Melo, W.E.R.; Nantes, K.S.; Ferreira, A.L.H.K.; Pereira, M.C.; Mattoso, L.H.C.; Faria, R.C.; Afonso, A.S. A Disposable Carbon-Based Electrochemical Cell Modified with Carbon Black and Ag/δ-FeOOH for Non-Enzymatic H2O2 Electrochemical Sensing. Electrochem2023, 4, 523-536.
Melo, W.E.R.; Nantes, K.S.; Ferreira, A.L.H.K.; Pereira, M.C.; Mattoso, L.H.C.; Faria, R.C.; Afonso, A.S. A Disposable Carbon-Based Electrochemical Cell Modified with Carbon Black and Ag/δ-FeOOH for Non-Enzymatic H2O2 Electrochemical Sensing. Electrochem 2023, 4, 523-536.
Melo, W.E.R.; Nantes, K.S.; Ferreira, A.L.H.K.; Pereira, M.C.; Mattoso, L.H.C.; Faria, R.C.; Afonso, A.S. A Disposable Carbon-Based Electrochemical Cell Modified with Carbon Black and Ag/δ-FeOOH for Non-Enzymatic H2O2 Electrochemical Sensing. Electrochem2023, 4, 523-536.
Melo, W.E.R.; Nantes, K.S.; Ferreira, A.L.H.K.; Pereira, M.C.; Mattoso, L.H.C.; Faria, R.C.; Afonso, A.S. A Disposable Carbon-Based Electrochemical Cell Modified with Carbon Black and Ag/δ-FeOOH for Non-Enzymatic H2O2 Electrochemical Sensing. Electrochem 2023, 4, 523-536.
Abstract
Hydrogen peroxide (H2O2) is an essential analyte for detecting neurodegenerative diseases and in-flammatory processes and plays a crucial role in pharmaceutical, food industry, and environmental monitoring. However, conventional H2O2 detection methods have drawbacks such as lengthy analysis time, high costs, and bulky equipment. Non-enzymatic sensors have emerged as promising alternatives to overcome these limitations. In this study, we introduce a simple, portable, and cost-effective non-enzymatic electrochemical sensor based on carbon black (CB) and silver nano-particle-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 immo-bilization on the DCell working electrode. Electrochemical investigations revealed that the DCell-CB//Ag/δ-FeOOH sensor exhibited an approximately twofold higher apparent heterogene-ous electron transfer rate constant than the DCell–Ag/δ-FeOOH sensor, capitalizing on CB ad-vantages. Moreover, the sensor displayed excellent electrochemical response for H2O2 reduction, boasting a low detection limit of 22 µM and a high analytical sensitivity of 214 μA mM-1 cm-2. Notably, the DCell-CB//Ag/δ-FeOOH sensor exhibited outstanding selectivity for H2O2 detection, even in potential interferents such as dopamine, uric acid, and ascorbic acid. Furthermore, the sensor demonstrated its suitability for monitoring H2O2 in complex biological samples, as evidenced by H2O2 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 H2O2 monitoring in diverse biomedical and environmental applications.
Chemistry and Materials Science, Analytical Chemistry
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