G-quadruplex-based fluorescent sensing platform for thiamethoxam detection: integrating multiple signal amplification strategies.

Field-deployable supramolecular fluorescent sensing platform for selective dual-mode detection of thiamethoxam in complex environmental matrices

Integrated Colorimetric/Fluorescence Nanozyme Dual-Signal Probe for Simultaneous Detection and Degradation of Organophosphorus Nerve Agents.

A 3D-bioprinted biosensor for on-site sulfamethazine monitoring complemented by in silico analysis of its thyroid neoplasms toxicity mechanism

Sensitive Detection of Biomarker Using Multifunctional Aptamer-Modified Fluorescent E. coli O157:H7

Highly sensitive quantification of biomarkers is essential for disease diagnosis, treatment monitoring, and prognosis evaluation. Recently, nanomaterial-based immunosensors have attracted increasing attention due to their high sensitivity. However, the preparation of nanomaterials is often complex, costly, and environmentally unfriendly. Here, we employed Escherichia coli O157:H7 as a nanoreporting probe, leveraging its dyeable genomic DNA to achieve direct signal amplification of target biomarkers. A multifunctional hairpin-shaped aptamer was designed to convert the target into measurable fluorescence signals from E. coli O157:H7 through bispecific binding and allosteric effects of the aptamer. Under optimized conditions, the E. coli O157:H7-based biosensor could detect 0.05 pg/mL prostate-specific antigen (PSA), with a linear relationship ranging from 0.1 to 50 pg/mL (correlation coefficient R2 = 0.988). The method also demonstrated excellent specificity and recovery rates (93–107%), confirming its applicability for real-sample detection. A small-scale clinical study illustrated that the serum PSA levels were significantly elevated in patients with polycystic ovary syndrome compared to healthy controls. Hence, low-abundance PSA analysis may expand the utility of PSA in female-related diseases.

Label-free and enzyme-free fluorescent biosensor for ultrasensitive detection of tobramycin via cascade signal amplification.

Uncontrolled use of tobramycin (TOB) raises serious health concerns, including nephrotoxicity and ototoxicity, making it imperative to develop simple and sensitive detection methods. This study introduces a novel enzyme-free and label-free fluorescent biosensor based on a cascade signal amplification strategy, integrating an entropy-driven DNA circuit (EDC) with catalytic hairpin assembly (CHA). The mechanism is initiated by the specific binding of TOB to its aptamer, which induces a conformational change and exposes a priming sequence. This sequence triggers a strand displacement reaction to release an initiator strand, subsequently activating the CHA process to generate fuel strands. These fuel strands drive the EDC, resulting in the liberation of numerous G-quadruplex sequences from the stem of hairpin probes. The released G-quadruplexes bind to thioflavin T (ThT), yielding a significantly enhanced fluorescence signal proportional to the TOB concentration. The proposed biosensor exhibits outstanding analytical performance with a detection limit of 92 fM and a wide linear range from 3 pM to 30 nM. Furthermore, the method effectively distinguishes TOB from other interfering antibiotics, highlighting its high specificity. It also demonstrates practical applicability by achieving satisfactory recovery rates in milk sample assays. With its high sensitivity, cost-effectiveness, and operational simplicity without the need for complex enzymes or labels, the proposed strategy offers a promising platform for food safety supervision and clinical diagnostics.

Nanomaterial-enabled sensing of paraquat in food and environmental matrices: mechanisms, materials, and analytical challenges.

Paraquat (PQ), a highly toxic herbicide banned in several countries yet still widely used globally, poses severe threats to human health and ecosystems through acute poisoning and chronic exposure via contaminated food and water. Despite numerous analytical methods, rapid, sensitive, and field-deployable detection remains essential for effective monitoring and regulatory enforcement. Unlike existing reviews focusing narrowly on specific nanomaterials or detection techniques, this review represents a systematic cross-platform comparison evaluating metallic nanoparticles (Au, Ag, Pt), carbon-based materials (graphene, carbon nanotubes, quantum dots), metal-organic frameworks, and hybrid nanocomposites across electrochemical detection mechanisms. Critically, this review examines how food and environmental matrix effects influence sensor performance and discusses the analytical validation requirements necessary for reliable paraquat determination, thereby addressing a major gap in studies that predominantly report performance under idealized buffer conditions. Novel enhancement strategies are evaluated, including molecularly imprinted polymers, aptamer functionalization, and disposable electrode integration for point-of-use testing. This review uniquely addresses the translational research gap by identifying why promising laboratory sensors fail in real-world applications, including challenges associated with matrix interference, selectivity, long-term stability, reproducibility, and practical validation based on reports over the past decade. Furthermore, economic feasibility and lifecycle aspects of nanomaterial-enabled sensing platforms are critically discussed to evaluate their potential for deployment in resource-limited settings. Thus, the review provides clear guidance for developing next-generation sensors capable of protecting public health through effective paraquat monitoring.