Regulatory agencies have identified zineb (ZNB) as a potential health hazard due to its toxicological profile and environmental persistence. Therefore, establishing a highly selective and ultrasensitive method for ZNB detection is crucial for environmental monitoring, food safety assurance, and effective pesticide regulation enforcement. Herein, a selective electrochemical sensor was engineered based on a molecularly-imprinted polymer (MIP) film designed for targeted analyte recognition. The sensing platform integrates bimetallic cobalt–manganese metal–organic frameworks (CoMn-MOFs) with reduced graphene oxide (rGO) to enhance conductivity and surface activity. Initially, GO was synthesized and subsequently reduced to conductive rGO utilizing sodium borohydride via a modified Hummers’ method, forming a high-conductivity matrix for efficient electron transfer. Second, CoMn-MOFs were incorporated to significantly enhance the active surface area and facilitate electron transfer. A selective MIP layer was formed on the electrode surface via electro-polymerization, enabling precise molecular recognition of ZNB. The resulting MIP/rGO/CoMn-MOFs-modified glassy carbon electrode (GCE) exhibited excellent analytical performance, including a broad linear range (0.01–200 nM), a low LOD (4.0 pM), and high selectivity against potential interferents. When applied to real food and water samples, the sensor achieved high accuracy, with recoveries  ranging from 95.5% to 105.6% and RSDs between 1.87% and 4.00%. The method was validated using the standard addition technique, confirming its applicability for accurate ZNB quantification in complex food and water matrices. These findings validate the sensor’s potential as a practical, rapid, and environmentally friendly platform for monitoring ZNB residues in agricultural and environmental contexts.

Rutin is a potent antioxidant with therapeutic value in managing vascular and inflammatory conditions. Its accurate quantification is critical for pharmaceutical quality control and food safety. In this study, rutin was employed as a template to construct surface molecularly imprinted magnetic nanozymes (MIPs@Fe₃O₄–CoNi). These nanozymes retained peroxidase-like activity, catalyzing the H₂O₂-driven transformation of non-fluorescent terephthalic acid into fluorescent 2-hydroxyterephthalic acid. Upon rutin binding, catalytic activity was suppressed, and the fluorescence signal was further quenched through static and inner-filter effects. This dual-signal suppression mechanism significantly enhanced sensor sensitivity. The developed sensing platform exhibited a low detection limit of 0.008 μM and a broad linear range. When applied to pharmaceutical tablets, human serum, and food samples, it achieved recovery rates between 97.5 % and 104.0 %, with RSDs of 2.57 %–4.00 %. These results confirm the method's reliability, precision, and practical applicability across diverse matrices.

Monitoring cefoperazone (CFZ) in milk, serum, and pharmaceutical injections is essential for ensuring consumer safety, proper therapeutic exposure, and product quality. Residue control in milk protects against antimicrobial risks, while serum monitoring prevents toxicity or underdosing. Quality assessment of injections ensures formulation integrity throughout production. In this study, molybdenum–boron/sulfur co-doped carbon dots (Mo/B, N, S@CDs) were synthesized as a fluorescent nanozyme with strong peroxidase-like activity and a photoluminescence quantum yield of 43.55 %. In the presence of H₂O₂, the nanozyme catalyzed the oxidative coupling of 4-aminoantipyrine (4-AAP) with CFZ, producing a red quinoneimine dye with an absorption peak at 515 nm. This enabled colorimetric detection, with absorbance increasing proportionally to CFZ concentration. Concurrently, the dye quenched the green fluorescence of Mo/B, N, S@CDs at 530 nm, providing a sensitive fluorometric mode. The exceptional performance stems from synergistic Mo/B, N, S co-doping, which enhances peroxidase-like activity, optimizes electron transfer, and enables dual-mode signal amplification. Under optimized conditions, the colorimetric and fluorometric methods offered linear ranges of 0.1–500 μM and 0.01–500 μM with detection limits of 0.018 μM and 0.008 μM, respectively. The dual-mode platform performed reliably in milk, serum, and injection samples, yielding recoveries of 98.0–105.7 % and RSDs below 4.00 %, demonstrating its suitability for routine CFZ monitoring.