Enhancing electrochemical detection of dopamine via dumbbell-like FePt-Fe3O4 nanoparticles.

We synthesize dumbbell-like FePt-Fe3O4 nanoparticles (NPs) and study their electrocatalytic oxidation and sensing of dopamine (DA). The FePt and Fe3O4 NPs are strongly coupled in the dumbbell structure and as a result, the dumbbell FePt-Fe3O4 NPs show the best activity for DA oxidation with the DA detection limit reaching 1 nM. They are used successfully to monitor the DA concentration increase induced by K+-stimulation of PC12 cells. Our data show that an electrode modified with dumbbell-like FePt-Fe3O4 NPs can serve as the most sensitive probe for real-time quantitative detection of DA in a neurological environment.