Mathebe Ntlatseng G R, Morrin Aoife, Iwuoha Emmanuel I
Department of Chemistry, University of the Western Cape, P/Bag X17, Bellville 7535, South Africa.
Talanta. 2004 Sep 8;64(1):115-20. doi: 10.1016/j.talanta.2003.11.050.
An amperometric biosensor was prepared by in situ deposition of horseradish peroxidase (HRP) enzyme on a polyaniline (PANI)-doped platinum disk electrode. The PANI film was electrochemically deposited on the electrode at 100mVs(-1)/Ag-AgCl. Cyclic voltammetric characterization of the PANI film in 1M HCl showed two distinct redox peaks, which prove that the PANI film was electroactive and exhibited fast reversible electrochemistry. The surface concentration and film thickness of the adsorbed electroactive species was estimated to be 1.85x10(-7)molcm(-2) and approximately 16nm, respectively. HRP was electrostatically immobilized onto the surface of the PANI film, and voltammetry was used to monitor the electrocatalytic reduction of hydrogen peroxide under diffusion-controlled conditions. Linear responses over the concentration range 2.5x10(-4) to 5x10(-3)M were observed. Spectroelectrochemistry was used to monitor the changes in UV-vis properties of HRP, before and after the catalysis of H(2)O(2). The biosensor surface morphology was characterized by scanning electron microscopy (SEM) using PANI-doped screen-printed carbon electrodes (SPCEs) in the presence and absence of (i) peroxidase and (ii) peroxide. The SEM images showed clear modifications of the conducting film surface structure when doped with HRP, as well as the effect of hydrogen peroxide on the morphology of biosensor.
通过将辣根过氧化物酶（HRP）原位沉积在聚苯胺（PANI）掺杂的铂盘电极上制备了一种电流型生物传感器。聚苯胺膜在100mV s(-1)/Ag - AgCl条件下电化学沉积在电极上。在1M HCl中对聚苯胺膜进行循环伏安表征显示出两个明显的氧化还原峰，这证明聚苯胺膜具有电活性且表现出快速可逆的电化学性质。吸附的电活性物质的表面浓度和膜厚度估计分别为1.85×10(-7) mol cm(-2)和约16nm。HRP通过静电作用固定在聚苯胺膜表面，并使用伏安法监测在扩散控制条件下过氧化氢的电催化还原。在2.5×10(-4)至5×10(-3) M的浓度范围内观察到线性响应。采用光谱电化学法监测H(2)O(2)催化前后HRP的紫外 - 可见性质变化。使用聚苯胺掺杂的丝网印刷碳电极（SPCE），通过扫描电子显微镜（SEM）对生物传感器表面形态进行表征，分别考察了（i）有无过氧化物酶和（ii）有无过氧化物的情况。SEM图像显示，掺杂HRP时导电膜表面结构有明显变化，同时也显示了过氧化氢对生物传感器形态的影响。
