Modern potentiometry.

Modern Directions for Potentiometric Sensors.

This paper gives an overview of the newest developments of polymeric membrane ion-selective electrodes. A short essence of the underlying theory is given, emphasizing how the electromotive force may be used to assess binding constants of the ionophore, and how the selectivity and detection limit are related to the underlying membrane processes. The recent developments in lowering the detection ...

Ion Activity Scales for Use with Selective Ion-sensitive Electrodes

The development of a variety of selective ion-sensitive electrodes focuses attention on numerical scales for the activity of individual ionic species, for these electrodes measure the activity of the selected ion only relative to that of the same species in a reference solution of known or assigned ion activity. Nevertheless, scales of ion activity must be based on a convention from outside the...

Testing Na+ in blood

Both direct potentiometry and indirect potentiometry are currently used for Na+ testing in blood. These measurement techniques show good agreement as long as protein and lipid concentrations in blood remain normal. In severely ill patients, indirect potentiometry commonly leads to relevant errors in Na+ estimation: 25% of specimens show a disagreement between direct and indirect potentiometry, ...

Potentiometry for Study of Supramolecular Recognition Processes Between Uncharged Molecules

Scanning Tunneling Potentiometry of Semiconductor Junctions

A method for performing scanning tunneling potentiometry of semiconductor heterojunctions is described. The method yields a direct measure of the electrostatic potential distribution across the interface, with microscopic resolution. The measurement is accomplished by scanning the probe tip at constant sample-tip separation across the junction, and adjusting the sample-tip voltage to maintain a...