This paper presents the application of polyglycine-modified graphene paste electrode (PGMGPE) for the electrochemical detection of Hg (II) and Pb (II) ions in the water and biological samples. The developed electrode was characterized by field emission scanning electron microscopy. Electrochemical techniques such as cyclic voltammetry and differential pulse voltammetry were used to study the behavior of metal ions. The modification process improves the electrochemical behavior of heavy metal ions. The peak current varied linearly with the increase of the concentration leading to a detection limit of 6.6 μM (Hg (II)) and 0.8 μM (Pb (II)), respectively. The developed electrode exhibits good sensitivity, selectivity, stability, and lower detection limit, and was successfully applied to the determination of heavy metal ions in water and biological samples with a good recovery range.

中文翻译：

---

新型聚合物改性石墨烯电化学传感器的制备，用于测定水和生物样品中的汞和铅离子

本文介绍了聚甘氨酸修饰的石墨烯糊状电极 (PGMGP​​E) 在电化学检测水和生物样品中的 Hg (II) 和 Pb (II) 离子中的应用。开发的电极通过场发射扫描电子显微镜进行表征。电化学技术如循环伏安法和微分脉冲伏安法被用来研究金属离子的行为。改性过程改善了重金属离子的电化学行为。峰值电流随着浓度的增加呈线性变化，导致检测限分别为 6.6 μM (Hg (II)) 和 0.8 μM (Pb (II))。所开发的电极具有良好的灵敏度、选择性、稳定性和较低的检出限，