Construction of highly sensitive electrochemical immunosensor based on Au and Co3O4 nanoparticles functionalized Ni/Co bimetal conductive MOF for quantitative detection of HBsAg.

[Display omitted] • Ni/Co c-MOFs decoration with Au and Co 3 O 4 NPs were synthesized by a facile method. • The Au 3 @Co 3 O 4 NPs/Ni 1 Co 2 (HITP) immunosensor was optimized toward HBsAg detection. • High-performance of immunosensor can be ascribed to the synergistic effect. • The optimum immunosensor exhibits a low detection limit of 15 fg mL−1 for HBsAg. Herein, highly sensitive electrochemical immunosensor based on noble metal and metal oxide nanoparticles functionalized bimetal conductive metal–organic frameworks (c-MOFs) was proposed toward HBsAg detection. The nanorod-like architecture of Ni 3 (HITP) 2 c-MOFs was synthesised via a simple and facile route, followed by dopant coble ions formation cobaltosic oxide (Co 3 O 4) nanoparticles decorated bimetal NiCo(HITP) c-MOFs nanocomposites. Benefiting from large specific surface area, high electrical conductivity and abundant active sites of desirable nanostructures, the resultant Co 3 O 4 NPS/NiCo(HITP) bimetal c-MOFs nanostructure exhibits fast electron transfer capability and effective specific binding between antigen and antibody. Meanwhile, different amounts of Au nanoparticles were further functionalized on Co 3 O 4 NPS/NiCo(HITP) nanocomposites to further improve the electrochemical properties. Under optimum condition, the as-proposed Au@Co 3 O 4 NPS/NiCo(HITP) electrochemical immunosensor exhibits superior sensing performances toward HBsAg including wide linear response range from 1 pg mL−1 to 100 ng mL−1 and low detection limit of 15 fg mL−1 (S/N = 3). Meanwhile, the as-fabricated electrochemical immunosensors also displays outstanding selectivity, repeatability and stability. Besides, quantitative detection of HBsAg also achieves satisfactory results in real sample detection. Thereby, our work not only provides a promising strategy to construct highly sensitive electrochemical immunosensor using hybrid c-MOFs nanomaterials but also presents a potential application in the early diagnosis of hepatitis B-related diseases. [ABSTRACT FROM AUTHOR]