Magnetic nanoparticles and ionic liquid effect on electrochemical sensor performance

Magnetic nanoparticles and ionic liquid (IL, 1-hexyl-3-methyl-imidazolium bromide) based on graphene oxide (GO) composite provide unique physical and chemical properties in electrochemical sensor performance. Magnetic nanoparticles can cover active sites that increase chemical reactions with easy separation. IL increases the rate of electron transfer between the modified electrode and solution because it includes conductive adhesion properties. Also, IL in the next steps of design carbon paste electrodes (CPE) increases the cohesion. This study aims to investigate the effects of magnetic nanoparticles and IL on the electrochemical detection of dopamine (DA). DA has a vital role in the mammalian central nervous system and a change in its value from the standard range leads to a broad array of mental diseases. However, magnetic graphene oxide (MGO) may not be capable of enhancing electrochemical signs alone. In this regard, after the synthesis of MGO, IL was established on a composite. Then gold nanoparticles (AuNPs) and molecularly imprinted polymers (MIP) were modified into a MGO nanocomposite. MIP polymerization was continued by methacrylic acid (MAA) in the presence of DA as a template molecule. The developed sensor with modified nanocomposite was studied with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The modified sensor based on nanocomposite with a broad concentration linear range, between 1x10(-7) to 1x10(-4) mol L-1 and a limit of detection of 1x10(-8) mol L-1 (S/N=3) was used for the detection of DA in biological samples. Furthermore, these results prove that MGO was improved on active sites of surface nanocomposite and IL increased conductivity in the based electrochemical sensor for DA detection.