Application of nanosized gold and graphene modified carbon ionic liquid electrode for the sensitive electrochemical determination of folic acid

In this study a new electrochemical folic acid (FA) sensor was proposed by using gold nanoparticles (AuNPs) and graphene (GR) modified carbon ionic liquid electrode (CILE) as the working electrode . GR and AuNPs were directly electroreduced on the surface of CILE to get the modified electrode , which exhibited excellent electrochemical performances due to the specific characteristics including higher conductivity and larger surface area . The modified electrode showed excellent electrocatalytic ability to the oxidation of FA with an irreversible oxidation peak appeared at +   1.05   V (vs. SCE) in pH   5.5 phosphate buffer solution . Electrochemical behaviors of FA on the modified electrode were carefully investigated with the electrochemical parameters calculated. Under the optimal conditions and by using differential pulse voltammetry , the oxidation peak currents were linear to FA concentration in the range from 0.01   μmol   L −   1 to 50.0   μmol   L −   1 with the detection limit as 2.7   nmol   L −   1 (3σ). The proposed method was successfully applied to the FA tablet sample determination with satisfactory results.