纳米金免疫凝集比率光度法检测IgG

Ratiometric Spectrophotometric Determination of IgG Based on Immunoaggregation of Au Nanoparticles

利用柠檬酸钠还原法制备了13nm胶体金,透射电子显微镜表征其具有良好的单分散性,通过它与牛血清蛋白(BSA)作用的紫外-可见光谱表明其对蛋白具有良好的生物亲和性。以羊抗人免疫球蛋白G(IgG)修饰的金纳米粒子作探针,基于金纳米粒子免疫聚集导致其消光系数和分散度的变化建立了人IgG的比率光度分析方法。结果表明所制备的纳米金标记探针在人IgG浓度100ng/mL～100μg/mL范围内有良好的线性响应,加标法测定结果表明该法具有良好的回收率和精密度。以细胞色素C(CytoC)和辣根过氧化物酶(HRP)两种蛋白质作对照实验,发现所制备的金纳米探针对IgG具有高度的特异性。

Gold nanoparticles （AuNPs） were prepared through the reduction of HAuCl4 with citrate. TEM analysis showed that the as-synthesized AuNPs were well monodispersed 13 nm spherical particles. The bioaffinity of the AuNPs was proved by studying their interaction with BSA using UV-Vis spectra. Based on the aggregation of gold nanoparticles that were coated with goat-anti-human IgG in the presence of human IgG,which resulted in an absorption change of the UV-Vis spectra,a ratiometric spectrophotometric method for the determination of human IgG was proposed. The specificity of the method towards IgG was confirmed using proteins Cyto C and HRP as controls.