Positively charged gold nanoparticles (AuNPs) were self-assembled onto the surfaces of 1-allyl-3-methylimidazolium chloride (AMIM-Cl) functionalized reduced graphene oxide sheets (RGO) here. The AMIM-Cl functionalized RGO (ILRGO) loaded with AuNPs (ILRGO@AuNPs) modified glass carbon electrodes (GCEs) possess larger effective specific surface areas which can favor the adsorption of more Sudan! into the working electrode. So the ILRGO@AuNPs composites were successfully used for the fabrication of a facile and sensitive sensor for the determination of Sudan I. And the prepared sensor exhibits a broad linear range for Sudan! spanned 4 orders of magnitude from 1.0 x 10(-1) to 1.0 x 10(-6)M and a detection limit as low as 5.0 x 10(-11) M (S/N = 3). It is expected that this green sensor can be applied in the determination of other similar dyes. (C) 2015 Elsevier B.V. All rights reserved.