A balsam pear-shaped CuO SERS substrate with highly chemical enhancement for pesticide residue detection.

Abstract

Simple and traditional hydrothermal fabrication of a novel balsam pear-shaped CuO with high SERS enhancementis presented. XRD (X-ray diffraction), SEM (scanning electronic microscopy), TEM (transmission electron microscope), HRTEM (high-resolution transmission electron microscope), UV-Vis, and Raman are adopted to ensure that this balsam pear-shaped CuO with dense nanoparticle protuberance is successfully prepared. The LOD of this CuO SERS substrate is 4.79μgL-1 with R6G as molecular probe. By using DFT (density functional theory) calculation and FDTD (finite difference time domainmethod) simulation, both EM (electromagnetic enhancement) and CM (chemical enhancement) mechanisms are investigated, and the results show that these two-enhancement mechanisms can coexist in this balsam pear-shaped CuO. Finally, the prepared substrate has been applied for the determination oftrace levels of paraquat in solution, and results show that its LOD for paraquat is275μgL-1 (optimum Raman band: 1646cm-1 Raman shift), which is better than the government standard in China. Adexterous and facile way for fabrication of CuO SERS-active substrates with low cost and high performance, quite promising in detection of chemically hazardous substances and pesticide residueis provided. Graphical abstract.