Flexible paper-based substrate for SERS detection of methyl parathion

• 1、School of Food Science and Technology, Jiangnan University, Wuxi 214122, China

Abstract：In this paper, a flexible paper-based substrate assembled with filter paper and gold nanoparticles (Au NPs) was fabricated to detect methyl parathion in actual samples based on surface-enhanced Raman spectroscopy (SERS). The paper-based substrate was made by immersing the filter paper into Au NPs. Portable Raman spectrometer and 4-mercaptobenzoic acid (4-MBA) were used to optimize the SERS signal and characterize the property of the substrate, including reproducibility, stability and sensitivity. Under optimal detection condition, the Raman intensity and the concentration of methyl parathion standard solution have a good linear relationship (y=3.457×1011x+171.126, R2=0.9989）in the range of 0.018-0.354 μg/cm2 and the detection limit as low as 0.011 μg/cm2. The uniform distribution of gold nanoparticles on the surface of the paper can increase the "hot spot" effect and improve the reproducibility and sensitivity of the detection method. The paper-based substrate is easy to bend to contact the surface of the sample completely, which can collect target molecules effectively. This method is simple, rapid, can be used for the detection of actual samples.

Keywords： food pesticide detection gold nanoparticles the paper-based substrate methyl parathion SERS