Structural and electrochemical characterization of carbon ion beam irradiated reduced graphene oxide and its application in voltammetric determination of norepinephrine

Abstract

Irradiation of reduced graphene oxide (rGO) sheets using 50 MeV C 4+ ion beam has been implemented to create disorders. The changes in the charge transfer resistance (R CT ) and structural variations in rGO upon irradiation have been studied using electrochemical impedance spectroscopy (EIS), Raman spectroscopy and field emission scanning electron microscopy (FE-SEM). Irradiation of rGO with 50 MeV C 4+ ion beam resulted in three fold decreased charge transfer resistance (R CT 32.91 Ω) in comparison to 93.42 Ω corresponding to pristine rGO. Electrochemical properties of irradiated rGO have been further investigated by developing an irradiated rGO modified glassy carbon electrode (GCE) for the analysis of norepinephrine (NE). Voltammetric experiments showed that irradiated rGO modified GCE (Irradiated rGO/GCE) exhibited superior response towards NE oxidation in comparison to both the pristine rGO/GCE and bare GCE. Thus, NE has been quantified using Irradiated rGO/GCE in a linear concentration range of 1 -200 µM with a detection limit of 50 nM.Detection sensitivities corresponding to bare, pristine rGO and irradiated rGO modified GCE were 0.0173, 0.1335 and 0.769 µA µM -1 respectively, demonstrating substantial improvement in sensing and electrocatalytic behaviour of rGO on exposure to ion beam. To ensure the analytical applicability of the fabricated sensor it has been successfully applied for the estimation of norepinephrine (NE) in injection, human urine and serum samples and recovery >93 % with R.S.D < 3.5 % were achieved.

Review—Progress on Carbon-Based Electrochemical Sensors for Epinephrine and Norepinephrine

“…A detection limit of 50 nM with a linear concentration range of 1-200 μM was obtained with the modified electrode. 117 Solution based chemical route was developed for synthesizing chevron like graphene nano ribbons, which was used as an EP sensor by applying the surface of GCE. Inorder to minimize interferences they selected the reduction peak corresponding to epinephrinechrome-leucoepinephrinechrome transition as analytical signal instead of the oxidation peak.…”