基于抗体包被纳米金和铜配合物共固定修饰电极的癌胚抗原安培免疫传感器研究

研制了基于抗体包被化学镀纳米金(AuNPs)和Cu(bpy)2(ONO)]NO3配合物(CuL)共固定修饰玻碳电极(GCE)的安培免疫传感器,并用于血清中癌胚抗原(CEA)的检测。首先将GCE电极表面氧化形成羧基,进而键合上乙二胺。将此胺化电极浸泡在CuL和化学镀金溶液后,CuL可通过π-π堆积作用吸附到GCE表面,并在电极表面还原成30~50nm的纳米金层(GCE|CuL/AuNPs)。将上述电极浸泡在CEA抗体(anti CEA)溶液中,利用AuNPs固定anti CEA,并通过辣根过氧化物酶(HRP)封闭剩余的AuNPs位点,由此构建了一类快速检测CEA的无试剂安培免疫传感器(GCE|CuL-AuNPs/anti CEA-HRP)。其中CuL作为电子媒介体对过氧化脲(CP)有催化还原作用,而且HRP可增强这种作用。当该传感器在37℃下,含CEA的pH6.5PBS溶液中温育30min后,随着温育液中CEA浓度的增加,电极表面形成的免疫复合物也增加,导致CuL对CP的催化电流下降。电流下降百分比1%与CEA浓度在0.1~80ng/mL之间成线性关系,检测限为0.052ng/mL(3σ)。由于采用化学镀法可...

One Amperometric Immunosensors for Carcinoembryonic Antigen in Human Serum Based on Antibody Coated with Electroless Plating Nano Gold and Copper Complex Coimmobilized Electrode

A novel amperometric immunosensor for carcinoembryonic antigen(CEA)in human serum was estab-lished based onCu(bpy)_2(ONO)]NO_3(CuL)and CEA antibody coated with gold nanoparticles(AuNPs)com-posite film.The glassy carbon electrode(GCE) was firstly oxided and carboxyel group was formed on its surface,and then ethylene diamine was bonded to it.The ammoniated electrode was soaked in CuL and electroless gold plat-ing solution.Then CuL can be absorbed on GCE surface by π-π stacking interaction and AuNPs film of 30～50 absorbed on the surface of AuNPs film with HRP employed as blocking reagent to form one CEA immunosensor detection of carbamide peroxide(CP),and HRP could enhance the sensitivity of immunosensor.After the immu-nosensor was incubated with CEA solution at 37℃ for 30 min,the electron transfer access of CuL to CP was partly inhibited,which lead to a linear decrease of the catalytic efficiency to CP in pH 6.5 phosphate buffer solution (PBS),the decrease percentage of current had a linear relationship with the concentration of CEA between 0.1 and 80 ns/mL.Under optimal conditions,the detection limit for CEA is 0.052 ng/mL(3σ).This method simplifies the detection system.It has a high sensitivity and wide detection range for clinical immunoassay of CEA in pa-tients' serums.