摘要
The occurrence of pharmaceutical residues,including antibiotic ciprofloxacin(CIP)and the chelating drug D-penicillamine(D-PA),in food and environmental samples has raised increasing concerns regarding food safety and public health.Herein,a bioinspired single-atom copper nanozyme was synthesized via a template-guided strategy by encapsulating sodium copper chlorophyllin(SCC)within zeolitic imidazolate framework-8(ZIF-8).SCC served as a biomimetic precursor,mimicking the active sites of natural oxidase enzymes.Upon pyrolysis,it guided the in-situ formation of atomically dispersed Cu-Nx sites.The resulting nanozyme efficiently catalyzed 3,3′,5,5′-tetramethylbenzidine oxidation and enabled dual colorimetric detection of CIP and D-PA.CIP produced a signal-enhancement response by coordinating with the Cu centers,which facilitated interfacial electron transfer and accelerated the oxidase-like catalytic reaction.In contrast,D-PA induced a signal-suppression response by competitively occupying the Cu active sites through its thiol and amino groups and by reducing oxidized TMB(oxTMB)to its colorless form.Linear detection ranges were 1-7μg/mL for both analytes,limits of detection of 0.097μg/mL for CIP and 0.108μg/mL for D-PA.Recoveries ranged from 94.38%to 103.71%in milk and from 97.73%to 105.18%in river water samples,demonstrating reliable performance in real samples.This work provides a straightforward approach for multi-target colorimetric sensing using Cu single-atom nanozymes,with promising applications in food safety and environmental analysis.
基金
supported by National Natural Science Foundation of China(Grant No.21663017)
Fundamental Research Funds for Inner Mongolia University of Science&Technology(Grant No.2023QNJS020).
