Composite Polyacrylate−Poly(3,4- ethylenedioxythiophene) Membranes for Improved All-Solid-State Ion-Selective Sensors

Abstract

A novel type of self-plasticizing polyacrylate-based membrane was developed for all-solid-state ion-selective potentiometric electrodes. The membrane composition contains a conducting polymer (CP): poly(3,4-ethylenedioxythiophene) end capped with methacrylate groups, chemically grafted with the membrane during the photopolymerization step. This composition results in ion-selective membranes with the following advantages: lower electrical resistance compared to the CP-free membrane, facile ion-to-electron transduction between the membrane and the electrode support, controlled low activity of analyte ions, and high concentration of interferent ions (incorporated with the CP) within the membrane, potentially resulting in improved analytical parameters. Ca2+- and K+-selective membranes were chosen as model systems to study the effect of pretreatment and CP content on the potentiometric sensor's characteristics. For Ca2+ sensors, reproducible and stable Nernstian characteristics were obtained within the range from 0.1 to 10(-9) M CaCl2, without a time-consuming preconditioning step. For K+-selective sensors, the influence on Nernstian response range was observed for varying KCl concentrations in the conditioning solution, with the lowest detection limit found close to 10(-8) M KCl. Mass spectrometry coupled with laser ablation studies of the membranes revealed that in this case the detection limit is not related to primary ion content in the membrane contacting a sample solution, but is affected by interfering ion concentration close to the membrane surface.

Embedded capacitor applications of graphene oxide reinforced poly(3,4-ethylenedioxythiophene)-tetramethacrylate (PEDOT-TMA) composites

“…This makes chain length shorter resulting in an increase in its solubility in organic solvents as compared to PEDOT. PEDOT-TMA has been used in various applications such as in ion-selective membranes, hole transport layers in OLEDs, dye-sensitized organic solar cells, organic photovoltaic devices, antistatic layers, capacitors, conducting inks for printed applications and as a glucose sensor [12][13][14][15][16][17][18].…”

An All-solid-state Cd2+-selective electrode with a low detection limit

“…However, the potential instability and irreproducibility of such coated-wire electrodes (CWEs) may arise as consequence of poor ion-to-electron transduction between the ionically conducting ion-selective membrane and the electronic conductor, and water layer formed at the interface. These problems have been solved by introducing a variety of intermediate solid contacts, such as conducting polymers [11][12][13][14], redox-active selfassembled monolayers (SAMs) [15,16], or carbon nanotubes [17]. Through continuous efforts, state-of-the-art ASS-ISEs have reached performances comparable or superior to those of electrodes with internal filling solutions.…”

A New Simple Method for the Preparation of Calcium Ion Selective Electrode and its Analytical Applications

“…The analysis technology of ISE is based on the relationship between electrode potential and ion activity so as to perform a detection of ions. There are several advantages such as high selectivity, high sensitivity, quick analysis, low cost, wide variety of tested ions, and little sample size in this technology 2,3 .…”