表面蒸气溶胶-凝胶Al_2O_3薄膜电极上肌红蛋白的直接电化学研究

Direct electrochemistry of myoglobin in vapor-surface sol-gel deposition of alumina films

本文利用表面蒸气溶胶-凝胶沉积与层层组装技术相结合,成功制备了溶胶-凝胶三氧化二铝(SG-Al2O3)/肌红蛋白(Mb)层层组装薄膜修饰电极({SG-Al2O3/Mb}n)。通过实验确定了最优组装方式PG/PD-DA/{SG-Al2O3/Mb(pH 5.0)}n以及在表面蒸气溶胶-凝胶沉积过程中的最佳涂布水量2μL。考察了该薄膜修饰电极的循环伏安性质。实验表明:在pH 7.0缓冲溶液中,薄膜中的Mb在-0.34 V出现了一对可逆性良好的还原氧化峰,这是血红素辅基的电活性中心Fe(III)/Fe(II)氧化还原电对的特征峰,随着缓冲溶液pH值的增长,峰电位发生负移,式量电位E°'与pH值呈直线关系,其斜率为–42.4 mV/pH,随着扫描速度的增大,峰电流增大,且电流与扫描速度的平方根成正比。

{ SG-Al2O3/Mb} , films were assembled by alternate deposition of Al2O3 by vapor-surface sol-gel method from liquid alu- minum butoxide and Mb by adsorption from its solution. Optimization experiments were performed with different assembling mode and with various volume of water in deposition. The experimental results showed that the maximum CV reduction peak was observed with 2μL water and PG/PDDA/{ SG-Al2O3/Mb （pH 5.0） }, was the best assemble mode. Cyclic vohammetry of{ Al2O3/Mb}, film was monitored, a pair of well-de？ ned, nearly reversible redox peak was observed at about -0. 34V in pH 7.0 buffer, characteristic of Mb heine Fe（ III）/Fe（II） redox couples. With the increase of the pH value of buffer solution, the peak potential moves negative- ly, the relationship between E°′ and pH value is linear with a slope of-42.4mV/pH. Along with the increase of scan rate,the reduc- tion-oxidation peak current increases, and the current is proportional to the square root of the scan rate.