纳米金(AuNPs)与联吡啶钌(Ru(bpy)32+)通过静电作用形成AuNPs@Ru(bpy)32+纳米复合物.将该复合物组装在氧化石墨烯(GO)纳米片上,形成了可用于电化学发光检测的基底材料GO-AuNPs@Ru(bpy)32+.利用链霉亲和素(SA)分子可与4个生物素(biotin)分子相结合且二者的亲和力高的特点,再与识别元素相结合,实现了信号的放大.基于以上两点,利用适配体构建了无标记型适配体传感器,实现了癌胚抗原的灵敏检测.传感器的线性范围在1.0fg/L10.0pg/L之间,检出限为0.4fg/L.将该方法成功应用于人血清样品中癌胚抗原的测定,RSDs不大于8.3%,回收率在80.0%108.0%之间.
Graphene oxide(GO)-AuNPs@Ru(bpy)32+nanocomposite was prepared by electrostatic interaction of AuNPs and Ru(bpy)32+. GO-AuNPs@Ru(bpy)32+further reacted with GO to form GO-AuNPs@Ru(bpy)32+which was used as the substrate material for ECL detection.Streptavidin(SA)can strongly bind with 4biotin molecules to form SA-biotin.The enhanced electrochemiluminescence(ECL)signal was obtained by the combination of SA-biotin with the recognition element such as aptamer.An ECL aptasensor for sensitive detection of carcinoembryonic antigen(CEA) was fabricated based on GO-AuNPs@Ru(bpy)32+and SA-biotin.This aptasensor exhibits a linear relation in the range of 1.0fg/L to10.0pg/L with the detection limit of 0.40fg/L.The proposed method was successfully applied in determination of human serum samples with recoveries of 80.0% 108.0% and RSDs less than 8.3%.