A novel electrochemical sensor for estradiol based on nanoporous polymeric film bearing poly{1-butyl-3-[3-(N-pyrrole)propyl]imidazole dodecyl sulfonate} moiety

•Electrochemical fabrication of a novel ionic liquid based polymeric film electrode.•Studies on voltammetric behaviors of estradiol at the polymeric film electrode.•Effective oxidation peak current for the voltammetric determination of estradiol.•Application of the polymeric film electrode for estradiol assay in real sample.

Using 1-butyl-3-[3-(N-pyrrole)propyl]imidazolium tetrafluoroborate ionic liquid as functional monomer, a nanoporous polymeric film modified glassy carbon electrode was fabricated with potential step from 0 V to 1.2 V. Followed by anionic exchanging, a hydrophobic electrochemical interface bearing poly{1-butyl-3-[3-(N-pyrrole)propyl]imidazolium dodecyl sulfonate} moiety was achieved. The obtained nanoporous polymeric hydrophobic film modified glassy carbon electrode, which denoted as BPIDS/GCE, was characterized with scanning electron microscopy and electrochemical impedance spectrum. Voltammetric behavior of estradiol at the BPIDS/GCE was investigated, and an irreversible oxidation peak was observed in the potential range from −0.2 V to 1.0 V. In comparison with the unmodified electrode, slightly positive shift of peak potential and dramatic increasing of peak current were observed obviously at the BPIDS/GCE. Experimental conditions for estradiol determination were optimized. Under optimal conditions, the oxidation peak current was linearly related to estradiol concentration in the range of 1.0 × 10−7–1.0 × 10−5 mol L−1. The detection limit was estimated to be 5.0 × 10−8 mol L−1 (S/N = 3). The recoveries for the determination of estradiol in human serum samples demonstrated that an accurate method has been developed.

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