Electrosensing Platform for Varenicline Based on Reduced Graphene Oxide

Abstract

Graphene oxide (GO) was synthesized and reduced by chemical, hydrothermal and electrochemical methods. The GO and reduced GO was characterized by XRD, FTIR, absorption, Raman, FESEM and AFM methods. Chemically reduced GO (CrGO) was observed to efficiently enhance the electron transfer kinetics of varenicline compared to hydrothermally and electrochemically reduced GO. Hence, CrGO was used for the fabrication of an electrochemical sensor for the determination of varenicline in the concentration range of 0.03–50 µM with a limit of detection of 7.03 nM. The applicability of the proposed sensor was demonstrated by analyzing the biological samples containing varenicline.

Electrosensing of an alpha-adrenergic agonist psychoactive methyldopa using a sodium bentonite–graphene oxide nanocomposite

“…1D). The D band at ~1305 cm -1 indicated the existence of defective structures in a single-crystal graphene layer and the G band at ~1594 cm -1 represented the E 2g zone center mode of the crystalline graphite [34]. Further, the relative intensity ratio of D to G bands (ID/IG ratio) reflected the defect density in graphene 50 sheets [34].…”

Electrochemical Investigations of Biomolecules Using Carbon Nanotube and Graphene Based Modified Electrodes

“…The material, rGO has numerous unexpected properties where electrons obey a linear dispersion relation and behave like massless relativistic particles, resulting in the observation of a number of very peculiar electronic properties such as the quantum Hall effect and transport via relativistic Dirac fermions [22,23]. Their unusual electronic and robust transport properties may be useful in the electronics or in the related applications [25]. As an example, Seetharamappa and co-workers have fabricated the rGO modified glassy carbon electrode, rGO prepared through different reduction approaches ( Figure 5) [i.e.…”

“…As an example, Seetharamappa and co-workers have fabricated the rGO modified glassy carbon electrode, rGO prepared through different reduction approaches ( Figure 5) [i.e. chemical (Figure 5B), electrochemical and hydrothermal ( Figure 5C) [25]. These were used to investigate the electrochemistry of smoking cession drug, varenicline(VAR) and further utilized to develop an alternative electroanalytical methods for its determinations in biological fluids [25].…”

“…chemical (Figure 5B), electrochemical and hydrothermal ( Figure 5C) [25]. These were used to investigate the electrochemistry of smoking cession drug, varenicline(VAR) and further utilized to develop an alternative electroanalytical methods for its determinations in biological fluids [25]. In the system, VAR exhibited increased electrochemical response at CrGO/GCE when compared to that at HrGO and ErGO modified electrodes ( Figure 5C).…”

“…The porous morphology makes CrGO ( Figure 5B) to expose more of its electrochemical active sites to VAR. Hence, the electrode, CrGO/GCE was utilized to develop electroanalytical method for the sensitive determination of VAR with detection limit of 7.03 nM [25]. The same research group also exploited the use of ErGO modified GCE for sensing of various drug molecules in pharmaceutical formulations [26][27][28].…”