We report for the first time on in situ transduction of electrochemical responses of ion-selective electrodes, operating under non-zero-current conditions, to emission change signals. The proposed novel-type PVC-based membrane comprises a dispersed redox and emission active ion-to-electron transducer. The electrochemical trigger applied induces a redox process of the transducer, inducing ion exchange between the membrane and the solution, resulting also in change of its emission spectrum. It is shown that electrochemical signals recorded for ion-selective electrodes operating under voltammetric/coulometric conditions correlate with emission intensity changes recorded in the same experiments. Moreover, the proposed optical readout offers extended linear response range compared to electrical signals recorded in voltammetric or coulometric mode.

No abstract

No abstract

A new concept of easy to make, potentially disposable potentiometric sensors is presented. A thermoprocessable carbon black-loaded, electronically conducting, polylactide polymer composite was used to prepare substrate electrodes of user’s defined shape/arrangement applying a 3D pen in a hot melt process. Covering of the carbon black-loaded polylactide 3D-drawn substrate electrode with a PVC-based ion-selective membrane cocktail results in spontaneous formation of a zip-lock structure with a large contact area. Thus, obtained ion-selective electrodes offer sensors of excellent performance, including potential stability expressed by SD of the mean value of potential recorded equal to ±1.0 mV (n = 6) within one day and ±1.5 mV (n = 6) between five days. The approach offers also high device-to-device potential reproducibility: SD of mean value of E 0 equal to ±1.5 mV (n = 5).

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.