All‐in‐One Zinc‐Doped Prussian Blue Nanozyme for Efficient Capture, Separation, and Detection of Copper Ion (Cu2+) in Complicated Matrixes

Abstract Copper is a vital micronutrient for lives and an important ingredient for bactericides and fungicides. Given its indispensable biological and agricultural roles, there is an urgent need to develop simple, affordable, and reliable methods for detecting copper in complicated matrixes, particularly in underdeveloped regions where costly standardized instruments and sample dilution procedures hinder progress. The findings that zinc‐doped Prussian blue nanoparticle (ZnPB NP) exhibits exceptional efficiency in capturing and isolating copper ions, and accelerates the generation of dissolved oxygen in a solution of H 2 O 2 with remarkable sensitivity and selectivity, the signal of which displays a positive correlation with the copper level due to the copper‐enhanced catalase‐like activity of ZnPB NP, are presented. Consequently, the ZnPB NP serves as an all‐in‐one sensor for copper ion. The credibility of the method for copper assays in human urine and farmland soil is shown by comparing it to the standard instrumentation, yielding a coefficient of correlation ( R 2 = 0.9890), but the cost is dramatically reduced. This ZnPB nanozyme represents a first‐generation probe for copper ion in complicated matrixes, laying the groundwork for the future development of a practical copper sensor that can be applied in resource‐constrained environments.