Green synthesis and characterization of Ag nanoparticles in a phytic acid/ascorbic acid/sodium hydroxide system and their application in the electrochemical detection of H2O2

Abstract

Hydrogen peroxide (H₂O₂), as one of the most ubiquitous compounds, is widely used in many fields and performs important functions in physiological processes. Therefore, it is of great practical significance to develop a rapid and accurate detection method for trace H₂O₂ to avoid its harmful effects to human health and for environmental safety and medical diagnosis. In particular, Ag nanoparticles (Ag NPs) show great potential in the field of electrochemical H₂O₂ sensors because of their excellent electrocatalytic reduction activity to H₂O₂. Herein, plant extracts (phytic acid (PA) and ascorbic acid (AA)) obtained from biological methods were introduced into chemical synthesis methods, and a green synthesis system for controllable preparation of Ag NPs using PA/AA/NaOH was established. Moreover, the synthesis process and mechanism of PA coated Ag NPs (Ag NPs@PA) were described by means of XPS, particle size analysis and a schematic diagram. Furthermore, a simple electrochemical H₂O₂ sensor was constructed by modifying Ag NPs@PA onto the surface of a glassy carbon electrode (GCE). The sensor exhibited the characteristics of a quick response (∼0.3 s), good linear relationship, a wide linear range (1–4 μM, 4–6000 μM) and a low detection limit (1.5 μM) for H₂O₂ detection, showing excellent comprehensive detection performance. Its sensing mechanism and dynamic process were also investigated. In addition, the sensor presented outstanding selectivity, anti-interference, repeatability, reproducibility and feasibility of practical applications, providing a new strategy for the quantitative detection of H₂O₂.