Teresa Blaz

Conducting polymer-based ion-selective electrodes

Single-piece, conducting polymer-based, potentiometric sensors with enhanced cationic sensitivity were obtained by doping a polypyrrole with metal-complexing, multivalent anions. Sulphosalycilic acid, Tiron, Eriochrome Black T and Kalces have been used as doping ions. Predominant sensitivity for copper was observed for the first two dopants, whereas for the two remaining ones, induced response for magnesium and calcium was found, respectively. Interestingly, in all sensors studied the metal-binding properties of the specific ligands known from polar solvents were retained. Hence, the specific reagents can be deliberately utilized for the construction of conducting polymer-based ion-selective sensors.

Electrochemical deposition and properties of polypyrrole films doped with calcion ligands

The properties of polypyrrole (PPy) film doped with calcion (calcichrome) in the process of electrochemical polymerization from aqueous solutions are presented. The properties of the films were inspected using different electrochemical methods, analysis by energy dispersive X-ray analysis and X-ray diffraction. Since the calcion ligands introduced to the PPy film retain the metal-complexing properties known from the aqueous solutions, it is possible to design calcium-sensitive sensors with an anticipated open-circuit response.

All-Solid-State Reference Electrode with Heterogeneous Membrane

Novel reference electrodes with a solid contact coated by a heterogeneous polymer membrane are described. The electrodes are obtained using Ag nanoparticles, AgBr, KBr suspended in tetrahydrofuran solution of PVC and DOS and deposited on Ag substrate, or another substrate covered with Ag, by drop casting. After a short period of soaking in a KBr solution, stable and reproducible formal potentials of -157 ± 2 mV (vs Ag/AgCl/3 M KCl) were observed, and the solid-contact reference electrodes were ready to use. It is shown that the described reference electrodes are relatively insensitive to the changes in the sample matrix, the concentrations of ions, the pH and the redox potential. These electrodes can also be fabricated in miniaturized form, and thus used to produce miniaturized multielectrode probes.