Enhanced peroxidase-like properties of Au@Pt DNs/NG/Cu(2+) and application of sandwich-type electrochemical immunosensor for highly sensitive detection of CEA.

作者：Lv, Hui; Li, Yueyun^*; Zhang, Xiaobo; Gao, Zengqiang; Zhang, Chunyan; Zhang, Shuan; Dong, Yunhui

来源：Biosensors and Bioelectronics, 2018, 112: 1-7.

DOI：10.1016/j.bios.2018.04.025

• Au nanoparticles functionalized polydopamine
• Carcinoembryonic antigen
• Cubic Au@Pt dendritic nanomaterials
• Nitrogen-doped graphene
• Sandwich-type electrochemical immunosensor

Effective treatment of cancer depends upon the early detection of the tumor marker. Here, we report on the development of a new immunosensor for early detection of carcinoembryonic antigen (CEA). Cubic Au@Pt dendritic nanomaterials functionalized nitrogen-doped graphene loaded with copper ion (Au@Pt DNs/NG/Cu(2+)) with enhanced peroxidase-like properties was synthesized as labels to effectively capture and immobilize secondary anti-CEA. The Au@Pt DNs with more active surface area could efficiently enhance electrocatalysis for reduction of hydrogen peroxide (H(2)O(2)). Meanwhile, with good conductivity and large specific surface area, NG can immobilize a large amount of Au@Pt DNs. Furthermore, after adsorbed Cu(2+) can further promote the redox of H(2)O(2) and amplify the signal of the immunosensor. For the immobilization of primary antibodies, Au nanoparticles functionalized polydopamine (Au@PDA) were used as transducing materials to modify glassy carbon electrodes and enhance the electron transfer efficiently. Under optimal conditions, the immunosensor exhibited a satisfactory response to CEA with a limit detection of 0.167 pg/mL and linear detection range from 0.5 pg/mL to 50 ng/mL. Based on the high sensitivity and specificity of the immunosensor, we propose this multiple amplified biosensor for early detection of CEA.