Copper-metalated COFs with oxidase-like activity for colorimetric glyphosate monitoring on a handheld device

Abstract

Glyphosate (GLY) as pesticide is extensively utilized in farming, and excessive residues in food have serious toxicity to hum ans. Monitoring of GLY is essential for upholding food safety, public health, and ecosystem well-being. Herein, copper-base d covalent organic frameworks (Cu@COFs)-based nanozymes were designed to construct a colorimetric strategy for GLY m onitoring. Cu@COFs were fabricated using a straightforward one-pot approach to serve as oxidase mimics for 3, 3', 5, 5'-te tramethylbenzidine (TMB) companied with H 2 O 2 . In the detection system, upon the introduction of GLY, Cu@COFs-based d etecting system presented a low-intensity color response due to the coordination between GLY and Cu ions of Cu@COFs. T he colorimetric platform demonstrated a low detection limit (LOD) of 0.5 mg/L, with dual linear ranges of 0.5-7 mg/L and 10-100 mg/L, along with excellent sensitivity and selectivity. The proposed sensing platform were utilized to monitoring th e foods containing GLY, including tea, corn, and soybean. Meanwhile, a smartphone-compatible handle device was fabricat ed for portable, real-time, and user-friendly GLY detection in field settings. Our detection platform provided a promising pr ospect for application.