Polymers (Dec 2018)

An Electrochemical Sensor for Diphenylamine Detection Based on Reduced Graphene Oxide/Fe<sub>3</sub>O<sub>4</sub>-Molecularly Imprinted Polymer with 1,4-Butanediyl-3,3′-bis-l-vinylimidazolium Dihexafluorophosphate Ionic Liquid as Cross-Linker

  • Lingyu Liu,
  • Xudong Zhu,
  • Yanbo Zeng,
  • Hailong Wang,
  • Yixia Lu,
  • Jian Zhang,
  • Zhengzhi Yin,
  • Zhidong Chen,
  • Yiwen Yang,
  • Lei Li

DOI
https://doi.org/10.3390/polym10121329
Journal volume & issue
Vol. 10, no. 12
p. 1329

Abstract

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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.

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