Competitive difference-driven Ag@Pt nanozyme on a single gold nanowire sensing platform integrated with machine...

The wide use of tetracycline antibiotics (TCs) exists serious public safety concern for human health due to their accumulation in foods and environments. Meanwhile, various kinds of TCs are frequently present simultaneously in practical environments, it is vital to come up with innovative solutions for high-sensitivity detection and accurate identification. Herein, a novel strategy of competitive difference-driven Ag@Pt nanozyme on a single gold nanowire (Au NW) sensing platform was developed for accurate identification of multiple TCs. Hollow dendritic Ag@Pt nanoparticles (NPs) with peroxidase-like (POD-like) activity have been synthesized and can decompose H₂O₂ to produce reactive oxygen species (ROS), which subsequently oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into oxidized TMB (ox-TMB). In the presence of both TCs and TMB, a competitive reaction with ROS occurs, attenuating the extent of TMB oxidation. Building on this, this platform integrates surface-enhanced Raman scattering and electrochemical (SERS/EC) techniques and further combines them with machine learning to achieve ultrasensitive quantitative detection and accurate identification of five TCs, including minocycline (MC), tetracycline (TET), oxytetracycline (OTC), chlortetracycline (CTC), and doxycycline (DOX). It enables accurate detection of various targets at low concentrations ranging from 2 × 10^-5 ppm to 2 × 10^-2 ppm, with a detection limit as low as 3.54 × 10^-7 ppm for MC. This study combines efficient catalytic activity of nanozymes, the significant advantages brought by the miniaturization of the single Au NW platform, and the structural differences among various TCs, offering significant application value for the rapid, direct, and simultaneous detection of multiple hazards in the environment and food chain.