HPTLC + SRES screening of pesticide for point-of-care application as shown with thiram in juice

Abstract

In this study, a HPTLC-platformed SERS detection was established for screening thiram in juice. After a simple extraction, the sample liquid was separated on HPTLC plates, which resulted in a specific zone for the analyte. Following infiltration with atomize water, the band of interest was easily scraped off and eluted. In parallel, a flexible and SERS-active substrate was fabricated by the in-situ synthesis of gold nanoparticles within cotton fabrics. Under optimized conditions, fingerprint-like signal at 1376 cm−1 of the analyte were easily recorded by a hand-held Raman spectrometer with enough LOD (0.5 mg/L), LOQ (0.9 mg/L) and reproducibility (<11.7%). The optimized screening system was further validated with pear, apple and mango juice by determining the spike-and-recovery rates (75.6 to 112.8%). It was demonstrated that this method could be a facile point-of-care testing system tailored for pesticide screening.