壳聚糖包覆CdTe量子点传感器测定痕量汞

研究了在水相中合成了高质量的巯基乙酸包被的CdTe,通过1-(3-二甲氨基丙基)-3-乙基碳二亚胺(EDC)连接了壳聚糖。在pH6.4的PBS缓冲溶液中十六烷基三甲基溴化铵(CTMAB)存在下,汞离子对壳聚糖包覆的CdTe量子点具有荧光猝灭作用,实现了对水溶液中汞的定量检测。在最优条件下,壳聚糖包覆的量子点荧光猝灭与汞呈良好的线性关系,线性范围为0.3—15.0μg/L,检出限为9.5×10-8g/L。对5.0μg/L Hg2+平行测定11次,相对标准偏差为4.8%。该法用于水样品测定,相对标准偏差在5.0%以下,回收率为95.7%—102.6%,并且与ICP-AES相比,结果基本一致。该法用于实际样品测定误差较小,精密度与准确度均令人满意。

Determination of Trace Mercury by Chitosan-Capped CdTe QDs Sensor

The high-quality thioglycolic acid-capped CdTe quantum dots(QDs) were prepared in water phase,and chisotan was linked through 1-(3-dimethyl amino with propyl)-3-ethyl carbon two imine(EDC).It was found that the fluorescence quenching intensity of chisotan-capped CdTe QDs was caused by mercury ions in present of CTMAB in PBS buffer solution with pH of 6.4,that realized the quantitative detection of mercury in aqueous solution.Under the optimized conditions,the fluorescence quenching of chisotan-capped CdTe QDs was proportional to the concentration of mercury in the range of 0.3—15.0μg/L,and the detection limit was 9.5×10-8g/L.The RSD was 4.8% for detection of 5.0μg/L mercury for n=11 parallel determination.The method was applied to determination water samples with RSD less than 5.0%,and the recoveries were between 95.7% and 102.6%,and results were agreement compared with ICP-AES.The method is suit able to determine the real samples with less measurement error,and the precision and accuracy are satisfactory.