| Summary: | Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) is an essential analyte for detecting neurodegenerative diseases and inflammatory processes and plays a crucial role in pharmaceuticals, the food industry, and environmental monitoring. However, conventional H<sub>2</sub>O<sub>2</sub> detection methods have drawbacks such as lengthy analysis times, high costs, and bulky equipment. Non-enzymatic sensors have emerged as promising alternatives to overcome these limitations. In this research, we introduce a simple, portable, and cost-effective non-enzymatic sensor that uses carbon black (CB) and silver nanoparticle-modified δ-FeOOH (Ag/δ-FeOOH) integrated into a disposable electrochemical cell (DCell). Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and electrochemical impedance spectroscopy (EIS) confirmed successful CB and Ag/δ-FeOOH immobilization on the DCell working electrode. Electrochemical investigations revealed that the DCell-CB//Ag/δ-FeOOH sensor exhibited an approximately twofold higher apparent heterogeneous electron transfer rate constant than the DCell-Ag/δ-FeOOH sensor, capitalizing on CB’s advantages. Moreover, the sensor displayed an excellent electrochemical response for H<sub>2</sub>O<sub>2</sub> reduction, boasting a low detection limit of 22 µM and a high analytical sensitivity of 214 μA mM<sup>−1</sup> cm<sup>−2</sup>. Notably, the DCell-CB//Ag/δ-FeOOH sensor exhibited outstanding selectivity for H<sub>2</sub>O<sub>2</sub> detection, even in potential interferents such as dopamine, uric acid, and ascorbic acid. Furthermore, the sensor has the right qualities for monitoring H<sub>2</sub>O<sub>2</sub> in complex biological samples, as evidenced by H<sub>2</sub>O<sub>2</sub> recoveries ranging from 92% to 103% in 10% fetal bovine serum. These findings underscore the considerable potential of the DCell-CB//Ag/δ-FeOOH sensor for precise and reliable H<sub>2</sub>O<sub>2</sub> monitoring in various biomedical and environmental applications.
|
|---|