Au@Zr-based metal-organic framework composite as an immunosensing platform for determination of hepatitis B virus surface antigen.

An ultrasensitive electrochemical immunosensor has been prepared using an immunofunctionalized zirconium (Zr)-based metal-organic framework (MOF) with gold (Au) decoration Au@UiO-66(NH) composite-coated glassy carbon electrode (GCE) for the determination of infectious hepatitis B surface antigen (HBsAg). We fabricated GCE with specific composite via immune-functionalization using anti-HBsAg with Au nanoparticles embedded in UiO-66(NH). The electrochemical sensing performance of the immunofunctionalized Au@UiO-66(NH)/GCE with HBsAg was characterized by cyclic voltammetry and differential pulse voltammetry. Under optimized conditions, there was a linear dynamic relationship in the buffer system between the electrical signal and HBsAg levels over the range 1.13 fg mL-100 ng mL (R = 0.999) with a detection limit of 1.13 fg mL. The total analysis time was 15 min per sample. Further validations were performed with HBsAg-spiked human serum samples, and similar detection limits as in the buffer system were observed with reduced signal intensities at lower concentrations of HBsAg (1, 10, and 100 fg mL) and minimal interference. The HBsAg electrochemical immunosensing assay had good selectivity and excellent reproducibility, thereby indicating its significant potential in the super-fast diagnosis of hepatitis B.