基于AgNCs-Ce:ZONPs发光复合纳米材料的电致化学发光免疫传感器对肿瘤标志物灵敏检测的研究

Electrochemiluminescence immunoassay for sensitive detection of cancer markers based on AgNCs-Ce:ZONPs luminescent nanocomposites

该研究以含有铈的氧化锌复合纳米材料(Ce:ZONPs)为固载基质,以BSA作为模板和还原剂在Ce:ZONPs表面原位合成银纳米簇(Ag NCs)制得发光复合纳米材料(Ag NCs-Ce:ZONPs),并以此作为信号探针构建了电致化学发光(Electrochemiluminescence,ECL)免疫传感器用于癌胚抗原(CEA)的灵敏检测。在该工作中,BSA作为天然蛋白质,表面含有大量的氨基和巯基,介于共价键Ag-N和Ag-S,BSA可以作为优良的纳米簇配体。同时通过BSA的成膜性,制备BSA功能化的Ce:ZONPs,从而在Ce:ZONPs@BSA的表面生成大量、粒径小于2 nm的Ag NCs,获得高效、稳定的电致化学发光。最后利用该复合物上BSA剩余的氨基与anti-CEA(Ab2)中的羧基交联,从而制备出Ag NCs-Ce:ZONPs/Ab2探针。电极敏感界面的构建是在裸玻碳电极上修饰一层功能化BSA的TiO_2纳米复合物(TiO_2@BSA),提供充足的活性位点来固载anti-CEA(Ab1),从而制得了ECL免疫传感器。基于夹心型反应模式,此免疫传感器实现了对CEA的灵敏检测,线性范围2.5ng/m L至80 ng/m L。

In this work, the electrochemiluminescent nanocomposite was proposed through Ag NCs in situ generating on the surface of bovine serum albumin（BSA） functionalized zinc oxide containing cerium. Notably, BSA as stabilizing agent provided abundant binding sites to potentially bind and further reduce Ag ions for generating Ag NCs.The Ag NCs-TiO_2 NFs composites achieved highly efficient ECL, biocompatibility, ease of labeling and easy film-forming. In view of these advantages, the composites could have great potential as a signal probe to construct electrochemiluminescence（ECL） immunesensor for detection of carcinoembryonic antigen（CEA）. Meanwhile, the nanocomposites（TiO_2@BSA） were modified onto the surface of a glassy carbon electrode（GCE）, which afforded a large surface area for anchoring massive Ab1 via CO-NH bonding. Based on the ＂sandwich reaction＂ strategy, this immunesensor provided an ultrasensitive ECL detection of CEA with a linear response from 2.5 ng/m L to 80 ng/m L.