Ultrasensitive Detection of Hepatitis E Virus by Electrocatalytic Water Oxidation using Pt-Co3O4 Hollow Cages.

Sensitive virus detection method applicable for an early stage increases the probability of survival. Here, we develop a simple and rapid detection strategy for the detection of Hepatitis E virus (HEV) by an electrocatalytic water oxidation reaction (WOR) using Platinum (Pt)-incorporated cobalt (Co)-based zeolite imidazole framework (ZIF-67). The surface cavity of ZIF-67 enables the rich-loading of Pt NPs, and subsequent calcination etches the cavity, promoting the electrocatalytic activity of Pt-Co3O4 HCs. The Pt-Co3O4 HCs shows an excellent behavior for WOR due to the synergistic interaction of Pt and Co3O4, evaluated by voltammetry and chronoamperometry. The synthesized Pt-Co3O4 HCs are conjugated with Anti-HEV antibody (Ab@Pt-Co3O4 HCs), the electrocatalytic activity of Ab@Pt-Co3O4 HCs is combined with antibody-conjugated magnetic nanoparticles (MNPs) for HEV detection by magneto-and-nanocomposite sandwich immunoassay. The sensor is challenged to detect the HEV in spiked serum samples and HEV G7 genotypes collected from the cell culture supernatant, reaching a low limit of detection down to 61 RNA copies mL-1. This work establishes a free-indicator one-step approach with the controlled design of Pt-Co3O4 HCs, which presents an effective WOR technique for virus detection in neutral pH solution, extending the electrocatalytic study in the future integrated biosensing systems.