White Nanozymes with Enhanced Alkaline Phosphatase‐Mimicking Activity and Selective Inhibition Effect: Enzyme‐Free Colorimetric Test Strip of Pesticide

Abstract The development of nanozymes with minimized color interference and target‐specific recognition capability represents a critical advancement in colorimetric test strip. Here, white nanozymes are facilely synthesized by coordination polymerization. The optimization of surfactant modification endowed these nanozymes with enhanced alkaline phosphatase (ALP)‐like activity by a larger specific surface area, and electrostatic interactions. Notably, the ALP‐like activity of the nanozyme can be specifically inhibited by emamectin benzoate (EMB) rather than other pesticides. A reversible uncompetitive inhibition mechanism is systematically investigated at both enzymological and molecular levels, establishing a framework for studying nanozyme‐small molecule interactions. Further, an EMB test strip is developed. Crucially, the whiteness of nanozyme effectively minimized nanozyme‐induced background interference and shows a whitening effect on the paper substrate of test strip, significantly enhancing the visibility of colorimetric signal. Due to EMB‐specific recognition, high ALP‐like activity, and the whiteness of nanozyme, the developed nanozyme‐based test strip demonstrated excellent selectivity, high sensitivity, and reliable performance for the real‐time detection in real samples. This work not only demonstrates the seamless integration of white nanozymes with colorimetric test strips, but also provides a promising solution for developing enzyme‐free, visual, and rapid detection platforms by screening highly specific nanozyme recognition elements for commercial pesticides.