High sensitivity analysis of soil by laser-induced breakdown spectroscopy with Ag nanoparticles

• Nanoparticles were synthesized by pulsed laser irradiation in liquids. • Nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) was used to analyze soil samples. • Compared with conventional LIBS, the limits of detection of NELIBS reached a sub-ppm level. Various studies have been conducted to improve the detection sensitivity of metallic elements in soil using laser-induced breakdown spectroscopy (LIBS) by controlling environmental parameters or assisting with other methods, which inevitably increases the cost and complexity of LIBS. In this study, a simple LIBS assisted with self-synthetic Ag nanoparticles enhancement method was proposed to achieve sensitive analysis of the metallic elements in soil samples. The calibration curves of Fe, Mn, Cu, and Zn using LIBS and nanoparticle-enhanced LIBS were established. The limits of detection of Fe, Mn, Cu, and Zn in the soil were 28.4 ppm, 6.3 ppm, 0.34 ppm, and 2.4 ppm, respectively, and the relative errors were all below 4%, which were better than those of conventional LIBS. These results show that Ag nanoparticles can promote further development of LIBS elemental analysis in soil.