改性表面增强拉曼基底对几种重金属的定量检测

Quantitative detection of several heavy metals by modified surface enhanced Raman substrate

摘要:

重金属离子对水质及其应用有着严重的影响，开发高选择性及灵敏度的重金属离子检测平台在水资源保护中有着重要的意义. 采用4-巯基苯甲酸功能化金纳米粒子为载体制备的表面增强拉曼(SERS)溶胶基底，对水溶液中Pb2+、Cd2+、As3+等重金属离子具有较强的选择性和较高的灵敏度. 实验发现，SERS基底对Pb2+、Cd2+和As3+的拉曼检测光谱在1047、1075、1587 cm-1附近有着明显的振动频带位移及峰强变化. 通过对溶胶基底优化得到了性能优异的增强基底，能够实现对3种重金属离子的区分，对重金属的检出限可达0.1 mg/L，并在0.5~100 mg/L范围呈线性关系，并成功的对真实水样中Pb2+进行了加标验证实验. 该基底提供了一个快速、便捷的重金属鉴别检测方法，且具有较好的增强效果和重金属定量分析能力，为水中重金属离子的高效检测提供了有效手段.

Abstract:

Heavy metal ions have a serious impact on water quality and its application, and the development of a highly selective and sensitive detection platform for heavy metal ions has great significance in the water resources protection. The surface-enhanced Raman (SERS) sol substrate was prepared by using 4-MBA to modified gold nanoparticles as a carrier, which has strong selectivity and high sensitivity to heavy metal ions such as Pb2+, Cd2+, and As3+ in aqueous solution. The experiments found that the Raman detection spectra of Pb2+, Cd2+ and As3+ by the SERS substrate have obvious shifts in vibration frequency bands and peak intensities near 1046cm-1, 1075cm-1, and 1587cm-1. An optimized enhanced substrate was obtained by optimizing the sol-substrate, which can distinguish three kinds of heavy metal ions. The detection limit for heavy metal ions can reach 0.1mg/L, and it has a linear relationship in the range of 0.5 to 100 mg/L. A standard addition verification experiment was performed on Pb2+ in real water samples. This substrate provides a fast and convenient method for heavy metal identification and detection with better enhancement effect and heavy metal quantitative analysis ability, and provides an effective means for the efficient detection of heavy metal ions in water.