Facile synthesis of MoS2@Cu2O-Pt nanohybrid as enzyme-mimetic label for the detection of the Hepatitis B surface antigen.

An ultrasensitive sandwich-type electrochemical immunosensor was proposed for quantitative detection of hepatitis B surface antigen, which is a representative biomarker of the Hepatitis B virus. First, the porous graphene oxide/Au composites with good conductive ability were employed to accelerate the electron transfer on the electrode interface. Furthermore, the amino functionalized molybdenum disulfide @ cuprous oxide hybrid with coral morphology was prepared to combine platinum nanoparticles for achieving signal amplification strategy. The resulting nanocomposites (molybdenum disulfide @ cuprous oxide - platinum) demonstrated uniform coral morphology, which effectively improved the specific surface area available for loading the secondary antibody and the number of catalytically active sites, even also increased the electrical conductivity. Based on these advantages, this composite system yielded a superior electrocatalytic current response toward the reduction of hydrogen peroxide. In addition, porous graphene oxide/Au composites were used to modify the glassy carbon electrode, thereby presenting a large surface area and becoming biocompatible, for improving the loading capacity of the primary antibody. Under optimal conditions, we obtained a linear relationship between current signal and hepatitis B surface antigen concentration in the broad range from 0.5pg/mL to 200ng/mL, with a detection limit of 0.15pg/mL (signal-to-noise ratio of 3). These values are promising towards clinical applications.