A novel non-enzyme hydrogen peroxide sensor based on catalytic reduction property of silver nanowires

• Use of silver nanowires in fabrication of novel non-enzyme H2O2 sensor.
• The silver nanowires exhibited good catalytic ability to the reduction of H2O2.
• Cyclic voltammetry scanning favored to activate electrochemical properties.
• Sensor showed favorable performances at a low potential of −0.2 V vs. Ag/AgCl.

A novel strategy to fabricate a hydrogen peroxide (H2O2) sensor was developed based on silver nanowires modified Pt electrode. The sensor was fabricated by simple casting of silver nanowires (Ag NWs) aqueous solution on a Pt electrode. Silver nanowires were synthesized by an l-cysteine-assisted poly (vinyl pyrrolidone) (PVP)-mediated polyol route. UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to investigate the prepared nanowires. The electrochemical properties of H2O2 sensor were evaluated by cyclic voltammetry (CV) and chronoamperometry. The as-obtained silver nanowires exhibited favorable electroreduction activity toward H2O2, and results indicated that the Ag NWs modified Pt (Ag NWs/Pt) electrode might be gifted from CV scanning with higher surface area and more active sites that afford more effective surface exposure in the electrode–electrolyte interface and consequently improved electrochemical properties. At the applied potential of −0.2 V vs. Ag/AgCl, the Ag NWs/Pt electrode as an enzyme-free sensor exhibited a wide linear range of 0.5 μM–30 mM to H2O2, with a remarkable sensitivity of 9.45 μA/mM, a detection limit of 0.2 μM estimated at a signal-to-noise ratio of 3 and fast response time (within 5 s). Moreover, it showed good reproducibility, anti-interferant ability and long-term stability. The excellent performance of the sensor might be attributed to the well-defined silver nanowires with special catalytic activity.

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