Preparation and characterization of gold nanoparticle-graphene nanoribbon modified glassy carbon electrode and its electroanalytical applications of paracetamol and Sudan I

In this study, gold nanoparticle decorated graphene nanoribbons were prepared with the help of thiol brigde. After characterizing by the transmission electron microscopy (TEM) and X-ray photoelectron microscopy, the obtained nanomaterials were used for modification of to glassy carbon electrode surface (AuNP-GNR/GC). AuNP-GNR/GC electrode was characterized by Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Two different electroanalytical analysis applications were designed for AuNP-GNR / GC electrode. In the first application, an azo due Sudan I (S-I) was determined by using the differential pulse voltammetry (DPV). After optimization for S-I determination conditions, the lower limit of detection was determined as 1 nM (S/N=3) in the concentration range of 0.01-75 µM. (R2=0,9964) The accuracy and precision of the developed method were determined using intraday and inter-day. The effects of the 1000 µM Na+, K+, Mg2+, Cl−, Cd2+, Pb2+, Fe3+, Ni2+, Zn2+, Al3+ ions which are possible interferants as well as glucose, glycine, ascorbic acid, dopamine and uric acid molecules at same concentration on the oxidation peak current of 100 µM S-I were also investigated. The interference was found to be acceptable and it was in the range of -4.71% to +4.02%. As real sample tomato sauce, ketchup and hot sauce samples that supplied from the markets were analyzed using of the developed method by using standard adding method. The recoveries of spiked samples were between 95.3% and 104%. In an another application with the same modified electrode, determination of paracetamol (Pct) were performed using DPV. After determining the optimum conditions of the analysis, in the 0.1-3.0 µM concentration range (R2 = 0.9964), the lower limit of detection were 5 nM (S / N = 3). After the investigation of the accuracy and precision of the developed method; glucose, caffeine, ascorbic acid, dopamine, citric acid and urea which are possible interferants for assay, effect on the 1 µM Pct determination using DPV were investigated. The recoveries of Pct in various pharmaceutical, tea and tap water samples were ranged from 96.3% to 101.5%.