Ionic liquid functionalized graphene oxide-Au nanoparticles assembly for fabrication of electrochemical 2,4-dichlorophenol sensor

Self-assembly of graphene oxide (GO) and Au nanoparticles (AuNPs) was covalently modified by ionic liquid (IL) containing amino groups to prepare the ternary nanocomposite of IL-GO-AuNPs. UV, IR spectra, X-ray power diffraction and scanning electron microscope confirmed the successful hybridization of these three components, leading to the larger surface area and better dispersity. Then a sensitive 2,4-Dichlorophenol (2,4-DCP) sensor was established based on IL-GO-AuNPs modified glassy carbon electrode. The IL-GO-AuNPs composite gave rise to a desirable access to the electron transfer and electrocatalytic capacity toward the oxidation of 2,4-DCP. Differential pulse voltammetry was employed for the quantitative analysis of 2,4-DCP. The proposed sensor showed a wide linear range from 0.01 to 5   μM with a low detection limit of 3   nM (S/N   =   3). The developed sensor was successfully used for the determination of 2,4-DCP in water samples with satisfactory recoveries and stability. The excellent electrocatalytic performance could be attributed to the high conductivity and more active sites of IL-GO-AuNPs.