An Electrochemical Approach to Quantification of Volatile Organic Solvents Dispersed in Solution – Towards Bipolar Electrode Sensors

Abstract

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.

Benefits of increasing surface to volume ratio for improving electrochemical performance of poly(3‐hexylthiophene): Electrospun fibers vs. films

“…The high emission intensity observed for as prepared films, also under condition of confocal microscopy, Figure 1C, confirms that the polymer in nanofibers is in semiconducting (ion‐free), optically active form. The emission spectra of fibers mat and films obtained were similar to that of rraP3HT in solution [25] (however the maximum was shifted towards higher wavelengths compared to rraP3HT dispersed in THF, results not shown). In the case of films, the observed emission pattern is typically interpreted as a sign of disordered structure of rraP3HT chains in solid state form [26].…”

Low-Cost ZnO Spray-Coated Optical Fiber Sensor for Detecting VOC Biomarkers of Diabetes

“…Therefore, the recent development of low-cost, efficient, and high-sensitivity sensors that can operate at room temperature (RT) with different humidity levels is necessary. Many researchers have reported a new development of VOC biomarker sensors, such as electrochemical [ 22 , 23 ], resistive [ 24 , 25 ], and optical sensors [ 26 ]. However, resistive and electrochemical sensors have limitations on selectivity and shelf life.…”

Nanofibers as optical sensors for model VOCs dispersed in aqueous phase

“…Due to the different properties of dyes employed, especially different solubility in analytes, a selectivity in obtained responses can be induced. The dissolution / deaggregation is typically followed by optical methods [11,12,13], however, it was also shown that an electrochemical approach could be used for conducting polymers applied as species being dissolved upon contact with the analyte [14]. This approach can be foreseen as a variation of systems allowing visualization of odors based on arrays of different dyes [15,16] or metal ions present in sample [17].…”