以CdCl2·2.5H2O,Na2SeO3和NaBH4为反应物,制备巯基丁二酸稳定的CdSe量子点.在合成的量子点中加入一定浓度的铜离子,铜离子结合于量子点表面而使其荧光猝灭.在猝灭后的体系中加入青霉胺,由于青霉胺能使结合于量子点表面的铜离子释放出来而使量子点的荧光恢复.据此,建立了一种CdSe量子点“开关”测定青霉胺的新方法.在选定的实验条件下,方法的线性范围为1~72 μg/mL,检出限为0.031 μg/mL.应用于实际样品中青霉胺的测定,结果令人满意.

CdSe quantum dots were prepared by the reaction of CdCl2·2.5H2O,Na2SeO3 and NaBH4 in water and in the presence of mercaptosuccinic acid as stabilizer.The fluorescence of quantum dots can be significantly quenched by copper ions.However,in the presence of penicillamine,copper ions were released from the quantum dots and thus restored the fluorescence of quantum dots.A new type of fluorescence turn-on assay for detection of penicillamine using quantum dots/copper ion ensemble is developed.Under the selected conditions,the response was linearly proportional to the concentration of penicillamine from 1 to 72 μg/mL,the limit of detection was 0.031 μg/mL.The developed method has been successfully applied to the detection of penicillamine in real samples with satisfactory results.