Abstract: Surface plasmon resonance(SPR)immunosensor is a relatively new immunoassay technique and has been receiving more and more attention in recent years. However, a major disadvantage of SPR for bioanalytical applications is that low concentration or low molecular mass analytes could not be detected directly. Therefore, it is a challenging task to develop strategies for improving the detection limit/sensitivity of SPR. In this paper, authors present a novel strategy for improving the sensitivity of SPR immunosensing using streptavidin-biotinylated antibody complex. It is proven that the amplification strategy causes a dramatic improvement of the detection sensitivity. This amplification strategy is based on the construction of a molecular complex between streptavidin and biotin labeled protein. The complex can be formed in a crosslinking network of molecules so that the amplification of response signal will be realized due to the big molecular size of complex.

Key words: surface plasmon resonance technique, immunosensor, amplified assay, streptavidin-biotinylated antibody complex

摘要： 表面等离子体共振免疫传感器是一类相对新型的免疫检测技术。将链霉亲和素-生物素系统用于表面等离子体共振免疫传感的信号放大，实时检测了人免疫球蛋白G(hIgG)的蛋白浓度。发生免疫反应的传感片和生物素化抗体反应后，传感片表面的一层生物素分子随后与链霉亲和素-生物素化抗体复合物中的链霉亲和素的活性位点发生亲和反应，从而使传感片表面特异健合的物质质量显著增加，大大提高了免疫检测的灵敏度和检测限。免疫反应经放大后，可检测0.005～10μg/mL浓度区间内的hIgG。

关键词: 表面等离子体共振技术, 免疫传感器, 放大检测, 链霉亲和素-生物素化抗体复合物