近红外荧光BSA-CdSeTe探针的制备及在生物学中的应用

Preparation and bio-application of near-infrared fluorescent probes of BSA-CdSeTe

本文用半胱氨酸作表面修饰剂,水相合成水溶性的近红外量子点CdSeTe,并偶联标记BSA,形成近红外BSA-CdSeTe探针。对CdSeTe QDs和BSA-CdSeTe探针进行荧光光谱分析,探讨了pH值、CdSeTe用量和反应时间这三个因素对近红外BSA-CdSeTe探针荧光强度的影响,对近红外BSA-CdSeTe探针进行了体外细胞成像实验和细胞毒性实验。结果表明,制得的CdSeTe粒径约5 nm,BSA-CdSeTe粒径约19 nm。当λex≈470 nm时,二者的λem均在750 nm左右。在pH=8、1m L CdSeTe和反应120 min时体系的荧光强度最大。当BSACdSeTe探针浓度在4~200μg·mL^(-1)范围之间,L929细胞的存活率均在85%之上。该探针在近红外荧光显微镜中可视,与L929细胞共孵育后可实现实时成像。因此,近红外荧光探针BSA-CdSeTe是一种可以进行实时细胞成像且生物相容性良好的纳米探针。

In this paper,the Near-hffrared（NIR）CdSeTe QDs had been synthesized in aqueous solution with cysteine as stabilizer. The BSA-CdSeTe probes were prepared by coupling CdSeTe QDs and BSA with EDC/NHS. CdSeTe QDs and BSA-CdSeTe probes were detected by fluorescence analysis（λex = 470 nm）. The effects of pH value, the amount of CdSeTe QDs and reaction time on fluorescence intensity- of BSA-CdSeTe were also studied. And the BSA-CdSeTe probes were analyzed by the cellular imaging and ey- totoxieity assay-. The results indicated that the size of CdSeTe QDs was about 5 nm and the size of BSA-CdSeTe was about 19 nm. And the hem of CdSeTe QDs and BSA-CdSeTe were about 750 nm. The fluorescence intensity of BSA-CdSeTe reached the maxi- mum value in the condition of pH = 8,1 mL CdSeTe QDs and the reaction time of 120 nfin. The value of L929 cell viability were a- bove 85% with the different concentration of BSA-CdSeTe（4 -200 μg · mL^-1 ）. After incubation with L929 cells, BSA-CdSeTe real- ized near-ilffrared real-time imaging. So BSA-CdSeTe was one nanoprobe of good bioeompatibilily and enabled real-time cell fluores- cence imaging.