基于柠檬酸盐修饰CdS量子点的高灵敏Ag^+传感器

Highly Sensitive Ag^+ Sensor Based on Citrate Capped CdS Quantum Dots

以柠檬酸三钠作为表面修饰剂,利用简单的方法合成了水溶性柠檬酸三钠修饰的CdS量子点(Cit-CdS)。研究了反应前驱体中nCd/nS比、反应溶液pH值、反应温度等条件对产物的荧光性质的影响。在巯基乙酸存在下,Ag+能大大增强量子点的荧光。基于此,构建了基于Cit-CdS的高灵敏Ag+传感器。传感器在Ag+浓度为5.0×10-9~2.0×10-6mol·L-1内对银离子线性响应良好,检测限为1.0×10-9mol·L-1。其它常见金属离子对Ag+的测定并无明显干扰。

Water-soluble citrate sodium capped CdS quantum dots （Cit-CdS） were prepared using a simple method. The effects of synthetic conditions such as the molar ratio of Cd/S, pH value of reaction solution, reaction temperature were investigated on the photoluminescence properties of CdS. In the presence of thioglycolic acid, the photoluminescence intensity of CdS was greatly enhanced by Ag ^＋ . Based on this phenomenon, a highly sensitive Ag＋ sensor was developed. The sensor showed a linear response to Ag＋ in the concentration ranging from 5.0×10^-9 mol·L^-1 to 2.0×10^-6 mol·L^-1, with a detection limit of 1.0×10^-9 mol·L^-1.