Investigations On Electrochemical Sensors Based On Poly (ionic Liquid) Film For Environmental Estrogens

Poly1-[3′-(N-Pyrrolyl) propyl]-3-butylimidazolium tetrafluoroborate ionic liquid porousfilm modified glassy carbon electrode were fabricated with muti-potential step technique.Thesurface morphology, composition and electrochemical characteristics were characterized withscaning electron microscopy, x-photoelectron spectroscopy and electrochemical techniques.Electrochemical behaviors of bisphenol A and estradiol at the poly(ionic liquid) film modifiedelectrode were investigated. Experimental conditions for their determination were optimized.The proposed poly(ionic liquid) film electrodes were used to determine bisphenol A andestradiol with high sensitivity and high selectivity. The poly(ionic liquid) modified electrodewas successfully applied to analysis bisphenol A and estradiol in real samples. The resultswere consistant with that obtained by high performance liquid chromatograph. The contentsof the work were present as following:1.1-[3′-(N-pyrrole) propyl]-3-butyl imidazolium tetrafluoroborate ionic liquid wassynthezed through quaternary ammonium reaction of bromine propyl pyrrole and N-butylimidazolium bromide, followed by an anion exchange between Br-and tetrafluoroborate. Theobtained product is comformed by infrared spectrum and nuclear magnetic resonancespectroscopy.2. Poly(ionic liquid) film modified glassy carbon electrode was prepared with potential-steptechnique in an aqueous solution of1-(3’-pyrrole propyl)-3-butyl imidazole tetrafluoroborateionic liquid. The obtained film electrode was dipped into sodium dodecyl sulfonate solution toexchange anions. The morphology of the obtained poly(ionic liquid) film electrode wascharacterized with scanning electron microscopy. Nano porous structure was observed on theelectrode surface. The anion exchange between the film and sodium dodecyl sulfonatesolution was verified by x-ray photoelectron spectroscopy. The electrochemical properties ofthe film electrode was characterized by electrochemical impedance spectrum (EIS) usingFe(CN)63-/4-as electroactive probes. It was founded that the resistance of charge transfer at thefilm electrode was obviously higher than that of the bare glassy carbon electrode.Electrochemical behaviors of bisphenol A on the film electrode were investigated withvoltammetry. Compared with the bare glassy carbon electrode, the oxidation potential moveto the positive direction and the oxidation peak current significantly increased for bisphenol Aon the poly(ionic liquid) film modified electrode.Under optimal conditions, the oxidationcurrent was linearly releated to the bisphenol A concentration in the range of1.0×10-8~1.0×10-5mol/L. The proposed film electrode was used to determinebisphenol A in drinkingwater bottle. The results were consistant with that performed on high performance liquidchromatography.3. A Poly(ionic liquid) film modified electrode was prepared with potential-step technique inan aqueous solution of1-(3’-pyrrole propyl)-3-butyl imidazoledodecyl sulfonate ionic liquid. Electrochemical behaviors of estradiol on the film electrode were investigated withvoltammetry. Compared with the bare glassy carbon electrode, the oxidation potential slightlyshift towards positive potential and the oxidation peak current significantly increased at thefilm modified electrode.Under optimal conditions, the oxidation peak current was linearlyreleated to the estradiol concentration in the range of1×10-7~1×10-5mol/L.