Deciphering Pyridinic N−Mediated Inhibition Mode in Platinum Nanozymes for Pesticide Distinction

Abstract Developing high‐performance nanozymes with efficient H ₂ O ₂ activation capacity for biosensing still faces a great challenge. Here, Pt nanoparticles on a porous nitrogen−doped carbon carrier (Pt─N _p ─C) are prepared as efficient nanozymes. By optimizing the pyridinic N content in the carbon carrier, a positive correlation has been found between the pyridinic N content and the peroxidase−like activity of Pt─N _p ─C nanozymes. Additionally, chlorpyrifos, a common pesticide, exerts reversible mixed inhibition on the peroxidase−like activity of Pt─N _p ─C nanozymes, characterized by inhibition constants K _I ′ of 0.180 mM and K _I of 0.147 mM. By combining the inhibition effect with array technology, a three−channel colorimetric sensor array capable of precisely discrimination five pesticides is constructed. The study provides fundamental insights into nanozyme inhibition modes and advanced pesticide sensing applications.