Fabrication of horseradish peroxidase immobilized poly(N-[3-(trimethoxy silyl)propyl]aniline) gold nanorods film modified electrode and electrochemical hydrogen peroxide sensing

We report a simple and one-pot procedure for the simultaneous immobilization of poly(N-[3-(trimethoxy sily)propyl[aniline (PTMSPA) and horseradish peroxidase (HRP) on gold nanorods (GNRs) to yield HRP/PTMSPA@GNRs. HRP/PTMSPA@GNR was well characterized by field emission scanning electron microscopy and UV-visible spectroscopy. High resolution image of HRP/PTMSPA@GNR attributes GNRs are welded/connected to one another through the surface coated PTMSPA. Direct electron transfer was achieved at HRP/PTMSPA@GNR with an electron transfer rate constant (k(s)) of 3.2 +/- 0.1 s(-1). Cyclic voltammograms of H2O2 at HRP/PTMSPA@GNR modified electrode exhibited a stable reduction peak at approximately -0.25 V. Amperometric response of HRP/PTMSPA@GNR modified electrode showed quick response (<5 s) for the reduction of H2O2. HRP/PTMSPA@GNR showed wide linear range from 1 x 10(-5) to 1 x 10(-3) M with detection limit (0.06 mu M) (S/N =3). HRP/PTMSPA@GNR modified electrode exhibited high selectivity with sensitivity (0.021 mu A/mu M) toward H2O2. (C) 2013 Elsevier Ltd. All rights reserved.