Rapid detection and efficient removal of heavy metal ions from environmental water are of considerable importance to tackle the water pollution problem. In this work, a simple but efficient strategy named metal-chelate induced nanoparticle aggregation enhanced laser-induced breakdown spectroscopy (MINAELIBS) was proposed for signal enhancement aiming at ultra-sensitive detection of trace levels of metal elements in liquid samples. Unlike the surface contact approach previously reported in the literature, direct mixing of gold nanoparticles (AuNPs) and metal chelates increased the contact area, adhesion force, and uniformity between analytes and AuNPs. As a result, under the optimal conditions, the limits of detection (LODs) of Cd, Cu, Ag, Pb, and Cr were 4.6, 1.5, 3.4, 3.5, and 3.5 ng mL⁻¹, respectively. The LODs of target elements were notably 7–10 times lower than those of chelating reagent enrichment alone and 3–4 orders of magnitude lower compared to traditional LIBS methods, which demonstrates the feasibility of MINAELIBS in analysis of liquid samples at the ppb level. Application of AuNPs for high-performance signal enhancement has undoubtedly pushed the method sensitivity of traditional LIBS analyses to a new level. In addition, the recoveries of all the analytical elements in the environmental water samples were in the range from 88.6% to 109.9%, which further proves the feasibility and potential of MINAELIBS in practical liquid sample analysis.

中文翻译：

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金属螯合物诱导的纳米粒子聚集增强的激光诱导击穿光谱，用于超灵敏地检测液体样品中的痕量金属离子

快速检测和有效去除环境水中的重金属离子对于解决水污染问题非常重要。在这项工作中，针对金属样品中痕量金属元素的超灵敏检测，提出了一种简单但有效的策略，称为金属螯合物诱导的纳米粒子聚集增强的激光诱导击穿光谱法（MINAELIBS），用于信号增强。与以前文献中报道的表面接触方法不同，金纳米颗粒（AuNPs）和金属螯合物的直接混合增加了接触面积，粘附力以及分析物和AuNP之间的均匀性。结果，在最佳条件下，Cd，Cu，Ag，Pb和Cr的检出限（LOD）为4.6、1.5、3.4、3.5和3.5 ng mL ^-1， 分别。与传统的LIBS方法相比，目标元素的LOD明显比单独螯合剂富集的LOD低7–10倍，并且低3–4个数量级，这表明MINAELIBS在ppb级液体样品分析中的可行性。AuNPs在高性能信号增强中的应用无疑将传统LIBS分析的方法灵敏度提高到了一个新水平。此外，环境水样中所有分析元素的回收率在88.6％至109.9％的范围内，这进一步证明了MINAELIBS在实际液体样品分析中的可行性和潜力。