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 (H