Highly catalysis amplification of MOF Nd -loaded nanogold combined with specific aptamer SERS/RRS assay of trace glyphosate.

A neodymium metal-organic framework (MOF Nd ) was prepared using 1 H -pyrazole-3,5-dicarboxylic acid (H 3 pdc) and 2-pyrazinecarboxylic acid as ligands. Through the addition of HAuCl 4 as a precursor and NaBH 4 as a reducing agent, a new MOF Nd -loaded nanogold (AuNPs) (Au@MOF Nd ) nanosol with good stability and high catalytic activity was conveniently prepared via a solvothermal-reduction method and characterized. It was found that the indicator reaction of reducing HAuCl 4 by Na 2 SO 3 to generate AuNPs was slow. Au@MOF Nd strongly catalyzes this nanoreaction, and the produced AuNPs exhibit a strong resonance Rayleigh scattering (RRS) peak at 370 nm, and a strong surface-enhanced Raman scattering (SERS) peak at 1617 cm -1 with the addition of the molecular probe Victoria blue 4R (VB4r). A novel SERS/RRS di-mode quantitative analysis method for glyphosate (GLY) was established by coupling this new Au@MOF Nd catalytic indicator reaction with the aptamer (Apt) reaction of GLY, with SERS and RRS detection limits of 0.02 nM and 0.3 nM, respectively. It has been applied to the analysis of soil samples with a recovery rate of 93.0%-106.5% and precision of 2.2%-4.1%, and the results were satisfactory.