Highly accessible Pt nanodots homogeneously decorated on Au nanorods surface for sensing

Some nanostructures are reported to possess enzyme-mimetic activities similar to those of natural enzymes. Herein, highly-dispersed Pt nanodots on Au nanorods (HD-PtNDs@AuNRs) with mimetic peroxidase activity were designed as an active electrode modifier for fabrication of a hydrogen peroxide (H2O2) electrochemical sensor. The HD-PtNDs@AuNRs were synthesized by a seed-mediated growth approach and confirmed by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and UV-vis spectroscopy. The electrochemical and catalytical performances of HD-PtNDs@AuNRs towards H2O2 reduction were investigated in detail by cyclic voltammetry and amperometry. The HD-PtNDs@AuNRs modified electrode displayed a high catalytic activity to H2O2 at -0.10 V (versus SCE), a rapid response within 5 s, a wide linear range of 2.0-3800.0 μM, a detection limit of 1.2 μM (S/N=3), and a high sensitivity of 181 μA mM(-1) cm(-2). These results suggested a promising potential of fabricating H2O2 electrochemical sensor using HD-PtNDs@AuNRs.