National Tsing Hua University, Department of Materials Science and Engineering, Hsinchu, Taiwan.
Biosens Bioelectron. 2012 Apr 15;34(1):286-90. doi: 10.1016/j.bios.2011.11.035. Epub 2011 Nov 28.
In this study, a CdSe/ZnS quantum dot (QD)-based immunosensor using a simple optical system for human serum albumin (HSA) detection is developed. Monoclonal anti-HSA (AHSA) immobilized on 3-aminopropyltriethoxysilane (APTES)-modified glass was used to capture HSA specifically. Bovine serum albumin (BSA) was used to block non-specific sites. The solution, containing AHSA-QD complex prepared by mixing biotinylated polyclonal anti-HSA and streptavidin coated QD, was used to conjugate with the HSA molecules captured on AHSA/BSA/APTES-modified glass for the modification of HSA with QD. A simple optical system, comprising a diode laser (405 nm), an optical lens, a 515-nm-long pass filter, and an Si-photodiode, was used to detect fluorescence and convert it to photocurrent. The current intensity was determined by the amount of QD specifically conjugated with HSA, and was therefore HSA-concentration-dependent and could be used to quantify HSA concentration. The detection limit of the pure QD solution was ~3.5×10(-12) M, and the detection limit for the CdSe/ZnS QD-based immunosensor developed in this study was approximately 3.2×10(-5) mg/ml. This small optical biosensing system shows considerable potential for future applications of on-chip liver-function detection.
本研究开发了一种基于 CdSe/ZnS 量子点（QD）的免疫传感器，该传感器使用简单的光学系统用于人血清白蛋白（HSA）的检测。单克隆抗 HSA（AHSA）固定在 3-氨丙基三乙氧基硅烷（APTES）修饰的玻璃上，用于特异性捕获 HSA。牛血清白蛋白（BSA）用于封闭非特异性结合位点。将生物素化的多克隆抗 HSA 和链霉亲和素包被的 QD 混合制备的 AHSA-QD 复合物溶液用于与 AHSA/BSA/APTES 修饰的玻璃上捕获的 HSA 分子结合，以用 QD 修饰 HSA。使用包含 405nm 激光二极管、光学透镜、515nm 长通滤波器和 Si 光电二极管的简单光学系统来检测荧光并将其转换为光电流。光电流的强度由与 HSA 特异性结合的 QD 的量决定，因此与 HSA 浓度有关，可用于定量 HSA 浓度。纯 QD 溶液的检测限约为 3.5×10(-12) M，本研究中开发的基于 CdSe/ZnS QD 的免疫传感器的检测限约为 3.2×10(-5) mg/ml。这种小型光学生物传感系统在未来的片上肝功能检测应用中具有很大的潜力。
