The fabrication of sensitive, fast, cost-effective and eco-friendly electrochemical sensors is essential for monitoring analytes of biomedical, environmental and pharmaceutical interests. Herein, we report the simultaneous electroreduction and deposition of graphene oxide (GO) to form electrochemically reduced graphene oxide (ERGO) onto a glassy carbon electrode (GCE) represented as GCE-ERGO. Onto the GCE-ERGO, cobalt (II) tetra-amino phthalocyanine was electropolymerized to form a stable GCE-ERGO/polyCoTAPc. The sensing surface, GCE-ERGO/polyCoTAPc, was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques to ascertain its electron transfer and conducting properties. The modifier surface functional groups and composition were confirmed using infrared spectroscopy and energy-dispersive X-ray spectroscopy. The prepared sensing electrode displayed enhanced electrocatalytic activity towards ferri/ferrocyanide {[Fe(CN)₆]^3−/4−} as a redox probe. GCE-ERGO/polyCoTAPc was further used for ultrasensitive simultaneous detection and determination of dopamine (DA) and paracetamol (PA). The electrocatalytic peak currents for DA and PA were greatly enhanced with an oxidation potential difference of 264 mV, wide enough for simultaneous determination. Using differential pulse voltammetry (DPV), the electrocatalytic oxidation peak currents of DA and PA at GCE-ERGO/polyCoTAPc showed linear dependence with the changes in concentrations up to 100 µM for DA and up to 90 µM for PA. The limits of detection (LOD) values were 0.095 µM and 0.10 µM using a signal-to-noise (S/N) ratio of 3 for DA and PA, respectively. The GCE-ERGO/polyCoTAPc displayed excellent sensitivity of 8.39 µA µM⁻¹ cm⁻² for DA and 1.32 µA µM⁻¹ cm⁻² for PA. The fabricated ultrasensitive electrochemical sensor was successfully used for the determination of DA and PA in synthetic urine samples with excellent percentage recoveries.

灵敏、快速、经济高效且环保的电化学传感器的制造对于监测生物医学、环境和制药利益的分析物至关重要。在此，我们报告了氧化石墨烯 (GO) 的同步电还原和沉积，以在表示为 GCE-ERGO 的玻碳电极 (GCE) 上形成电化学还原氧化石墨烯 (ERGO)。在 GCE-ERGO 上，钴 (II) 四氨基酞菁被电聚合以形成稳定的 GCE-ERGO/polyCoTAPc。传感表面 GCE-ERGO/polyCoTAPc 使用循环伏安法 (CV) 和电化学阻抗谱 (EIS) 技术进行表征，以确定其电子转移和导电特性。使用红外光谱和能量色散 X 射线光谱确认改性剂表面官能团和组成。制备的传感电极对铁/亚铁氰化物{[Fe(CN)₆ ] ^{3− / 4−} } 作为氧化还原探针。GCE-ERGO/polyCoTAPc 进一步用于多巴胺 (DA) 和扑热息痛 (PA) 的超灵敏同时检测和测定。DA 和 PA 的电催化峰值电流大大增强，氧化电位差为 264 mV，足以同时测定。使用差分脉冲伏安法 (DPV)，GCE-ERGO/polyCoTAPc 的 DA 和 PA 的电催化氧化峰值电流显示线性依赖性，DA 浓度变化高达 100 µM，PA 浓度变化高达 90 µM。对于 DA 和 PA，使用 3 的信噪比 (S/N) 时，检测限 (LOD) 值分别为 0.095 µM 和 0.10 µM。GCE-ERGO/polyCoTAPc 显示出 8.39 µA µM ⁻¹  cm ^{−2的出色灵敏度}对于 DA 和 1.32 µA µM ⁻¹  cm ⁻²对于 PA。所制造的超灵敏电化学传感器已成功用于测定合成尿液样品中的 DA 和 PA，并具有出色的回收率。