基于微片激光器制备的微结构表面增强激光诱导击穿光谱的水溶液重金属检测  

Detection of Heavy Metals in Aqueous Solution via Surface-Enhanced Laser-Induced Breakdown Spectroscopy Using Microstructures Fabricated by Microchip Laser

作　　者：单焕明 王增辉 李润华 陈钰琦 Shan Huanming;Wang Zenghui;Li Runhua;Chen Yuqi(School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510641,Guangdong,China)

机构地区：[1]华南理工大学物理与光电学院,广东广州510641

出　　处：《中国激光》2025年第2期254-261,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(12174117,61875055)。

摘　　要：利用波形发生器对微片激光器进行脉冲调控,成功在黄铜衬底表面制备了微米量级的周期点阵微结构。基于不同周期微结构,研究了微结构表面增强激光诱导击穿光谱信号的增强机理并对水溶液中的重金属成分进行了高灵敏检测。实验研究了激光累积脉冲数所决定的表面周期微结构烧蚀坑洞深度对光谱信号增强效果的影响。结果表明,黄铜周期微结构衬底Cu I 515.20 nm谱线的信号强度较光滑衬底条件下最大可增强9.09倍;表面周期微结构能够显著增加等离子体温度和电子密度。在优化的表面周期微结构下开展了水溶液中重金属铬和铅的表面增强激光诱导击穿光谱(LIBS)的定量分析,Cr和Pb的检出限分别为106.3 ng/mL和49.2 ng/mL。在传统的表面增强LIBS基础上,通过制备和调控表面衬底的周期微结构,提高了水溶液中重金属元素的LIBS分析性能,为LIBS水溶液重金属成分检测提供了一种快速有效的高灵敏检测方法。Objective Owing to the development of modern industries,environmental water-pollution issues have become increasingly prominent.In industrial production,waste water containing heavy metals such as Pb and Cr is discharged into rivers and lakes,which threatens human health.Therefore,the development of highly sensitive detection technologies for harmful heavy metals in water is necessary.Laser-induced breakdown spectroscopy(LIBS)has been widely acknowledged for its advantages,such as the nonrequirement for sample pretreatment,full elemental-analysis capability,and non-contact operation.It has been widely applied in fields such as environmental monitoring,alloy analysis,coal and metallurgy,biomedical research,and space exploration.However,owing to the effects of liquid splashing and the quenching effect of water molecules on atomic radiation in plasma,LIBS presents a lower sensitivity and stability in the direct analysis of aqueous samples.The accuracy of LIBS in analyzing aqueous solutions can be improved by converting liquid-phase samples into solid-phase samples.Compared with the direct LIBS analysis of liquid-phase samples,surface-enhanced LIBS(SELIBS)requires only the deposition of a minute amount of sample on the surface of a solid substrate(such as aluminum,magnesium,or silicon)and solvent evaporation.The interaction between the laser pulse and metal substrate can effectively enhance the sample signal strength,thereby improving the detection sensitivity of the elements in the liquid sample.In this study,a small high-repetition-rate microchip laser was used to process the substrate surface to obtain the microstructures prior to SELIBS.Periodic dot-array microstructures were fabricated on brass-substrate surfaces.The effect of the periodic surface microstructure on the plasma temperature and electron density was investigated via SELIBS.The effect of the microstructure on the spectral intensities of Cr and Pb in aqueous solutions was investigated via LIBS analysis.Methods A microchip laser with a wavelength of 10

关 键 词：光谱学 激光诱导击穿光谱 微结构 微片激光器 信号增强 

分 类 号：O433.4[机械工程—光学工程]