Lab-on-paper surface-enhanced Raman spectroscopy platform based on self-assembled Au@Ag nanocube monolayer for on-site detection of thiram in soil

A paper-based surface-enhanced Raman spectroscopy (SERS) substrate was prepared by assembling Au@Ag nanocubes onto a patterned paper with the assistance of a mask paper by liquid-liquid interface self-assembly techniques. The paper-based SERS substrate was glued to the glass slide to construct a novel lab-on-paper SERS platform. This paper-based SERS sensor possesses a sample injecting zone together with a SERS detection zone in order that sample pretreatment and detection could be performed simultaneously. The SERS performance of this paper-based sensor was investigated by using 4-MBA as a probe molecule, and its enhancement factor as high as 0.56 x 10(5) could be obtained. Additionally, the SERS sensor demonstrated an excellent repeatability with the relative standard deviation for the variation from the spot-to-spot Raman intensity as low as 12.8%. Based on the superiority and functionality of this paper-based SERS platform, sensitive SERS quantitative analysis of thiram in soil could be achieved, which suggests its significant application prospects for the measurement of pesticides in soil without any pretreatment.