Electrochemical Determination of Norepinephrine by Means of Modified Glassy Carbon Electrodes with Carbon Nanotubes and Magnetic Nanoparticles of Cobalt Ferrite

Abstract

This study describes the electrochemical preparation of the electrocatalytic oxidation/reduction of noradrenaline in modified glassy carbon of cobalt ferrite nanoparticles and carbon nanotubes (GC/MWCNT/FCo98). The cobalt ferrite powder was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The optimum conditions found in an electrode composition were 4 μL of cobalt ferrite and 10 μL of carbon nanotubes in 0.1 mol L−1 PBS at pH 7.0. The electrode displays electrochemical behavior in a wide potential range (−0.4 to 1.0 V vs. Ag/AgCl), high conductivity, and electrode stability/durability in 0.1 mol L−1 PBS. Catalytic oxidation of noradrenaline was performed at the unmodified GC electrode at +0.60 V vs. Ag/AgCl and current of 0.17 μA and modified GC with cobalt ferrite nanoparticles and carbon nanotubes at +0.54 V vs. Ag/AgCl and current of 0.23 mA. With regard to the anodic peak current (Ipa) versus noradrenaline concentration by means of the amperometric method at the modified electrode, (which is linear in the 0.16 and 1.91 mmol L−1 concentration range), the concentration limit was 0.76 μmol L−1. In this way, the modified electrode GC/MWCNT/FCo98 was found to be a promising application for the determination of this neurotransmitter in the area of neuroscience.

Synthesis, Follow-Up, and Characterization of Polydopamine-like Coatings Departing from Micromolar Dopamine-o-Quinone Precursor Concentrations

“…Three of them are the conventionally accepted couples for the DA system (Scheme ), although other three couples were formed depending on the pH. From previous chromatography-based studies, one may suggest the presence of 6-hydroxydopamine (6-OHDA) and norepinephrine (NE). ,, If norepinephrine indeed forms, then it is plausible that the peak close to the AC (a and b) could be the noradrenochrome. , In this context, we decided to determine the oxidation peak position of 6-OHDA by DPV to try to assign either peak c or d. The peak position of the 6-OHDA standard corresponded to peak c in the mixture (Figures and ), leaving only peak d unidentified. 6-OHDA can be formed by DOQ hydroxylation in acidic media (pH < 6.0).…”

“…28,67,68 If norepinephrine indeed forms, then it is plausible that the peak close to the AC (a and b) could be the noradrenochrome. 69,70 In this context, we decided to determine the oxidation peak position of 6-OHDA by DPV to try to assign either peak c or d. The peak position of the 6-OHDA standard corresponded to peak c in the mixture (Figures 3 and 4), leaving only peak d unidentified. 6-OHDA can be formed by DOQ hydroxylation in acidic media (pH < 6.0).…”

Epitaxial Self-Assembly of Interfaces of 2D Metal–Organic Frameworks for Electroanalytical Detection of Neurotransmitters

“…The electrochemical properties of these probes have been well studied on a wide array of surfaces such as graphene, 83 MOFs, 53 gold, 84 and multicomponent coatings. 40 , 85 Their interaction with electrodes is highly dependent on their ionicity, the charge of the electrode, and surface functionality capable of facilitating their electrochemical transformation. 84 , 86 , 87 The oxidation and reduction of DA, DOPAC, and 5-HT involve two-electron, two-proton processes ( Figure S21 ).…”

“Nano”: An Emerging Avenue in Electrochemical Detection of Neurotransmitters

“…Similarly, a glassy carbon electrode modified with poly­(cresol red) was successfully used for NEP detection at pH 3 with a low detection limit of 0.2 μM in the presence of the potential interferent ascorbic acid. Similarly, carbon nanotubes, magnetic cobalt ferrite (FCo 98 ) nanoparticles, and graphene were also utilized for NEP quantification. Recent research reveals that there is a link between stress levels, depression, and NEP.…”