AgNPs and MIL-101(Fe) self-assembled nanometer materials improved the SERS detection sensitivity and reproducibility

Recently, in the research of Surface-enhanced Raman scattering (SERS) technology, it is found that the preparation of enhanced substrate is particularly important. In this work, the most commonly used methods were used to synthesize AgNPs and MIL-101(Fe), and AgNPs/MIL-101(Fe) nanocomposite was obtained through self-assembly of the two substances. Four different probe molecules were detected with the self-assembled substrate and compared with the results of same probe molecules with AgNPs and MIL-101(Fe) as SERS substrate separately, it was found that AgNPs/ MIL-101 (Fe) nanocomposites had a strong enhancing effect as SERS substrate. The Enhancement Factor (EF) value of 10^-6 mol/L Rhodamine 6G (R6G) was calculated as 2.09 × 10⁹, and the Raman intensities of the peak relative standard deviation (RSD) of R6G Raman attribution was calculated as 7.55%. The time stability of the material was studied and it was found that the reduced Raman signal and poor reproducibility were due to the AgNPs placement time. AgNPs/ MIL-101 (Fe) nanocomposites were used as SERS substrate to detect Paraquat with a minimum concentration of 10^-12 mol/L. The signal values of Paraquat Raman detected at 10^-6 mol/L in different pH environments were relatively stable.