Novel cathodic photoelectrochemical immnuosensor with high sensitivity based on 3D AuNPs/ZnO/Cu2O heterojunction nanowires

Key Words:Gold compounds;Antigens - Copper oxides - Gold nanoparticles - Heterojunctions - II-VI semiconductors - Immunology - Metal cladding - Nanowires - Photocathodes - Photoelectrochemical cells - Silver compounds - Zinc oxide

Abstract:A promising electrode with three-dimensional (3D) AuNPs/ZnO/Cu2O heterojunction nanowires (NWs) was developed and applied as photocathode for sensitive photoelectrochemical (PEC) immunoassay toward carcinoembryonic antigen (CEA, Ag). Firstly, Cu2O NWs were grown in situ on a Cu foil substrate to provide large specific surface area. After the modification of ZnO layer on the Cu2O NWs, the ZnO/Cu2O heterojunction structure was formed, which can increase the harvest of light energy and play a role in charge separation and transport. With further modification of gold nanoparticles (AuNPs), the good electric conductivity of the AuNPs would induce enhanced charge separation between Cu2O and ZnO. Thus, the photocurrent response of the prepared 3D AuNPs/ZnO/Cu2O NWs photocathode was significantly improved by synergistic effects of each element in the 3D structure. As a result, the fabricated cathodic PEC immunosensor exhibited high sensitivity with a low detection limit of 0.36 pg/mL (S/N = 3) for CEA detection. Furthermore, good specificity and well anti-interference capability toward real sample detection was achieved. ? 2019 Elsevier Ltd

Volume:318

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Translation or Not:no