Self-Assembled Ionic Liquid-Phosphomolybdic Acid/Reduced Graphene Oxide Composite Modified Electrode for Sensitive Determination of Dopamine

Abstract

© The Author(s) 2016. A novel reduced graphene oxide (RGO) coated glassy carbon electrode (IL-PMo12/RGO/GCE) modified with ionic liquid (IL, [BMIM][BF4] ) and phosphomolybdic acid (PMo12, H3PMo12O48) was fabricated via electrostatic self-assembling. The phosphomolybdic acid anionic monolayer could electrostatically adsorbed ionic liquid cations to form an organic and inorganic hybrid film on graphene sheets. The modified electrode was used for the determination of dopamine (DA) in the presence of uric acid (UA). This electrode anticipated the good electron mobility and large surface area of graphene, high ionic conductivity of ionic liquid besides the electron transfer property of phosphomolybdic acid. Optimization of the sensor's performance is presented and resulted in a better current signal. The linear range of the modified electrode was from 0.1-100 μM for determination of DA with an R-Square 0.9924 and with a detection limit of 3.3 × 10 -8 M (S/N = 3). The IL-PMo12/RGO/GCE also presented good stability and reproducibility.