摘要
采用滴涂和电聚合法制备了聚L-半胱氨酸/乙炔黑修饰玻碳电极（L-Cys/AB/GCE）。用电化学交流阻抗法和计时库仑法研究了该修饰电极表面的界面性质。此外,还通过循环伏安法（CV）研究了对苯二酚（HQ）在该修饰电极上的电化学行为。阻抗图谱说明L-Cys/AB/GCE修饰膜的存在能够增加电子转移速度;计时库仑分析表明,L-Cys/AB/GCE的比表面积是裸电极的6倍;CV行为表明,L-Cys/AB/GCE对HQ氧化还原具有良好的电催化作用,响应的峰电流为裸电极的4倍,提高了检测HQ的灵敏度且峰电流与电位扫描速度的平方根呈良好的线性关系,相关系数R2为0.995~0.998,说明HQ在L-Cys/AB/GCE上的电化学反应过程是受扩散速度控制的过程。在支持电解质为0.1mol/L磷酸盐缓冲溶液（pH 7.0）的优化条件下,用差分脉冲伏安法（DPV）分析,HQ浓度在0.5~1 000μmol/L范围内,氧化峰的峰电流（Ipa）与浓度（c）呈良好的线性关系,相关系数R2为0.998,方法检出限为0.08μmol/L,由此建立了一种测定水样中HQ的方法。按照实验方法对环境水样中HQ进行测定,结果与高效液相色谱法基本一致,相对标准偏差（RSD,n=8）为2.3%~2.6%。
A poly（L-cysteine）/acetylene black modified glassy carbon electrode（L-Cys/AB/GCE）was prepared through drop coating method and electrochemical polymerization method,and the interfacial property of its surface was investigated by electrochemical alternating current impedance and chronocoulometry.Furthermore,the electrochemical behavior of hydroquinone（HQ）was investigated by cyclic voltammetry（CV）on this modified electrode.The impedance graph indicated that the existence for the modified film of L-cys/AB/GCE could accelerate the transfer of electron.The chronocoulometry graph showed that the specific surface area of L-cysteine/AB/GCE was six times of that of bare electrode.The behavior of CV implied that the L-Cys/AB/GCE had an excellent electrocatalytic effect for the oxidation and reduction of HQ with four times in peak current response relative to the bare sensor,which improved the detection sensitivity of HQ.For L-Cys/AB/GCE,its peak current had a good linear relationship with the square root of scanning rate with correlation coefficient R2=0.995-0.998,indicating that the electrochemical reaction of HQ on L-Cys/AB/GCE was controlled by the process of diffuse velocity.Under optimized condition with0.1mol/L phosphate buffer solution（PBS）at pH 7.0as the supporting electrolyte,the results of differential pulse voltammetry（DPV）indicated that the oxidation peak current（Ipa）of HQ showed a good linearity with its concentration（c）ranging from 0.5-1 000μmol/L with a correlation coefficient（R）of 0.998 and detection limit of 0.08μmol/L.Therefore,a new method for determination of HQ in water sample was established.When this method was used for HQ determination in environmental water sample,the results was consistent with those by high performance liquid chromatography,and the relative standard deviation（RSD,n=8）was 2.3%-2.6%.
出处
《冶金分析》
CAS
CSCD
北大核心
2016年第9期19-24,共6页
Metallurgical Analysis
基金
国家自然科学基金资助项目(21305119)
国家级大学生创新创业训练计划资助项目(201510477014)
