Effects of Size and Concentration of Silver Nanoparticles on Enhancement Effect of Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy

One of the most appealing advantages of nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) lies in its enhancement effect of spectral intensity, which is influenced by the properties of the used nanoparticles. In the present work, the effect of size and concentration of silver nanoparticles (Ag NPs) on aluminum (Al) substrate were discussed. At a size of 68 nm and a concentration of 4.07 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup>mol/L for Ag NPs, the maximum spectral intensities of Al II 281.6 nm and Al I 396.2 nm emission lines was obtained, and their highest enhancement factors (EFs) were calculated to be 2.17 and 4.32, respectively. The electron temperature was calculated by Boltzmann plot and the electron number density was measured by Stark broadening, respectively. The results indicated that the electron temperature of NELIBS plasma was marginally higher compared to that of normal LIBS plasma, while the electron number density of NELIBS plasma was slightly lower than that of normal LIBS plasma.