PdPtCu mesoporous nanocube-based electrochemical sandwich immunosensor for detection of HIV-p24.

The construction of simple, stable, low-cost and reproducible enzyme-free electrochemical biosensors can effectively avoid the problem of signal attenuation caused by enzyme inactivation. Hererin, we prepared a novel nanoenzymes PdPtCu mesoporous nanocubes (MNCs) to construct a label-free sandwich electrochemical immunosensor for the highly sensitivity detection of HIV-p24. PdPtCu MNCs have excellent peroxidase activity against hydrogen peroxide (HO) due to their synergistic ternary composition, large surface area and ability to penetrate mesoporous channels. Moreover, highly conductive and biocompatible gold nanoparticles@graphene oxide (AuNPs@GO) was introduced as a substrate to modify a glassy carbon electrode (GCE). Owing to the excellent electrochemical performance of the PdPtCu MNCs and AuNPs@GO, the developed immunosensors exhibited a good linear response from 0.04 pg/mL to 100 ng/mL with a low detection limit of 20 fg/mL. In addition, the established method exhibited excellent practical performance in human serum. This novel strategy provides a promising platform for ultrasensitive detection of the HIV-p24 in the field of clinical diagnostics.