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This work has focused on the development of a new analytical alternative based on the laser-induced breakdown spectroscopy (LIBS) technique for the fast, reliable, and economical determination of the gold and silver nanoparticle content in a low linear concentration range between 2.9 and 0.058 μg mL−1 and 2.9–0.116 μg mL−1, respectively, without requiring complicated sample pretreatment procedures or advanced separation techniques. Metallic nanoparticles are currently essential materials for the development of new technologies in different scientific and technical areas. However, numerous studies have pointed out these nanomaterials' toxic and polluting potential and the various health implications for humans, animals, and the ecosystem. The current reality reflects the lack of analytical techniques with low economic, environmental, and health impacts and the capacity to quantify the total metallic nanoparticle content. For this purpose, a novel and simple method for the selective capture of gold and silver nanoparticles, consisting of a chemically functionalized glass surface, has been custom-developed for subsequent analysis with LIBS. The results show that the proposed method, employing a functionalized sample glass support, presents a suitable analytical performance characterized by increased sensitivity, specifically 4.7% and 329.2% for Au-NPs and Ag-NPs, and proportionally decreased error in the slope and intercept of the calibration curves, 68% for Au-NPs and 87% for Ag-NPs, respectively. [ABSTRACT FROM AUTHOR]

The ability of laser-induced breakdown spectroscopy (LIBS) to detect Cd in rice is limited. A nanoparticle enhancement method combined with film preparation to improve the detection with LIBS is proposed. The film sample was prepared by scraping the mixed rice powder and silver nanoparticle (Ag NP) suspensions onto a glass slide, which was then dried in air. Finally, the glass slide that contained the analytes and Ag NPs was used for LIBS determination. Compared with the traditional tableting method, the spectral intensity of Cd is increased by a factor of 20. Thus, the limit of detection was 0.17 μg g−1, and the limit of quantification was 0.56 μg g−1. The results demonstrate that the method of nanoparticle-enhanced LIBS (NELIBS) combined with film preparation can be used to distinguish rice with excessive Cd content. [ABSTRACT FROM AUTHOR]

The effect of the shape of the nanoparticles on the nanoparticle-enhanced LIBS (NELIBS) signal should be clarified. The present study reports on the effect of the silver (silver chloride) nanoparticle shape (nanospheres, nanocubes, and nanowires) on the LIBS signal for different target materials; two metals (aluminum and zinc) and one semiconductor (silicon). The shape enhancement factor and the plasma parameters, namely plasma temperature and electron density, have also been evaluated. Silver nanoparticles have been characterized using different techniques, including SEM, UV-vis, and XRD. The results showed that the clusters formed in the silver nanowires and nanocubes play an essential role in the laser pulse's absorption mechanism and, consequently, enhance the LIBS signal. Nanowires followed by nanocubes showed better enhancement than nanospheres, confirmed by the shape-dependent enhancement factor. However, the laser-induced plasma parameters (plasma temperature and electron density) have not been affected much by the nano-shape change. [ABSTRACT FROM AUTHOR]