一种快速检测Hg2＋的比率荧光传感器构建

以汞离子（Hg2＋）为检测对象，构建一种基于（silicon-doped carbon quantum dots，Si-CDs）-溶菌酶（lysozyme，Lys）功能化的金纳米簇的比率型荧光传感器。以发蓝色荧光的Si-CDs为参比荧光信号，发红色荧光的Lys功能化金纳米簇（Lys-AuNCs）为响应荧光信号构建比率荧光探针。基于Au＋-Hg2＋间的亲金效应，Hg2＋可高效猝灭Lys-AuNCs在670 nm波长处的荧光发射，而Si-CDs在470 nm波长处的荧光强度保持不变，其荧光强度比值（I670/I470）与Hg2＋（0～0.016 mg/L）呈良好的线性关系，线性方程为I670/I470=1.35－64.18C（Hg2＋）。对湖水、矿泉水、自来水3 个水样进行添加回收实验，其回收率均在94.3%～115.0%之间，检出限为0.001 mg/L（3σ），变异系数不大于10.3%，且并无其他金属离子干扰。

Development of a Ratiometric Fluorescence Sensor for the Rapid Detection of Hg2+

In this study, a ratiometric fluorescence sensor based on silicon-doped carbon quantum dots (Si-CDs) and lysozyme (Lys) functionalized gold nanoclusters (Lys-AuNCs) was developed for the rapid detection of mercury (II) ion (Hg2+). In the method, Si-CDs emitted a blue light as a reference fluorescence signal, and Lys-AuNCs emitted a red light as a response fluorescence signal. Hg2+could efficiently quench the fluorescence of Lys-AuNC at 670 nm (I670) by virtue of gold affinity between Au+ and Hg2+, while the fluorescence intensity of Si-CDs at 470 nm (I470) remains unchanged. The ratio of the fluorescence intensity at 670 nm and 470 nm (I670/I470) showed a good linear relationship with the concentration of Hg2+ in the range of 0–0.016 mg/L, which was fitted as follows: I670/I470 = 1.35–64.18C (Hg2+). The recoveries of Hg2+ spiked in lake water, mineral water and running tap water were in the range of 94.3%–115.0%. The detection limit of this sensor was 0.001 mg/L (3σ) with a variation coefficient not more than 10.3%. Other metal ions exhibited no interference for this sensor.