Development of a Zr/Fe-MIL nanozyme sensor integrated with a user-friendly colorimetric device for glyphosate monitoring

Abstract

Timely and efficient analysis of glyphosate (GLP) in agriculture and environment is critical for food safety and public health. Herein, a paper-based enzyme sensor integrated with a portable device for GLP monitoring was developed. First, zirconium ions were doped into a typical iron-based MOF (Fe-MIL) via a simple solvothermal method, yielding a Zr/Fe-MIL composite that exhibits remarkable peroxidase-like activity. Zr/Fe-MIL had the capability to sensitively detect GLP, and the sensing mechanism was attributed to the coordination, hydrogen bonding and electrostatic interactions between Zr/Fe-MIL and GLP. Subsequently, a test strip combined with a portable device was designed to integrate automatic extraction, collection, and processing of colorimetric signals, enabling rapid signal analysis and direct concentration output. This system achieved linear ranges of 0.1–1 μg mL⁻¹ and 1–10 μg mL⁻¹, with a low limit of detection (LOD) of 29.1 ng mL⁻¹. The proposed strategy could also be applied to water and food samples (sorghum and soybean) with the recovery rates of 98.53–112.94%. This work provides an effective strategy for the development of portable and user-friendly methods for monitoring GLP.