表面等离子体激元共振方法检测三聚氰胺的含量

Surface Plasmon Resonance for Melamine Detection

基于三聚氰胺与DNA的反应,建立了一种利用表面等离子体激元共振技术检测三聚氰胺的方法。固定在芯片表面的NH2-A15捕获T15-biotin和链霉亲和素的混合溶液。当有三聚氰胺存在时,由于三聚氰胺可以与胸腺嘧啶(T)结合导致连接到芯片表面的T15-biotin和链霉亲和素减少,SPR信号与没有加入三聚氰胺时的信号值相比有所下降。因此,SPR信号的变化可反应三聚氰胺的浓度。该方法对三聚氰胺的最低检测浓度为0.32 n M,为检测牛奶中三聚氰胺的含量提供了可能。

Surface plasmon resonance （SPR） assay of melamine was carried out based on the competitive reaction of melamine and DNA. The oligonucleotide probe （NH2-A15 ） was first immobilized onto the carboxymethylated dextrancovered SPR chips, followed by the injection of the mixed solution of T15 -biotin and streptavidin （SA）. Due to the interaction between melamine and thymine, the amount of the SA-biotin-T15 complex linked to the chip surface was decreased when adding melamine. By examining the SPR responses caused by the attached SA-biotin-T15 complex, the concentrations of melamine could be determined. The detection limit of this method was 0. 32 nM, which held great promise for melamine assay in milk samples.