An electrochemically exfoliated graphene/poly(3,4-ethylenedioxythiophene) nanocomposite-based electrochemical sensor for the detection of nicotine

• Published in: Materials advances Vol. 2; no. 1; pp. 3336 - 3345
• Main Authors: Rajendran, Jerome, Reshetilov, Anatoly N, Sundramoorthy, Ashok K
• Format: Journal Article
• Language: English
• Published: 24.05.2021
• ISSN: 2633-5409; 2633-5409
• DOI: 10.1039/d0ma00974a

A novel, simple and 'green' electrochemical exfoliation method was used to prepare a graphene (GR) dispersion. The as-obtained GR was characterized using HR-TEM, which confirmed the exfoliation of a few layers of graphene from graphite sheets. Furthermore, the GR film was coated on a glassy carbon electrode (GCE) surface via drop-casting. Then, electro-polymerization was carried out using the GR-modified electrode in acetonitrile solution (ACN) containing 10 μM 3,4-ethylenedioxythiophene (EDOT) and 100 mM lithium perchlorate (LiClO 4 ). The electro-polymerized PEDOT (poly(3,4-ethylenedioxythiophene)) on the GR film-modified electrode was analyzed using FE-SEM and Raman spectroscopy, which confirmed the successful incorporation of PEDOT on the GR surface. The electrochemical characterization of PEDOT/GR/GCE was carried out by electrochemical impedance spectroscopy (EIS) in 0.1 M KCl containing 5 mM [Fe(CN) 6 ] 3−/4− . The electrochemical measurements revealed that our proposed PEDOT/GR film exhibited a high active surface area, redox currents and high charge transfer rate ( K s ). Under optimized conditions, PEDOT/GR/GCE showed a higher oxidation peak current for nicotine at +0.91 V ( vs. Ag/AgCl) in 0.1 M phosphate buffer solution (PBS; pH 7). Furthermore, PEDOT/GR/GCE responded linearly for nicotine detection from 0.5 to 1000 μM with a limit of detection at 47 nM. The selectivity and sensitivity of the electrochemical sensor (PEDOT/GR/GCE) were determined in the presence of important interfering molecules. In addition, the stability and reproducibility of the PEDOT/GR/GCE sensor were tested. Finally, the PEDOT/GR-based sensor was successfully applied to detect nicotine in tobacco samples with high accuracy. Electro-polymerized PEDOT film on a graphene-modified electrode is demonstrated as a selective electrochemical nicotine sensor. Nicotine was detected with high selectivity and a real sample analysis was carried out.