Materials Research Express (Jan 2021)
Electrochemical detection of choline at f-MWCNT/Fe3O4 nanocomposite modified glassy carbon electrode
Abstract
Choline is employed as cholinergic activity marker in brain tissue in the field of clinical detection of diseases. Although, chromatographic methods and biosensors are the most commonly used techniques for choline detection, there is also an interest in exploring the efficacy of a cost effective non-enzyme based sensor for choline detection. Here, electrochemical sensors based on green synthesized metal oxides (iron (III) oxide nanoparticles) from Callistemon viminalis leaves and flowers extract (Fe _3 O _4 NPL and Fe _3 O _4 NPF) in combination of functionalized multi-walled carbon nanotube (f-MWCNT) supported on glassy carbon electrodes (GCE/f-MWCNT/Fe _3 O _4 NPL and GCE/f-MWCNT/Fe _3 O _4 NPF) were fabricated for choline detection. Morphological, structural and optical analysis of the nanocomposites were studied using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and ultra violet-visible (UV–vis) spectroscopy accordingly. In contrast, electron transport properties on bare glassy carbon electrode (GCE) and nanocomposite modified electrodes (GCE/f-MWCNT/Fe _3 O _4 NPL and GCE/f-MWCNT/Fe _3 O _4 NPF) was examined through electrochemical characterization using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Electrochemical oxidation of choline was also studied through CV, EIS, square wave voltammetry (SWV) and chronoamperometry (CA). The result proved that f-MWCNT enhanced the reactivity of Fe _3 O _4 NP towards choline oxidation with voltammetric limit of detection (0.83 and 0.36 μ M) for choline at GCE/f-MWCNT/Fe _3 O _4 NPL and GCE/f-MWCNT/Fe _3 O _4 NPF electrodes respectively. Designed sensors proved selective, reproducible, stable and applicable for real sample sensing in choline dietary supplements.
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