Electrochemical Detection of H₂O₂Using an Activated Glassy Carbon Electrode

Abstract

Herein, we report the electrochemical sensing of H2O2 in milk samples using an activated glassy carbon electrode (GCE). For this purpose, activation of GCE was carried out in 0.1 M H2SO4 by continuous potential sweeping between -0.7 to 1.8 V for 25 cycles. The activated glassy carbon electrode (AGCE) showed a redox peak at 0.1 V in the neutral medium corresponding to the quinone functional groups present on the electrode surface. The AGCE was studied in (pH 7.4) 0.1 M PBS for the electro-catalysis of H2O2. The surface of the activated electrode was analyzed by Raman spectroscopy and contact angle measurements. In addition, for the activated surface, the contact angle was found to be 85º which indicated the hydrophilic nature of the surface. The different optimization parameters such as effect of electrolyte ions, electrooxidation cycles, and oxidation potential windows were studied to improve the activation process. Finally, AGCE was used to detect H2O2 from 0.1 to 10 mM and the limit of detection was found to be 0.053 mM with a linear correlation coefficient of 0.9633. The selectivity of the sensor towards H2O2 was carried out in the presence of other interferents.

Fabrication of High‐Performance MgCoO2/PEDOT:PSS@Nickel Foam Anode for Bioelectricity Generation by Microbial Fuel Cells

“…In general, charge transfer resistance (R ct ) of the working electrode is related to the diameter of semicircle which can indicate the interfacial processes of charge transport between the electrode surface and electrolyte ions [38]. In the study, EIS plots are represented by straight lines at lower frequency range whereas semicircles at higher frequency range [39]. The semicircle is formed due to charge transfer and capacitive resistance, while straight line indicates the diffusion resistance characterized by Warburg mass transfer resistance [40].…”

Graphene Nanoribbons/Manganese Oxide Nanocomposite Modified Electrode for Detection of Antimicrobial Drug Nitrofurantoin

“…Furthermore, GNR showed a broad redox peak centered at 0.125 V (E pa ∼ 0.2 and E pc ∼ 0.05 V). This redox peak was observed due to the presence of quinone functional groups on the surface of GNR which was generated during the unzipping process [41,42]. Figure 5(c) (black curve i) showed a notable redox peak at 0.8 V (E pc ∼ 0.65 and E pa ∼ 0.95 V) with high peak currents which were assigned to MnO 2 [43].…”

Electrochemical Detection of H2O2 on Graphene Nanoribbons/Cobalt Oxide Nanorods‐Modified Electrode

“…The anodic peak currents of GNR/Co 3 O 4 /GCE were increased linearly with the increase of the scanning rate from 10 to 200 mV/ s. The linear equation was established between H 2 O 2 oxidation peak currents and square root of scan rates with a correlation coefficient of (R 2 ) 0.9893 (Figure 4(b)). It was found that H 2 O 2 oxidation on GNR/Co 3 O 4 /GCE was a diffusioncontrolled process [18].…”

“…Colorimetry and fluorimetry methods are considered to be expensive and may not be suitable for general laboratory use. Electrochemical sensing of H 2 O 2 can be performed by enzymatic and nonenzymatic methods [18,19]. Enzymatic electrochemical sensors are vulnerable to the environmental factors such as temperature, pressure, pH, and biological pathogens [20].…”