Designing a modified electrode based on La3+-doped ZnO nanoflowers and guar-gum application to electrochemical detection of ascorbic acid

The quantitative detection of drug content constitutes a permanent preoccupation for research in various fields [1]. It is well established that ascorbic acid (AA) is widely used in food, pharmaceutical industry and clinic medicine [2]. Ascorbic acid is an important antioxidant widely present in biological systems, which is an essential substance to maintain normal physiological function of human body. Abnormal contents of ascorbic acid may cause several symptoms, including fatigue, infertility and scurvy [3]. In this work, an easy method was employed to successfully develop La3+-doped ZnO nanoflowers and guar-gum (GG) modified screen printed electrode (La3+/ZnO/GG/SPE), and La3+/ZnO/GG/SPE was applied for the electrochemically detection of ascorbic acid (AA). The electrochemical methods, such as cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV) were used to evaluate the electrochemical performances toward ascorbic acid on the La3+/ZnO/GG/SPE. Good linearship was observed for ascorbic acid in the ranges of 1.0–700.0 μM, with the detection limits of 0.03 μM. Moreover, this sensor proved favorable to simultaneously determine ascorbic acid and acetaminophen. Finally, the modified electrode has fairly good performance during the employment of real sample analysis to determine the content of ascorbic acid. These results 14th Annual Electrochemistry Seminar of Iran Materials and Energy Research Center (MERC), 12- 13 Dec, 2018 32 indicate that the La3+-doped ZnO nanoflowers are supposed to be a promising material in the electrochemical determination of ascorbic acid and acetaminophen in real samples.