Electrochemical Detection of Ascorbic Acid in Oranges at MWCNT-AONP Nanocomposite Fabricated Electrode

Abstract

Ascorbic acid (AA) is an essential vitamin in the body, influencing collagen formation, as well as norepinephrine, folic acids, tryptophan, tyrosine, lysine, and neuronal hormone metabolism. This work reports on electrochemical detection of ascorbic acid (AA) in oranges using screen-print carbon electrodes (SPCEs) fabricated with multi-walled carbon nanotube- antimony oxide nanoparticle (MWCNT-AONP) nanocomposite. The nanocomposite-modified electrode displayed enhanced electron transfer and a better electrocatalytic reaction towards AA compared to other fabricated electrodes. The current response at the nanocomposite-modified electrode was four times bigger than the bare electrode. The sensitivity and limit of detection (LOD) at the nanocomposite modified electrode was 0.3663 [AA]/µM and 140 nM, respectively, with linearity from 0.16–0.640 μM and regression value R2 = 0.985, using square wave voltammetry (SWV) for AA detection. Two well-separated oxidation peaks were observed in a mixed system containing AA and serotonin (5-HT); and the sensitivity and LOD were 0.0224 [AA]/µA, and 5.85 µΜ, respectively, with a concentration range from 23 to 100 µM (R2 = 0.9969) for AA detection. The proposed sensor outperformed other AA sensors reported in the literature. The fabricated electrode showed great applicability with excellent recoveries ranging from 99 to 107 %, with a mean relative standard deviation (RSD) value of 3.52 % (n = 3) towards detecting AA in fresh oranges.

Comparative electrochemical properties of polyaniline/carbon quantum dots nanocomposites modified screen-printed carbon and gold electrodes

“…Also, these outcomes may be due to the high surface area and the excellent electrical conductivity of the nanomaterials and the composite, which promote faster and more efficient electron transport at the modified electrodes than the bare SPCE. Modified electrodes with lower anodic peak potential (E pa ) than bare electrodes, low ΔE p , and an I pa /I pc value close to unity support a thermodynamically feasible, fast and reversible electron transfer [50,51]. Specifically, obtaining a value of ΔE p that is lower than that of a bare electrode with a modified electrode implies that the modified electrode supports a faster electron transfer kinetics [51].…”

“On–off–on” fluorescent sensor based on Ti3C2 quantum dots and CoOOH nanosheets for the detection of ascorbic acid

“…Currently, various methods are used for the detection of AA including capillary, 4 colorimetric, 5,6 fluorescence, 7,8 and electrochemical methods. 9,10 However, the capillary method has low stability and poor repeatability, the colorimetry method does not have high sensitivity and is easily affected by background signals, and the electrochemical method is timeconsuming and unstable because of the irreversible adsorption of AA on the electrode surface. Therefore, the fluorescence method for the detection of AA has attracted increasing attention because of its low detection cost, easy operation, and high sensitivity.…”

Rapid and sensitive determination of folic acid by facile synthesized dsDNA-CuNCs fluorescent probe

“…In response to the need for FA detection, various methods have been developed, including Lactobacillus rhamnosus culture methods, colorimetric methods, electrochemical methods 1 and chromatographic methods. 2 However, the above methods have some disadvantages, such as requiring expensive and complicated instruments and complicated sample pretreatment, low sensitivity and poor selectivity.…”