应用水相合成的CdTePCdS核壳型量子点荧光探针测定DNA

Application of CdTePCdS Core-Shell quantum dots synthesized in an aqueous solution as fluorescence probe in the determination of nucleic acids

以巯基丙酸（HS-CH2CH2COOH）为稳定剂水相合成了核壳型CdTePCdS量子点（QDs）。CdTePCdSQDs具有宽而连续的激发光谱和狭窄对称的发射光谱，最大发射波长位于578nm。与DNA作用后荧光强度显著降低。基于DNA对量子点荧光的猝灭效应，将CdTePCdS量子点作为荧光探针建立了一种简便快速测定DNA的荧光分析法，详细研究了pH、量子点浓度、离子强度、温度等备件对量子点荧光及DNA测定的影响。该方法测定ctDNA线性范围为50．0—750．0ng／mL，检出限为20ng／mL．7次重复测定O．5ttg／mLctDNA的相对标准偏差为2．0％。方法可用于合成样品的测定。

Nanometcr-sized fluorescent particles were synthesized in an aqueous solution. The CdTePCdS Core-Shell quantum dots have a narrow, symmetric emission spectrum and a broad, continuous excitation spectrum. A fluorescence method was developed for the rapid determination of DNA with functionalized CdTePCdS QDs as a fluorescence probe, based on the fluorescence quenching of the QDs in the presence of DNA. The maximum excitation and emission wavelengths of CdTePCdS QDs were at 360 and 578 nm, respectively. Under optimum conditions, the calibration curve is linear over the range 50 .0 - 750.0 ng/mL, with a detection limit of 20 ng/mL. The relative standard deviation of seven replicate measurements for 500.0 ng/mL ctDNA is 2.0%. The recovery and RSD are satisfactory. This method is simple, rapid and sensitive and shows promise in the application of biologic systems.