Department of Chemistry, Shanghai University, Shanghai 200444, PR China.
Bioelectrochemistry. 2012 Aug;86:38-45. doi: 10.1016/j.bioelechem.2012.01.008. Epub 2012 Feb 1.
A novel Au-nanoparticles/poly-eriochrome black T film modified glassy carbon electrode (AuNPs/PEBT/GCE) was constructed for the simultaneous determination of l-cysteine (L-Cys) and l-tyrosine (L-Tyr) by differential pulse voltammetry. Fourier transform infrared spectra and electrochemical impedance spectroscopy indicate that the PEBT film was successfully polymerized on the surface of GCE and the film efficiently decreased the charge transfer resistance value of electrode and improved the electron transfer kinetic between analytes and electrode. The scanning electron microscope image shows that the immobilized AuNPs were spherical in shape and enhanced the electrical conductivity of PEBT film. In addition, PEBT film increased the oxidation currents of analytes four times when compared to bare GCE, and the AuNPs separated the oxidation potentials of L-Cys and L-Tyr by 488 mV while bare GCE failed to resolve them. The amperometry results exhibit that the electrocatalytic currents increased linearly with L-Cys concentrations in the range 0.05-100 μM (r=0.9981), and the detection limits of L-Cys and L-Tyr were 8 nM and 10 nM (S/N=3), respectively. With high sensitivity and selectivity, the proposed electrochemical sensor provides a simple method for simultaneous determination of L-Cys and L-Tyr.
一种新型的金纳米粒子/聚曙红黑 T 修饰玻碳电极（AuNPs/PEBT/GCE）被构建用于通过差分脉冲伏安法同时测定 L-半胱氨酸（L-Cys）和 L-酪氨酸（L-Tyr）。傅里叶变换红外光谱和电化学阻抗谱表明，PEBT 膜成功地聚合在 GCE 表面，并且该膜有效地降低了电极的电荷转移电阻值，并提高了分析物与电极之间的电子转移动力学。扫描电子显微镜图像表明，固定的 AuNPs 呈球形，并增强了 PEBT 膜的电导率。此外，与裸 GCE 相比，PEBT 膜将分析物的氧化电流增加了四倍，而 AuNPs 将 L-Cys 和 L-Tyr 的氧化电位分离了 488 mV，而裸 GCE 则无法将它们分辨出来。安培法结果表明，电催化电流在 0.05-100 μM 的范围内与 L-Cys 浓度呈线性关系（r=0.9981），L-Cys 和 L-Tyr 的检测限分别为 8 nM 和 10 nM（S/N=3）。该电化学传感器具有高灵敏度和选择性，为同时测定 L-Cys 和 L-Tyr 提供了一种简单的方法。
