Quantum Chemical Studies and Electrochemical Investigations of Polymerized Brilliant Blue-Modified Carbon Paste Electrode for In Vitro Sensing of Pharmaceutical Samples

Abstract

To develop an electrochemical sensor for electroactive molecules, the choice and prediction of redox reactive sites of the modifier play a critical role in establishing the sensing mediating mechanism. Therefore, to understand the mediating mechanism of the modifier, we used advanced density functional theory (DFT)-based quantum chemical modeling. A carbon paste electrode (CPE) was modified with electropolymerization of brilliant blue, later employed for the detection of paracetamol (PA) and folic acid (FA). PA is an analgesic, anti-inflammatory and antipyretic prescription commonly used in medical fields, and overdose or prolonged use may harm the liver and kidney. The deficiency of FA associated with neural tube defects (NTDs) and therefore the quantification of FA are very essential to prevent the problems associated with congenital deformities of the spinal column, skull and brain of the fetus in pregnant women. Hence, an electrochemical sensor based on a polymerized brilliant blue-modified carbon paste working electrode (BRB/CPE) was fabricated for the quantification of PA and FA in physiological pH. The real analytical applicability of the proposed sensor was judged by employing it in analysis of a pharmaceutical sample, and good recovery results were obtained. The potential excipients do not have a significant contribution to the electro-oxidation of PA at BRB/CPE, which makes it a promising electrochemical sensing platform. The real analytical applicability of the proposed method is valid for pharmaceutical analysis in the presence of possible excipients. The prediction of redox reactive sites of the modifier by advanced quantum chemical modeling-based DFT may lay a new foundation for researchers to establish the modifier–analyte interaction mechanisms.

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

“…where s is the standard deviation of six blank measurements and m is slope of the calibration graph (Ganesh et al 2021b;Analytical Methods Committee 1987). The LOD and LOQ of FA at NC/CPE was calculated to be 0.09 µM and 0.3 µM, respectively; this was comparatively lower as compared to previous reports as given in Table 4 (Afshar et al 2020;Yuan et al 2020;Ganesh et al 2021a;Zhang et al 2016;Kumara et al 2019;Tanuja et al 2017;Narayana et al 2015;Ojani et al 2009;Garcia et al 2021).…”

“…The carbon paste was prepared by an add-mixing of finely ground graphite powder (70%) and binder (30%, silicon oil) in a mortar till a homogenous thick paste was obtained. This paste was then transferred and tightly packed into the cavity of the carbon paste electrode (CPE) and then smoothened on a piece of paper; later it was named as bare carbon paste electrode (bare/CPE) (Ganesh et al 2021a).…”

“…S3 (see supplementary information). This might be due to the over thickness of polymeric film and less exposure of carbon paste surface (Ganesh et al 2021a(Ganesh et al , 2021bGanesh et al 2021a, b,c;Chandrashekar et al 2019). Therefore, to achieve the remarkable voltammograms fifteen cyclic sweeps were considered to fabricate the NC/CPE.…”

“…However, after the modification the redox peak potentials corresponding to Fe 2+/3+ redox probe were observed at Epa = 0.2632 V and Epc = 0.1982 V, respectively, with the ΔEp = 0.0650 V. And also, the ratio of anodic peak current (Ipa) and cathodic peak current (Ipc) was found to be 1.16 (≈1.0), signifying the reversible process at NC/CPE. The electroactive surface area (EASA) of the working electrode was calculated by using the Randles-Sevcik's formulae (Ganesh et al 2021a). The effect of number of cyclic sweeps on the fabrication of NC/CPE and corresponding EASA was calculated and is given in Table S1 (see supplementary file).…”

“…Over the past few decades, electrochemical sensors have been used as an effective sensing platform for the detection of heavy metals (Ye et al 2020;Sultan et al 2019), pharmaceutical and clinical samples (Ganesh et al 2021a(Ganesh et al , 2021b, organic toxic pollutants (Ganesh et al 2021c;Gowri and John et al 2020), pesticides and herbicides (Prasad et al 2019;Demir 2019) and neurotransmitters (Setoudeh et al 2020). The carbon paste electrode (CPE) shows a promising applicability as an electrochemical sensor due to its wide potential window, low ohmic resistance, easy preparation, bulk surface modification and non-toxicity (Maleh et al 2019).…”