Construction of CuO/Fe<sub>2</sub>O<sub>3</sub> Nanozymes for Intelligent Detection of Glufosinate and Chlortetracycline Hydrochloride
Mengmeng Sun, Liying Zhao, Tao Liu, Zhiwei Lu, Gehong Su, Wu Chun, Chang Song, Rui Deng, Mingxia He, Hanbing Rao, Yanying Wang
Abstract
In this work, CuO/Fe 2 O 3 nanozymes with high peroxidase-like activity were synthesized by using hydrothermal and calcination methods. The high-resolution transmission electron microscopy (HRTEM) proved that the heterogeneous interface of CuO/Fe 2 O 3 was the main reason for the high enzyme-like activity. Strong interactions of CuO and Fe 2 O 3 were successfully verified by X-ray absorption near-edge structure (XANES) characterization. Experiments and density functional theory (DFT) calculations were also used to explain the increased enzyme activity. The heterogeneous interface acted as the main active center, facilitating the electron transfer from CuO to Fe 2 O 3 . A colorimetric and intelligent sensing system was constructed based on deep learning. Using the peroxidase-like activity of CuO/Fe 2 O 3, a platform for glufosinate pesticides and chlortetracycline hydrochloride (CTC) with the signal “on–off–on” changes were established. The limit of detection (LOD) of glufosinate and CTC was 28 and 0.69 μM, respectively. It was successfully applied in the detection of environmental water and soil. This study can provide an intelligent detection method for environmental monitoring.