Investigation of Protein Binding With All Solid‐State Ion‐Selective Electrodes

Abstract

A potentiometric sensor for studying charge based adsorption of proteins was created using a single‐piece polyaniline‐PVC ion‐selective electrode (ISE). Three different ISEs, two for Na+ and one for Cl− ion determination, were studied. The Na+‐ISEs consisted of a neutral calixarene‐based ionophore and one with a charged carrier dinonylnapthalenesulfonic acid (DNNSA) whereas for the Cl− ISE, an anion exchanger tridodecylmethylammonium chloride (TDDMA+Cl−), was used. The Na+ ISE with DNNSA as the charged carrier was successfully able to discriminate the binding of two different proteins (bovine serum albumin and lysozyme) based on their intrinsic charge.

Solid‐Contact Potentiometric Sensor Based on Polyaniline and Unsubstituted Pillar[5]Arene

“…However, no information on the implementation of pillar [5]arene in the assembly of solid-contact sensors and their compatibility with PANI is available. The redox activity of pillar [5]arene and its ability to supramolecular binding can improve the electrochemical characteristics of appropriate sensors and extend the number of potential analytes determined.…”

“…Pillararenes show complexation properties toward various cationic species (paraquat [19], Na + and K + ions [20] which can be modified by introduction of various substituents at hydroxyl groups of the macrocycle. Pillar [5]arene can be reversibly oxidized by PANI similarly to hydroquinone [21] and hence it can participate in the PANI electron exchange reactions followed by potential shift.…”

“…The redox activity of pillar [5]arene and its ability to supramolecular binding can improve the electrochemical characteristics of appropriate sensors and extend the number of potential analytes determined.…”

“…Besides oxides and complexes of transient metals, conducting polymers are intensively applied in solid-contact potentiometric devices. PANI, polypyrrole and polythiophene derivatives are described in the assembly of the solid-contact sensors for the detection of alkali and alkali-earth metals [2][3][4][5], transient metals [6][7][8][9], inorganic anions [10,11] and charged organic species [12].…”

“…Pillar [5]arene (Scheme 1) is a representative of a new class of macrocyclic molecules that is made up of hydro-quinone units linked with methylene bridges at para position [18]. Pillararenes show complexation properties toward various cationic species (paraquat [19], Na + and K + ions [20] which can be modified by introduction of various substituents at hydroxyl groups of the macrocycle.…”