A portable kit for high-throughput determination of methyl parathion on vegetable surface by integrating solid-phase microextraction and surface-enhanced Raman spectroscopy.

A portable kit was developed for on-site high-throughput detection of methyl parathion (MPT) in vegetables by integrating solid-phase microextraction and SERS technology. This portable kit consists of a 96-well plate coated with a copper foil modified by silver nanocrystals, which was fabricated by a galvanic displacement method. The 96-well plate allows multiple samples to be pretreated simultaneously, with each well featuring small pits that isolate individual samples, effectively preventing cross-contamination. Furthermore, the SERS substrate allows the enrichment of MPT on its surface, enhancing detection sensitivity and specificity. The method detection limits calculated from the characteristic peak of MPT is 0.27 ng/cm2 (S/N = 3). MPT on spinach, green pepper, and tomato surfaces were directly determined rapidly and the sensitivities were 1.42 ng/cm2, 0.84 ng/cm2, and 0.87 ng/cm2, respectively. The versatility and reliability of this approach underscore its potential for routine pesticide residue screening. Looking ahead, further optimization of this platform could extend its applicability to a broader spectrum of organophosphorus pesticides, bolstering food safety monitoring and reducing potential health risks.