Amperometric Electrochemical Platform for Hydrazine Determination Exploiting Reduced Graphene Oxide, Co(Salophen) and DNA: Application in Pharmaceutical Formulations Samples

The present work presents the development of a sensitive and selective amperometric sensor for the determination of hydrazine (HZ) in pharmaceutical formulations using a glassy carbon electrode (GCE) modified with a composite based on Co(Salophen), reduced graphene oxide (rGO) and deoxyribonucleic acid (DNA). The rGO/Co(Salophen)/DNA composite was characterized by using Fourier-transform infrared spectroscopy (FTIR), cyclic voltammetry, and amperometry. The proposed platform presented a well-defined voltammetric profile with a redox couple around 0.32 V vs. Ag/AgCl which showed excellent catalytic activity towards HZ oxidation. The peak current of HZ electrochemical oxidation on the proposed electrochemical platform have changed linearly with the HZ concentration in the range from 2 to 364 µmol L-1. The proposed platform presented sensitivity, limit of detection, and limit of quantification of 0.056 µA L µmol-1, 0.54 µmol L-1, and 1.64 µmol L-1 to HZ, respectively. The relative standard deviation for eight determinations using a solution of 50 µmol L-1 HZ was 0.85%. The proposed sensor was successfully applied for the determination of HZ in pharmaceutical formulations, and the recovery tests showed a good accuracy with recovery percentage between 99 and 101%.

本研究开发了一种灵敏且选择性优异的安培传感器，用于药物制剂中肼（hydrazine, HZ）的定量检测，该传感器采用基于钴-萨伦（Co(Salophen)）、还原氧化石墨烯（reduced graphene oxide, rGO）与脱氧核糖核酸（deoxyribonucleic acid, DNA）的复合物修饰玻碳电极（glassy carbon electrode, GCE）制备而成。采用傅里叶变换红外光谱法（Fourier-transform infrared spectroscopy, FTIR）、循环伏安法以及安培法对制备的rGO/Co(Salophen)/DNA复合物进行了表征。所构建的传感平台呈现出清晰的伏安特性曲线，在相对于Ag/AgCl参比电极约0.32 V处存在一对氧化还原峰，对肼的氧化过程展现出极佳的催化活性。在该电化学传感平台上，肼的电化学氧化峰电流与其浓度在2~364 µmol·L⁻¹范围内呈良好的线性关系。该传感平台对肼的灵敏度、检测限与定量限分别为0.056 µA·L·µmol⁻¹、0.54 µmol·L⁻¹以及1.64 µmol·L⁻¹。采用50 µmol·L⁻¹的肼溶液进行8次平行测定，所得相对标准偏差为0.85%。本研究构建的安培传感器已成功应用于药物制剂中肼的定量检测，加标回收实验结果显示其准确度优异，回收率介于99%~101%之间。