Potentiometric sensors require the implementation of conducting wires for signal transduction, but this is impractical for the readout of individual nanoparticles. It is here demonstrated for the first time that the potentiometric response of ion-selective nanospheres can be observed with voltage-sensitive dyes, thereby converting nanoscale electrochemical signals into an optical readout. No re...

The possibility of using disposable plastic-carbon potentiometric sensors as enzyme biosensors was examined. Urease enzyme was immobilized on poly(vinyl chloride) based Hor NH4-selective membranes using cellulose acetate. This approach has resulted in a potentiometric response on changing the pH of the solution or NH4 ion content due to an enzymatic reaction that occurs between urease and urea....

From the analysis of the potentiometric titration data of polyelectrolytes, we can obtain the electrostatic free energy of the macromolecules. Therefore, potentiometric titration is a useful experimental procedure to study the conformation and conformational change of macromolecules. A few examples of the application of potentiometric titration to the studies on polypeptides, protein and DNA ar...

In this paper, the preparation of a potentiometric strip for pH monitoring in saliva samples is reported. The potentiometric strip consists of a solid contact pH-selective and of a solidcontact ionogel reference electrode prepared on a dual screen printed substrate. The screen printing protocols, i.e., type of inks and number of deposits, were adjusted to relatively improve the batch reproducib...

A sensitive and reliable potentiometric biosensor for determination of penicillin has been developed by exploiting the self-limiting growth of the non-conducting polymer, polytyramine. Optimum polytyramine-penicillinase (PTy-PNCnase) films for potentiometric detection of penicillin were accomplished with monomer solutions which contained 0.03 M tyramine, 37 U/mL penicillinase, 0.01 M KNO3, and ...

The preparation and potentiometric pH response properties of membranes formulated with various aminated-poly(vinyl chloride) (PVC-NH2) products are described. Products containing secondary and/or primary amino functional groups are obtained by modifying PVC with monoand/or diamines, respectively. Blank membranes prepared with either type of aminated-polymer exhibit nearly Nernstian potentiometr...

A novel potentiometric solid-state reference electrode containing single-walled carbon nanotubes as the transducer layer between a polyacrylate membrane and the conductor is reported here. Single-walled carbon nanotubes act as an efficient transducer of the constant potentiometric signal originating from the reference membrane containing the Ag/AgCl/Cl(-) ions system, and they are needed to obt...

Electrodes for scanning ion-selective potentiometric microscopy (or potentiometric SECM) were developed and used to image local concentration profiles of NH4+, K+, and Zn2' ions. Neutral carrier-based micropipet ionselective electrodes with high spatial resolution (-2-3 pm) and fast response time (-300 ms) were fabricated and employed as potentiometric SECM tips, and highresolution ion-selectiv...