系统素量子点生物荧光探针的构建及特性

摘要

采用碳二亚胺法偶联系统素多克隆抗体和水溶性CdSe/ZnS量子点,制备了系统素量子点免疫荧光探针( antiSys-CdSe/ZnS),并对该探针的特异性和荧光特性进行了研究.结果表明,antiSys-CdSe/ZnS和系统素多克隆抗体的中点效价分别为1∶3.21×104和1∶9.45×104,两者对系统素的免疫识别能力近似;体系中硼酸缓冲液的pH为9.0时,antiSys-CdSe/ZnS量子点荧光探针溶液的荧光强度最强,其荧光强度约为原量子点荧光强度的47％;在牛血清白蛋白(BSA)存在时,antiSys-CdSe/ZnS 的荧光强度明显增加;当体系中含有1％ BSA时,antiSys-CdSe/ZnS溶液的稳定性和荧光强度最佳.%Conjugates of anti-Systerain antibody and carboxyl CdSe/ZnS (antiSys-CdSe/ZnS) can be synthesized via carbodiimide cross-linking procedure, and the corresponding fluorescence properties were investigated. Results show that the immunocompetence of antiSys-CdSe/ZnS is similar to that of anti-systemin antibody, and the titre of antiSys-CdSe/ZnS is 1:3. 21× 104 and 1:9. 45 × 104, respectively. The fluorescence intensity of antiSys-CdSe/ZnS is strongest at pH 9. 0 borate buffer, and its intensity is about 47% of the intensity of the corresponding CdSe/ZnS. In addition, the fluorescence intensity of antiSys-CdSe/ZnS increases with the addition of bovine serum albumin ( BSA). When the concentration of BSA in buffer is 1% , the prepared quantum-dot bioprobe is stable and the fluorescence intensity is the strongest.