银-石墨烯纳米复合物标记电化学适配体传感器用于血清中凝血酶的检测

In this paper, a new electrochemical aptasensor was designed for determination of thrombin using silver-decorated graphene nanosheets as labels on aptamer/nanogold-modifed glassy carbon electrode. Growth of silver nanocrystals on graphene was prepared based on one-step method by using formaldehyde as reducing agent and poly(N-vinyl-2-pyrrolidone) as the surface modifier under mild conditions. The as-prepared silver-graphene nanocomposites were empolyed for the labelling of aminated aptamers. The assy was carried out in PBS, pH 7.4 with a sandwich-type assay mode by using the decorated nanosilver as indicators. Under optimal conditions, the electrochemical aptasensors exhibited a wide linear range from 0.01 pM to 1.0 nM thrombin with a low detection limit (LOD) of 3.33 fM. The precision, selectivity and stability of the aptasensors were acceptable. Importantly, the methodology was monitored with thrombin spiked sample in blank fetal calf serum, and the recovery was 91 - 123%.