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...

New, simple and convenient potentiometric and spectrophotometric methods are described for the determination of dextromethorphan hydrobromide (DXM) in pharmaceutical preparations. The potentiometric technique is based on developing a potentiometric sensor incorporating the dextromethorphan tetrakis(p-chlorophenyl)borate ion-pair complex as an electroactive species in a plasticized PVC matrix me...

An improved protamine-sensitive electrode based on a polymeric membrane doped with the charged ion exchanger dinonylnaphthalenesulfonate (DNNS) is used for monitoring heparin concentrations in whole blood. The electrode exhibits significant nonequilibrium potentiometric response to polycationic protamine over the concentration range of 0.5-20 mg/L in undiluted whole-blood samples. The sensor ca...

NEW, RAPID, SENSITIVE, AND ACCURATE method for determination of chloride was recently developed and described (1) which eliminates many difficulties inhereiit in other procedures. This method, called the precision null-point potentiometric method, can be applied for accurate determinations of chloride over a wide concentration range, as low as 10 M. and as high as necessary if the sample can be...

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....