Abstract
In this paper, vertically aligned Pt nanowire arrays (PtNWA) with different lengths and surface roughnesses were fabricated and their electrochemical performance toward hydrogen peroxide (H2O2) detection was studied. The nanowire arrays were synthesized by electroplating Pt in nanopores of anodic aluminum oxide (AAO) template. Different parameters, such as current density and deposition time, were precisely controlled to synthesize nanowires with different surface roughnesses and various lengths from 3 μm to 12 μm. The PtNWA electrodes showed better performance than the conventional electrodes modified by Pt nanowires randomly dispersed on the electrode surface. The results indicate that both the length and surface roughness can affect the sensing performance of vertically aligned Pt nanowire array electrodes. Generally, longer nanowires with rougher surfaces showed better electrochemical sensing performance. The 12 μm rough surface PtNWA presented the largest sensitivity (654 μA·mM−1·cm−2) among all the nanowires studied, and showed a limit of detection of 2.4 μM. The 12 μm rough surface PtNWA electrode also showed good anti-interference property from chemicals that are typically present in the biological samples such as ascorbic, uric acid, citric acid, and glucose. The sensing performance in real samples (river water) was tested and good recovery was observed. These Nafion-free, vertically aligned Pt nanowires with surface roughness control show great promise as versatile electrochemical sensors and biosensors.
Highlights
In recent years, there has been increasing demand for sensor design and development for H2O2 detection, due to the fact that H2O2 is a very important molecule that is involved in many important fields, such as disease diagnosis [1], environmental protection [2,3], food quality control [4,5], fuel cells [6,7], and the bleach and disinfectant industry [8,9,10,11]
The results demonstrate that the responses from citric acid (CA), glucose, ascorbic acid (AA) and uric acid (UA) are negligible compared to that was observed for 0.1 mM H2O2, indicating a high selectivity and good anti-interference properties of long rough structured Pt nanowire arrays (PtNWA) sensor
A one step electrodeposition method was applied to the synthesis of vertically aligned Pt nanowire arrays on an anodic aluminum oxide (AAO) template
Summary
There has been increasing demand for sensor design and development for H2O2 detection, due to the fact that H2O2 is a very important molecule that is involved in many important fields, such as disease diagnosis [1], environmental protection [2,3], food quality control [4,5], fuel cells [6,7], and the bleach and disinfectant industry [8,9,10,11]. Vapor-Liquid-Solid (VLS) technique [27], surfactant/polymer assisted chemical reduction [28], electroless deposition [29], and electroplating using nanoporous templates [30,31] Due to their high aspect ratio and unique surface properties, nanowires possess excellent electrochemical and catalytic performance. By controlling the electrodeposition time and current density, we synthesized PtNWAs with different surface roughnesses (smooth and rough) and various lengths (3, 6, and 12 μm), and investigated their electrochemical sensing characteristics through cyclic voltammetric and chronoamperometric measurements. Both the sensitivity and anti-interference properties of the vertically aligned nanowire electrodes were studied. Real water samples were used to test the potential application of these new nanowire-based electrochemical sensors
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