Analysis of Cs solution by nano-silica particles-enhanced laser-induced breakdown spectroscopy

Abstract

Nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) represents a promising tool for detecting trace elements. This work improves NELIBS by substituting metal nanoparticles with nano-silica particles to achieve rapid detection of Cs elements at low concentrations. This substitution effectively prevents cluster formation and simplifies the experiment preparation process. The research optimizes factors such as target movement speed, nanoparticle concentration, and nanoparticle size to identify the optimal experimental parameters. Comparative analysis of the 3D morphology of laser ablation areas with and without nanoparticles reveals that evenly distributed nano-silica particles on the target surface provide the most effective colloidal particle lens array (CPLA) effect, and increasing the roughness of the target surface thereby enhancing the quality of laser ablation. With a laser frequency of 10 Hz, optimal characteristic spectral signals are achieved when the target movement speed exceeds 2 mm/s. Under conditions of a concentration of 0.1 mg/mL and an average particle size of 50 nm, the greatest enhancement effect on Cs element LIBS characteristic spectral signals is observed. Consequently, the limit of detection (LOD) and the limit of quantitation (LOQ) of elemental Cs by LIBS technology are reduced to 0.45 mg/L and 1.51 mg/L, respectively, facilitating real-time detection of Cs element at low concentrations. In addition, the nano-silica particles have also had a certain enhancement effect on the spectral signal of elemental properties in the target, proving that enhancing the LIBS characteristic spectral signal using nano-silica particles is a feasible method.