抗-转铁蛋白-纳米金探针的制备及对转铁蛋白免疫识别的光谱分析

Immobilization of Anti-Transferrin On Nano-Gold and Its Immune Recognition of Transferrin

利用碳二亚胺(EDC)将抗-转铁蛋白化学偶联到已修饰了半胱胺的纳米金表面,制备了抗-转铁蛋白-纳米金免疫探针,应用共振瑞利散射光谱,紫外-可见吸收光谱,透射电镜和激光散射等方法对其进行了表征。所制备的纳米探针具有良好的免疫活性。由于抗-转铁蛋白对转铁蛋白抗原具有特异性识别能力,借助免疫纳米探针在470nm处共振瑞利散射信号的放大作用,对转铁蛋白抗原进行特异性识别及免疫分析。转铁蛋白浓度在0.85～33.9×10-10mol.L-1范围内,470nm处共振瑞利散射相对强度与转铁蛋白浓度呈良好的线性关系,检测下限为8.5×10-11mol.L-1。

A novel strategy based on antigen-antibody interaction was developed by means of backfilling transferrin on antibody functionalized gold nanoparticles surfaces in the present study. Nano gold particles were immobilized with cysteamine layer by self-assembly, whose surfaces were chemically coupled with anti-transferrin antibodies by using El）C, forming the anti-transferrin-Au immuno-probes. The particles and the nano-probes were characterized by the integrated tools of resonance Rayleigh scattering （RRS）, UV-Vis absorption spectra, transmission electron microscopy （TEM） and laser light scattering. The result showed that the nano-probe with the ability of specific recognition of transferrin had good immune activity. The RRS peak at 470 nm was amplified obviously by using this signal amplification, and the antigen recognition was monitored via the enhancement of 470 nm RRS intensity when this binding event occurred. The result showed that the amplification strategy led to a dramatic im- provement of the detection sensitivity of transferrin, and the detection of transferrin featured a linear range of 0. 85 to 33. 9 × 10^-10 mol · L^-1 with the detection limit of 8. 5×10^-11 mol · L^-1.