Peroxide Electrochemical Sensor and Biosensor Based on Nanocomposite of TiO2 Nanoparticle/Multi-Walled Carbon Nanotube Modified Glassy Carbon Electrode

Abstract

A hydrogen peroxide (H2O2) sensor and biosensor based on modified multi-walled carbon nanotubes (CNTs) with titanium dioxide (TiO2) nanostructures was designed and evaluated. The construction of the sensor was performed using a glassy carbon (GC) modified electrode with a TiO2–CNT film and Prussian blue (PB) as an electrocalatyzer. The same sensor was also employed as the basis for H2O2 biosensor construction through further modification with horseradish peroxidase (HRP) immobilized at the TiO2–fCNT film. Functionalized CNTs (fCNTs) and modified TiO2–fCNTs were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-Ray DifFraction (XRD), confirming the presence of anatase over the fCNTs. Depending on the surface charge, a solvent which optimizes the CNT dispersion was selected: dimethyl formamide (DMF) for fCNTs and sodium dodecylsulfate (SDS) for TiO2–fCNTs. Calculated values for the electron transfer rate constant (ks) were 0.027 s−1 at the PB–fCNT/GC modified electrode and 4.7 × 10−4 s−1 at the PB–TiO2/fCNT/GC electrode, suggesting that, at the PB–TiO2/fCNT/GC modified electrode, the electronic transfer was improved. According to these results, the PB–fCNT/GC electrode exhibited better Detection Limit (LD) and Quantification Limit (LQ) than the PB–TiO2/fCNT/GC electrode for H2O2. However, the PB film was very unstable at the potentials used. Therefore, the PB–TiO2/fCNT/GC modified electrode was considered the best for H2O2 detection in terms of operability. Cyclic Voltammetry (CV) behaviors of the HRP–TiO2/fCNT/GC modified electrodes before and after the chronoamperometric test for H2O2, suggest the high stability of the enzymatic electrode. In comparison with other HRP/fCNT-based electrochemical biosensors previously described in the literature, the HRP–fCNTs/GC modified electrode did not show an electroanalytical response toward H2O2.

Electrochemical Sensor Based on Prussian Blue Electrochemically Deposited at ZrO2 Doped Carbon Nanotubes Glassy Carbon Modified Electrode

“…The challenge in the literature is to produce chemically modified electrodes, at which the overvoltage, both the electrochemical H2O2 oxidation and reduction reaction can be reduced so that measurements can be performed at oxidation potentials less than +1.0 V and reduction potentials below −0.1 V (vs. SCE) [54], respectively. According to our previous results [47], the PB/fCNTs/GC electrode exhibited an unstable behavior at the potentials applied for detection H2O2. Therefore, the PB/ZrO2-fCNT/GC modified electrode was considered the best electrode for the evaluation H2O2 detection in terms of operability.…”

“…For PB/fCNTs/GE modified electrode, in the reduction zone, the I pa /I pc has an average of 0.86, which indicates an almost-complete reversibility at the electrode; while peak-to-peak separation potential (∆E p ) is +0.26 V showing a higher resistance produced by the layers. In the oxidation zone the I pa /I pc average is 1.13 and ∆E p is +0.16 V [ 47 ]. The PB/ZrO 2 -fCNTs/GC modified electrode, in the reduction zone, displays a I pa /I pc of 0.79 and the ∆E p is +0.28 V; while in the oxidation zone, displays a I pa /I pc of 1.6 and the ∆E p is +0.27 V. These results, suggest a quasi-reversible reaction processes of the PB at the modified electrode surfaces.…”

Detection of Hydroxyl Radicals Using Cerium Oxide/Graphene Oxide Composite on Prussian Blue

“…The increase of sensor conductivity is explained with an intrinsic characteristic of PB as an electrocatalyst. PB is well-known for its redox catalysis that increases a rate of electron transfer in a redox reaction between an electrode surface and electrolyte in a solution [ 52 , 53 ]. The addition of a PB layer on the electrode surface as an interlayer between the electrode and the CeNP/GO composite layer can facilitate the electron transfer resulting in an increase in the sensor conductivity [ 54 , 55 ].…”

Synthesis, Catalytic Properties and Application in Biosensorics of Nanozymes and Electronanocatalysts: A Review

“…These include different material types, such as Nafion-cytochrome c [ 85 ], supramolecular complexes of hydrogel [ 86 ], nanocomplexes of lanthanides [ 87 , 88 , 89 , 90 , 91 , 92 ], Co 3 O 4 @CeO 2 hybrid microspheres [ 93 ], transition metal oxides and their composites [ 71 , 94 , 95 , 96 , 97 , 98 , 99 ], as well as noble metals: Au [ 100 ], Fe/Au [ 101 ], Au/Pt [ 102 ], Pt [ 103 , 104 ], Ru [ 105 ], Pt/Ru [ 60 ], Pd, Pd@Pt [ 106 ], Pd/Pt [ 107 ], Pd@γ-Fe 2 O 3 [ 108 ], etc. In the last decade, special interest in bionanotechnology has focused on the use of NZs based on carbon materials such as fullerenes [ 109 ], Prussian blue [ 110 ], TiO 2 [ 111 ] or Fe 2 O 3 /Pt-modified [ 112 ] multi-walled carbon nanotubes, hemin-graphene hybrid nanosheets [ 113 ], Pt/Ru/3D graphene foam [ 114 ], graphene oxide [ 115 ], Au/Pt/Au-graphene oxide nanosheets [ 116 ], Pd-magnetic graphene nanosheets [ 117 ], hemin-graphene-Au hybrid [ 118 ], IrO 2 [ 119 ], Cu-Ag [ 120 ] or Fe 2 O 3 -modified graphene oxide [ 121 ] ( Figure 4 ), Co-modified magnetic carbon [ 122 ], Co 3 O 4 graphene composite [ 123 ], carbon nanofibers […”