Hao Xiaojian, Sun Peng, Tian Yu, Pan Baowu
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan, Shanxi 030051, China.
ACS Omega. 2022 Jun 26;7(27):23605-23610. doi: 10.1021/acsomega.2c02199. eCollection 2022 Jul 12.
To overcome the shortcomings of low detection sensitivity and high spectral line background noise of traditional laser-induced breakdown spectroscopy (LIBS), a method of combining flat mirrors with gold nanoparticles (Au-NPs) was proposed. First, independent plane mirror and Au-NPs experiments were performed by using aluminum alloy samples. After that, the samples were placed under four conditions (None-LIBS; Three mirrors-LIBS; 20 nm Au-NPs-LIBS; 20 nm Au-NPs and Three mirrors-LIBS), and the differences between various spectral parameters were analyzed. The experimental results show that the optimal number of plane mirrors is 3, and the optimal size of gold nanoparticles is 20 nm. When 20 nm Au-NPs and Three mirrors are used in combination, the plasmonic spectral intensity can be effectively enhanced. The enhancement factor is up to 2.98 (Fe II 240.45 nm), and the signal-to-noise ratio (SNR) is significantly improved up to 10.03. The variation of the plasma temperature between 1 and 5 μs was also investigated, and the experimental results showed that the plasma temperature could be increased by the flat mirror, while the electron temperature was almost unchanged under the action of Au-NPs. It is shown that the combination of the two enhancement methods can effectively increase the spectral intensity and improve the signal-to-noise ratio, which will help to improve the detection performance of the LIBS system.
为克服传统激光诱导击穿光谱（LIBS）检测灵敏度低和谱线背景噪声高的缺点，提出了一种将平面镜与金纳米颗粒（Au-NPs）相结合的方法。首先，使用铝合金样品进行了独立的平面镜和金纳米颗粒实验。之后，将样品置于四种条件下（无LIBS；三面镜-LIBS；20 nm金纳米颗粒-LIBS；20 nm金纳米颗粒和三面镜-LIBS），并分析了各种光谱参数之间的差异。实验结果表明，平面镜的最佳数量为3，金纳米颗粒的最佳尺寸为20 nm。当同时使用20 nm金纳米颗粒和三面镜时，等离子体光谱强度可得到有效增强。增强因子高达2.98（Fe II 240.45 nm），信噪比（SNR）显著提高至10.03。还研究了1至5 μs内等离子体温度的变化，实验结果表明，平面镜可使等离子体温度升高，而在金纳米颗粒作用下电子温度几乎不变。结果表明，两种增强方法相结合可有效提高光谱强度并改善信噪比，这将有助于提高LIBS系统的检测性能。
