing, enabling efficient extraction and detection with minimal sample pretreatment. Benefiting from the synergistic interfacial enrichment and photothermal enhancement, the proposed method exhibited a linear range of 0.01-0.20 mg/L with a low detection limit of 1.4 μg/L. The platform showed acceptable recoveries of 75.0-92.0% and relative standard deviations below 5.8% in edible oil samples. Moreover, comparable responses obtained in buffer and oil matrices demonstrated excellent anti-interference capability toward complex lipid systems. The recyclable L-ZFO probe also exhibited good stability and reproducibility over 3 cycles. This work provides an elimination of pretreatment strategy for rapid on-site screening of 3-MCPD in edible oils.
Chenxi Liu, Jihan Huang, Sinuo Cheng et al.· Journal of Hazardous Materia...· 0 citations
This review examines recent advancements (2016–2025) in azo-based chemosensors for detecting metal ions, anions, and small molecules. A total of 52 structurally diverse probes were analysed and categorised into single-analyte and multi-analyte systems and assessed using a designed scoring framework across four dimensions: aqueous compatibility, selectivity rigor, real-sample validation, and deployment readiness. The field has evolved from simple colorimetric dyes in organic media to scaffolds incorporating heterocyclic receptors, rhodamine spirolactams, and displacement assays, achieving nanomolar detection limits and validation in real environmental and biological matrices. Model studies, such as sensors 3 and 4 (which contain water-solubilising moieties) and sensor 44 (a commercial dye-based indicator displacement probe), set standards for rigour and translational potential. However, persistent limitations hinder widespread utility: over 70% of sensors depend on organic co-solvents, interference studies are often incomplete, real-sample validation is insufficient, and synthetically complex designs impede scalability. Future directions, including water-compatible designs, displacement assays, reusable solid-state platforms, and the repurposing of commercial dyes, offer a pathway to transform proof-of-concept into field-deployable, sustainable sensing solutions.
S. O. Olaleye, D. T. Ajayi· RSC Advances· 0 citations
