Dumbbell-like PtPd–Fe3O4 Nanoparticles for Enhanced Electrochemical Detection of H2O2

Dumbbell-like PtxPd100–x–Fe3O4 nanoparticles (NPs) were synthesized and studied for electrocatalytic reduction and sensing of H2O2. In 0.1 M phosphate buffered saline (PBS) solution, the 4–10 nm PtxPd100–x–Fe3O4 NPs showed the Pt/Pd composition-dependent catalysis with Pt48Pd52–Fe3O4 NPs having the best activity. The Pt48Pd52–Fe3O4 NPs were tested for H2O2 detection, and their H2O2 detection limit reached 5 nM, which was suitable for monitoring H2O2 generated from Raw 264.7 cells. These dumbbell-like PtPd–Fe3O4 NPs are the most sensitive probe ever reported and can be used to achieve real-time quantitative detection of H2O2 in biological environment for biological and biomedical applications.