Two‐Dimensional Nitrogen‐Doped Ti₃C₂ Promoted Catalysis Performance of Silver Nanozyme for Ultrasensitive Detection of Hydrogen Peroxide

Abstract Silver nanoparticles (AgNPs)‐based nanozyme sensors are gaining attention for rapid on‐site H 2 O 2 detection, which is beneficial to disease diagnosis and environmental monitoring. However, the severe agglomeration of AgNPs on the electrodes significantly reduced electrochemical catalytic activity. In this work, we fabricated N‐doped Ti 3 C 2 MXene (named Ag/N−Ti 3 C 2 ) deposited with three‐dimensional flower‐like AgNPs to achieve ultrasensitive H 2 O 2 detection. N doping strategy is employed to improve the conductivity of MXene, and the corresponding catalytic activity of Ag/N−Ti 3 C 2 is enhanced by optimizing the growth process and morphology. The Ag/N−Ti 3 C 2 /glassy carbon electrode (Ag/N‐Ti 3 C 2 /GCE) sensor exhibited a wide H 2 O 2 detection range (0.05–35 mM), a low limit detection (1.53 μM), and 3.1 % relative standard deviation in 50 repeated cyclic voltammetry measurements. The results above indicate that catalytic activity of metal nanozymes could be influenced by the substrate and both materials jointly determine the sensor's performance. As a result, N‐doped MXene is an attractive candidate for biological sensing and other electrocatalytic applications.