It is of very significance to strictly and precisely detect trace inorganic arsenic ions (As³⁺), which may increase the risks of cancer in the skin, lungs, bladder, and diabetes diseases. Here, we report a simple and ultrasensitive method for dual-mode detection of arsenic by colorimetric and surface-enhanced Raman spectroscopy (SERS) based on glutathione functionalized gold nanoparticles (GSH/AuNPs). When As³⁺ ion are present in GSH/AuNPs solution, the binding of As³⁺ ion with GSH ligand induces the aggregation of AuNPs. The aggregation of GSH/AuNPs not only serves as indicator of As³⁺ ion for the perceptible color change from wine-red to blue, but also a highly efficient on-site SERS detection of As³⁺ ion due to the abundant hot spots. More importantly, the sensing system exhibits superior selectivity for As³⁺ ion detection compared with other common metal ions (Pb²⁺, Hg²⁺, Cu⁺, K⁺, Cr³⁺, Co²⁺ and Fe³⁺). Meanwhile, the limit of detection (LOD) of colorimetric and SERS are estimated to be 0.11 ppb and 0.14 ppb, respectively, which is lower than the WHO defined limit (10 ppb). Our study would provide a novel method for detection of As³⁺ion in drinking water and marine environmental monitoring, as well as offers a strategy for developing multi-mode sensing system for different applications.

严格和精确地检测痕量无机砷离子（As ³⁺）具有非常重要的意义，这可能会增加皮肤，肺部，膀胱和糖尿病疾病中癌症的风险。在这里，我们报告了一种基于谷胱甘肽功能化的金纳米粒子（GSH / AuNPs）的比色和表面增强拉曼光谱（SERS）用于砷的双模式检测的简单且超灵敏的方法。当作为³⁺离子存在于GSH /金纳米颗粒溶液中，作为结合³⁺与GSH配体诱导的AuNP的聚集离子。GSH / AuNPs的聚集不仅可作为As ³⁺离子指示从酒红到蓝色的明显颜色变化的指标，而且还可以高效现场SERS检测As ³⁺由于大量的热点离子。更重要的是，与其他常见金属离子（Pb 2 ⁺，Hg 2 ⁺，Cu ⁺，K ⁺，Cr ³⁺，Co ²⁺和Fe ³⁺）相比，该传感系统对As ³⁺离子的检测具有优越的选择性。同时，比色法和SERS的检出限（LOD）估计分别为0.11 ppb和0.14 ppb，低于WHO规定的限值（10 ppb）。我们的研究将为饮用水和海洋环境监测中的As ³⁺离子检测提供一种新方法，并为开发针对不同应用的多模式传感系统提供策略。