Probing trace of intracellularly-originated hydrogen peroxide based Pt-Cd bimetallic nanozyme on an enzyme-free...

Measurement of endogenous cellular hydrogen peroxide (H₂O₂) can provide information on cellular status, and help to understand cellular metabolism and signaling processes, thus contributing to elucidation of disease mechanisms and new diagnostics/therapeutic approaches.

In this work, Pt-Cd bimetallic nanozyme was successfully prepared via the solvothermal synthetic method for sensitive detection of H₂O₂. The synthesized Pt-Cd bimetallic nanozyme could exhibited good electrochemical activity. Then, the materials were analyzed for the electrochemical properties and catalytic properties of H₂O₂ by cyclic voltammetry and chronoamperometry, respectively. Results indicated that the synthesized nanozyme had superior sensitivity (295 μA⸳mM^-1⸳cm^-2) and selectivity toward H₂O₂ with a detection limit of 0.21 μM. Further, the Pt-Cd bimetallic nanozyme displayed good electrochemical properties compared to platinum catalysts alone. The application was extended to determine the produced H₂O₂ from human hepatocellular carcinoma cells (HepG2) and normal hepatocyte (LO2) samples after ascorbic acid stimulation, thus enabling the early warning of cellular carcinogenesis.

This strategy promises simple, rapid, inexpensive and effective electrochemical sensing and provides a new pathway for the synthesis of bimetallic nanozymes to construct an electrochemical sensor for the sensitive detection of H₂O₂.