A Novel Electrochemical Sensor for Detection of Nicotine in Tobacco Products Based on Graphene Oxide Nanosheets Conjugated with (1,2-Naphthoquinone-4-Sulphonic Acid) Modified Glassy Carbon Electrode

Abstract

A simple electrochemical sensor for nicotine (NIC) detection was performed. The sensor based on a glassy carbon electrode (GCE) was modified by (1,2-naphthoquinone-4-sulphonic acid)(Nq) decorated by graphene oxide (GO) nanocomposite. The synthesized (GO) nanosheets were characterized using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), FT-IR, and UV-Visible Spectroscopy. The insertion of Nq with GO nanosheets on the surface of GCE displayed high electrocatalytic activity towards NIC compared to the bare GCE. NIC determination was performed under the optimum conditions using 0.10 M of Na2SO4 as a supporting electrolyte with pH 8.0 at a scan rate of 100 mV/s using both cyclic voltammetry (CV) and differential pulse voltammetry (DPV). This electrochemical sensor showed an excellent result for NIC detection. The oxidation peak current increased linearly with a 6.5–245 µM of NIC with R2 = 0.9999. The limit of detection was 12.7 nM. The fabricated electrode provided satisfactory stability, reproducibility, and selectivity for NIC oxidation. The reliable GO/Nq/GCE sensor was successfully applied for detecting NIC in the tobacco product and a urine sample.

A Novel Electrochemical Sensor Based on an Environmentally Friendly Synthesis of Magnetic Chitosan Nanocomposite Carbon Paste Electrode for the Determination of Diclofenac to Control Inflammation

“…For electrochemical processes involving the same number of protons and electrons, the slope of the equation was quite close to the predicted Nernstian value of 0.059 V/pH [ 42 ]. This conclusion is in accordance with Scheme 1 (probable oxidation mechanism of DIC), which was previously described.…”

“…The current signal also grew as the scan speeds increased. The derived linear relationship between I p and Ʋ 0.5 (Equation (1)) (inset Figure 7 a) shows that the DIC oxidation process is diffusion-based [ 42 ]. Additionally, charting the relationship between log I p and the log Ʋ, as shown in Figure 7 b, revealed that the diffusion nature of DIC’s oxidation process resulted in a straight line that followed Equation (2).…”

Electrochemical sensor based on a poly-murexide modified carbon paste electrode for determination of fluoroquinolone antibiotic ciprofloxacin

“…The active surface area of the two former electrodes was estimated by applying CV to the same solution at various scan rates (the insets of Fig. 4B,C) and using Randles-Sevcik's equation (Abd-Elsabour et al, 2022;Hernández et al, 2021).…”