A Non‐enzymatic Ag/δ‐FeOOH Sensor for Hydrogen Peroxide Determination using Disposable Carbon‐based Electrochemical Cells

Abstract

A non-enzymatic sensor for hydrogen peroxide (H 2 O 2) determination based on Ag/δ-FeOOH nanocomposite immobilized on an all-plastic disposable carbonbased electrochemical cell (DCell) is constructed by a rapid prototyping technique. Ag/δ-FeOOH is synthesized by a simple and reproducible method and its structural and morphological properties characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The Ag/δ-FeOOH is successfully immobilized on the DCell, as revealed by SEM images. The electrochemical investigation indicates that the Ag/δ-FeOOH/DCell has a good electrocatalytic response for the H 2 O 2 reduction, showing detection limit of 71 μmol L À 1 H 2 O 2 at a signal-tonoise ratio of 3 and analytical sensitivity of 215.4 μA mM À 1 cm À 2. Moreover, Ag/δ-FeOOH/DCell can be used to selectively detect H 2 O 2 in the presence of dopamine (DA), uric acid (UA), and ascorbic acid (AA). Finally, Ag/δ-FeOOH/DCell can be used to determine H 2 O 2 in fetal bovine serum. The achieved results indicate that the non-enzymatic Ag/δ-FeOOH/DCell is a costeffective alternative for the determination of H 2 O 2 .

A Disposable Carbon-Based Electrochemical Cell Modified with Carbon Black and Ag/δ-FeOOH for Non-Enzymatic H2O2 Electrochemical Sensing

“…The sensitivity of the method was 214 ± 2 µA mM −1 cm −2 . Our results demonstrate that the proposed electroanalytical method exhibits comparable features to those previously reported (see Table S1 [9,[33][34][35][36]).…”

“…δ-FeOOH was synthesized following a previously reported procedure [9,22]. In brief, 200 mL of 0.71 mM (NH 4 ) 2 Fe(SO 4 ) 2 •6H 2 O solution was mixed with 200 mL of 2 M NaOH solution under mechanical agitation.…”

“…Curves a and b demonstrate no significant change to H2O2 in the −1.0 to 1.0 V range for the DCell and DCell-CB sensors, respectively. Curve c, corresponding to the DCell-CB//δ-FeOOH sensor, shows an anodic current of 16 µA and a cathodic current of 19 µA at −0.15 V and −0.75 V, respectively, with H2O2 added, indicating the redox process of H2O2 on δ-FeOOH [9]. Curve d, representing the electrochemical profile of the DCell-CB//Ag/δ-FeOOH sensor in H2O2 solution, displays an anodic current of 134.0 µA and 39.4 µA at 0.08 V and −0.15 V, respectively, as well as a cathodic current of 100.0 µA and 57.0 µA at −0.3 V and −0.75 V, respectively.…”

“…Researchers have successfully designed sensors with H 2 O 2 sensing capabilities using non-enzymatic metal oxide/hydroxide materials. Recently, an all-plastic disposable carbon electrochemical cell modified with silver nanoparticles and δ-FeOOH has been developed, demonstrating an excellent electrocatalytic response for H 2 O 2 reduction, with a detection limit of 71 µM [9]. δ-FeOOH, one of the stable phases of iron oxyhydroxide, holds significant potential for various applications, including water treatment, organic pollutant degradation, solar cells, and photocatalysis [10].…”

N-Doped C Concatenates FeCo Alloys and Co Nanoparticles as a Dual-Functional Oxygen Catalyst for Long-Lasting Zinc–Air Batteries

“…52,53 The vibration occurring at 549 cm −1 was due to Co−O, manifesting the generation of Co(OH) 2 during the OER. 54 And the peaks at 2920, 1432, 1226, and 1047 cm −1 were assigned to the C� N, C�O, and C−O vibrations originating from the C substrate in FeCo AL &Co NP /NC. 55 The above observations further confirmed the partial reconstitution of the FeCo alloy during the OER, and the FeCo alloy was the main active site toward the OER.…”