Abstract: In this paper, we report a new composite of reduced graphene oxide/Fe3O4-ionic liquid based molecularly imprinted polymer (RGO/Fe3O4-IL-MIP) fabricated for diphenylamine (DPA) detection. RGO/Fe3O4-IL-MIP was prepared with RGO/Fe3O4 as supporter, ionic liquid 1-vinyl-3-butylimidazolium hexafluorophosphate ([VC4mim][PF6]) as functional monomer, ionic liquid 1,4-butanediyl-3,3'-bis-l-vinylimidazolium dihexafluorophosphate ([V2C4(mim)2][(PF6)2]) as cross-linker, and diphenylamine (DPA) as template molecule. Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy, and vibrating sample magnetometer were employed to characterize the RGO/Fe3O4-IL-MIP composite. RGO/Fe3O4-IL-MIP was then drop-cast onto a glassy carbon electrode to construct an electrochemical sensor for DPA. The differential pulse voltammetry (DPV) peak current response for 20 μM DPA of RGO/Fe3O4-IL-MIP modified glassy carbon electrode (GCE) was 3.24 and 1.68 times that of RGO/Fe3O4-IL-NIP and RGO/Fe3O4-EGDMA-MIP modified GCEs, respectively, indicating the advantage of RGO/Fe3O4-IL-MIP based on ionic liquid (IL) as a cross-linker. The RGO/Fe3O4-IL-MIP sensor demonstrated good recognition for DPA. Under the optimized conditions, the RGO/Fe3O4-IL-MIP sensor exhibited a DPA detection limit of 0.05 μM (S/N = 3) with a linear range of 0.1 - 30 μM. Moreover, the new RGO/Fe3O4-IL-MIP based sensor detected DPA in real samples with satisfactory results
Template and target information: diphenylamine, DPA
Author keywords: Reduced graphene oxide, Fe3O4, molecularly imprinted polymer, ionic liquid cross-linker, Electrochemical sensor, Diphenylamine