College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, China.
Department of Chemical Engineering, Jessore University of Science and technology, Jessore, 7408, Bangladesh.
Mikrochim Acta. 2018 Aug 30;185(9):439. doi: 10.1007/s00604-018-2979-z.
A glassy carbon electrode (GCE) was modified with poly(L-arginine) (P-Arg), reduced graphene oxide (rGO) and gold nanoparticle (AuNP) to obtain an electrode for simultaneous determination of dopamine (DA), serotonin (5-HT) and L-tryptophan (L-Trp) in the presence of ascorbic acid (AA). The modified GCE was prepared via subsequent 'layer-by-layer' deposition using an electrochemical technique. The surface morphology of the modified electrode was studied by scanning electron microscopy, and electrochemical characterizations were carried out via cyclic voltammetry and electrochemical impedance spectroscopy. The modified electrode showed excellent electrocatalytic activity toward DA, 5-HT and L-Trp at pH 7.0. Figures of merit for the differential pulse voltammetric reponse are as follows: (a) Response to DA is linear in two intervals, viz. 1.0-50 nM and 1.0-50 μM DA concentration range, the typical working voltage is 202 mV (vs. Ag/AgCl), and the detection limit is 1 nM (at an S/N ratio of 3). For 5-HT, the respective data are 10 to 500 nM and 1.0 to 10 μM, 381 mV, and 30 nM. For L-Trp, the respective data are 10-70 nM and 10-100 μM, 719 mV, and 0.1 μM. The modified GCE is fairly selective. It was successfully applied to the simultaneous determination of DA, 5-HT, and L-Trp in spiked urine samples, and high recovery rates were found. Graphical abstract Schematic presentation of the voltammetric sensor based on a glassy carbon electrode modified with poly(L-arginine), reduced graphene oxide (rGO) and gold nanoparticle (GCE/P-Arg/ErGO/AuNP) for simultaneous determination of dopamine (DA), serotonin (5-HT) and L-tryptophan (L-Trp).
玻碳电极（GCE）经聚 L-精氨酸（P-Arg）、还原氧化石墨烯（rGO）和金纳米粒子（AuNP）修饰，用于在抗坏血酸（AA）存在下同时测定多巴胺（DA）、5-羟色胺（5-HT）和 L-色氨酸（L-Trp）。通过电化学技术，采用后续的“层层”沉积法制备修饰后的 GCE。通过扫描电子显微镜研究了修饰电极的表面形态，并通过循环伏安法和电化学阻抗谱进行了电化学表征。修饰后的电极对 DA、5-HT 和 L-Trp 具有优异的电催化活性，在 pH 7.0 下。差分脉冲伏安响应的定量参数如下：（a）DA 的响应在两个区间内呈线性，即 1.0-50 nM 和 1.0-50 μM DA 浓度范围，典型工作电压为 202 mV（相对于 Ag/AgCl），检测限为 1 nM（信噪比为 3）。对于 5-HT，分别为 10 到 500 nM 和 1.0 到 10 μM、381 mV 和 30 nM。对于 L-Trp，分别为 10-70 nM 和 10-100 μM、719 mV 和 0.1 μM。修饰后的 GCE 具有相当的选择性。它成功地应用于同时测定加标尿样中的 DA、5-HT 和 L-Trp，发现回收率较高。图表摘要 基于玻碳电极修饰聚 L-精氨酸、还原氧化石墨烯（rGO）和金纳米粒子（GCE/P-Arg/ErGO/AuNP）的伏安传感器用于同时测定多巴胺（DA）、5-羟色胺（5-HT）和 L-色氨酸（L-Trp）的示意图。
