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A novel approach to electrochemical determination of volatile organic compounds (VOCs) suspended in a solution is proposed. This approach benefits from properties of capacitors linked in series, where the total capacitance is affected by analyte induced changes. A tailor designed hydrophobic PVDF membrane modified with polyoctylthiophene used in this arrangement played a role of a bipolar electrode. The presence of water immiscible liquid VOCs results in spontaneous formation of a thin film on the surface of the hydrophobic polymer membrane and dissolution of modifying particulates. This effect leads to change of electrical parameters of the system: capacitance and resistance dependent on amount of VOCs present in the aqueous phase.

Nanofibers mats, prepared from poly(vinyl chloride) (PVC) containing dispersed dye Nile red (NR) were applied in a proof of concept study as optical sensors for Volatile Organic Compounds (VOCs) dispersed in an aqueous phase. Benefiting from the solubility of the dye, and in some cases, also of the polymer in model solvents belonging to the group of VOCs, an increase of emission was observed for increasing solvent concentration in the sample.The optical signal formation was observed regardless if only the dye or both dye and PVC were soluble in the tested solvent. In both cases, high sensitivity emission increases for increasing VOCs present in the aqueous phase were observed within the range of concentration of model analytes: from 200 ppm of m-xylene or from 300 ppm of styrene, to up to ca 1500 ppm. The obtained higher detection limit was lower compared to films of PVC containing the dye due to the lower availability of the material to be dissolved by analyte -solvent. The large surface area of nanofibers was useful in the detection, leading to higher signal changes compared to films.