A Colorimetric Sensor Enabled with Heterogeneous Nanozymes with Phosphatase-like Activity for the Residue Analysis of Methyl Parathion

Abstract

In this study, a colorimetric sensor was developed for the detection of organophosphorus pesticides (OPs) using a heterogeneous nanozyme with phosphatase-like activity. Herein, this heterogeneous nanozyme (Au-pCeO2) was obtained by the modification of gold nanoparticles on porous cerium oxide nanorods, resulting in synergistic hydrolysis performance for OPs. Taking methyl parathion (MP) as the target pesticide, the catalytic performance and mechanism of Au-pCeO2 were investigated. Based on the phosphatase-like Au-pCeO2, a dual-mode colorimetric sensor for MP was put forward by the analysis of the hydrolysis product via a UV-visible spectrophotometer and a smartphone. Under optimum conditions, this dual-mode strategy can be used for the on-site analysis of MP with concentrations of 5 to 200 μM. Additionally, it can be applied for MP detection in pear and lettuce samples with recoveries ranging from 85.27% to 115.87% and relative standard deviations (RSDs) not exceeding 6.20%, which can provide a simple and convenient method for OP detection in agricultural products.

Nanozymes: powerful catalytic materials for environmental pollutant detection and degradation

“…According to the role of pesticides in the nanozyme-only sensors, they can be classified into two kinds: (1) pesticide molecules induce the variation of nanozyme activity via their specific interactions; 178–182,192–196 (2) OPs are hydrolyzed by phosphatase-mimetic materials to produce response. 186–189…”

“…Apart from the common peroxidase- and oxidase-mimetic features of nanozymes for pesticide analysis, nanoscale materials with phosphatase-mimicking catalytic capacity have also been studied, which can break the phosphoester bond in OPs. 186–189 In these methods, OPs act as a reactant to produce response. The typical phosphatase-mimicking nanozymes include Zr- and Ce-based materials.…”

Rational Integration of Nanozyme Probe and Smartphone Device for On‐Site Analysis

“…Inevitably, pesticide residues cause a series of living organisms and environmental pollution problems, necessitating the development of rapid and sensitive selective detection methods. [153][154][155] As we all know, organophosphorus pesticides ensure the growth of crops via inhibiting the activity of AChE and killing insects. According to this, Niu et al prepared an all-in-one test strip by assembling all the sensing elements together, including TMB, Hemin, BSA, AChE and CHO.…”

“…H 2 O 2 substrate was also not required in this sensing platform, offering a rapid and environment-friendly approach for the detection of pesticide residues in agricultural products. [159] As one of the most basic raw materials of the organic chemical industry, phenolic compounds have become the second most familiar pollutants owing to their high watersolubility. To find satisfactory green catalysts for removing and monitoring phenolic pollutants, He et al prepared an amorphous imidazole-Cu nanozyme (IÀ Cu) to mimic laccase activity and catecholase activity for on-site monitoring pharmaceutical pollution in rivers.…”