Electrochemical investigations and theoretical studies of biocompatible niacin-modified carbon paste electrode interface for electrochemical sensing of folic acid

Abstract

The modified electrode–analyte interaction is critical in establishing the sensing mechanism and in developing an electrochemical sensor. Here, the niacin-modified carbon paste electrode (NC/CPE) was fabricated for electrochemical sensing applications. The two stable structures of the niacin were optimized and confirmed by the absence of negative vibrational frequency, at B3LYP and B3LYP-GD3BJ level and 6–311 g** basis set. The physical and quantum chemical quantities were used to explain the molecular stability and electronic structure-related properties of the niacin. The natural bond orbital (NBO) analysis was performed to disclose the donor–acceptor interactions that were a critical role in explaining the modifier–analyte interaction. The fabricated NC/CPE was used for the determination of folic acid (FA) in physiological pH by cyclic voltammetry (CV) method. The limit of detection (LOD) for FA at NC/CPE was calculated to be 0.09 µM in the linear concentration range of 5.0 µM to 45.0 µM (0.2 M PBS, pH 7.4) by CV technique. The analytical applicability of the NC/CPE was evaluated in real samples, such as fruit juice and pharmaceutical sample, and the obtained results were acceptable. The HOMO and LUMO densities are used to identify the nucleophilic and electrophilic regions of niacin. The use of density functional theory-based quantum chemical simulations to understand the sensory performance of the modifier has laid a new foundation for fabricating electrochemical sensing platforms.

Mimic uracil–uracil base pairing: self-assembly and single crystal structure

“…Gaussview 6 is used to establish the calculation model, and Gaussian 16W is used for DFT calculation. The calculation parameters of structural optimization 38–40 are as follows: #p opt freq b3lyp/6-311g(d,p) em = gd3bj. The parameters of energy calculation are: #b3lyp/6-311g(d,p) em = gd3bj.…”

Electrochemical determination of vitamin B6 in pharmaceutical and energy drink samples

“…Therefore, the electrode reaction mechanism for VB6 oxidation at poly(phenylalanine)/F-MWCNT/GCE involves two electrons and two protons. Furthermore, it is possible to determine the surface concentration of VB6 at poly (phenylalanine)/F-MWCNT/GCE from the slope of the linear plot of oxidation peak current vs. v using the following equation [52]: where  / mol cm -2 is the surface concentration of electroactive species, A / cm 2 is the electrode surface area and z, F, n, R, and T are as described in Eq. ( 4).…”

Recent Trends and Application of Nanomaterial Based on Carbon Paste Electrodes: A Short Review

“…Many research has provided another methods for preparing CPEs using carbon material. Carbon paste is frequently preparing by mixing and grinding paraffin with carbonaceous material such as graphite, carbon microspheres, and multiwall carbon nanotubes powder using mortar until the paste was obtained, then packaged or pressed into a suitable electrode body (Teflon tube) [38][39][40] . The SEM images of CPEs that produced from graphite, carbon microspheres, and MWCNTs 41) can be seen in Figure 2.…”