CdTe量子点功能化玻片的制备及其对Pb2+浓度的检测

通过羟基化和氨基硅烷化处理,得到表面接枝氨基的玻片载体。水相合成巯基乙酸修饰的CdTe量子点(CdTe-TGA),采用EDC/NHS活化反应,将量子点偶联到氨基化玻片表面,制备出具有荧光性能的功能化玻片。考察了量子点与EDC的量比、活化时间、偶联温度以及偶联时间对偶联效果的影响。结果表明,在量子点与EDC的量比为1:30、活化时间1 h、偶联温度30 ℃、偶联时间4 h条件下获得的功能化玻片具有最佳的荧光性能。将该条件下制备的功能化玻片用于水溶液中Pb²⁺的浓度检测,得到玻片相对荧光猝灭强度随Pb²⁺浓度变化的线性曲线,线性范围为1.0×10^-9~4.0×10^-8mol·L^-1,检出限为3.8×10^-9mol·L^-1,且具有良好的选择性。该方法可以灵敏而准确地检测Pb²⁺浓度。

Preparation of CdTe Quantum Dots Modified Wafer and Its Application in Pb2+Detection

A new method using wafer modified by CdTe quantum dots to detect the concentration of Pb²⁺ was discussed in this paper. The surface of glass wafer was modified by means of hydroxylation and aminosilanization to obtain amino-modified slide. The thioglycolic acid-capped CdTe quantum dots synthesized in aqueous phase were successfully coupled on the surface of amino-modified slide by using EDC/NHS activation reaction. Some influence factors were discussed, such as molar ratio of QDs/DEC, activation time, coupling temperature and coupling time. The results show that the functional wafer with QDs/DEC molar ratio of 1:30, activating time of 1 h, reacting time of 4 h, and reacting temperature of 40 ℃ has the best fluorescence performance. The obtained wafers were successfully used to measure the concentration of Pb²⁺ in aqueous solution. The quenched fluorescence intensity of functional wafer is linearly proportional to the concentration of Pb²⁺ between 1.0×10^-9 and 4.0×10^-8 mol·L^-1 with a detection limit of 3.8×10^-9 mol·L^-1. Good selectivity is also proved by interfering ion experiment. This proposed method can be used to detect Pb²⁺ sensitively and accurately.