SERS Detection of Thiram in Biofluids Based on Ag Nanopocket/Cu Nanostructures

The extensive use of thiram has raised concerns regarding its adverse effects on human health. However, the current methods for detecting thiram in biofluids are complex, creating a critical need for a rapid approach. This study developed a surface-enhanced Raman spectroscopy (SERS) approach through synthesizing an ordered arrangement of silver nanopocket agglomerates on a copper foil surface via in situ reduction using chloride ions as a shape mediator. This Ag Nanopocket/Cu substrate exhibits a uniform distribution of gaps and cavities, creating high-density “hot spots” for the enhanced SERS effect. The Ag Nanopocket/Cu was used for sensing thiram in human urine and serum, achieving ultralow detection limits of 1.37 and 1.69 ppb, respectively. Linear correlations were established between the SERS intensity and logarithmic concentrations from 2 ppb to 2 ppm. This substrate displayed remarkable reproducibility in SERS signal collection from 225 randomly selected points, with a relative standard deviation of 8.18% and an enhancement factor of 3.6 × 106. Notably, this all-in-one approach eliminates complex pretreatment and completes “extraction and detection” within 10 min with satisfactory recoveries. The results show excellent agreement with those from high-performance liquid chromatography and offer great potential for cost-effective and rapid detection in thiram exposure applications.