Investigation of protein binding with all solid-state ion-selective electrodes

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.