Current-driven ion fluxes of polymeric membrane ion-selective electrode for potentiometric biosensing.

A polymeric membrane ion-selective electrode (ISE) for rapid potentiometric biosensing has been developed. Butyrylcholinesterase, as a target enzyme, is immobilized on the surface of the polymeric membrane. A macro-command-controlled procedure for switching between the potentiostatic and galvanostatic steps has been designed to provide a current-driven release of the butyrylcholine substrate for in situ biosensing of the enzyme and its inhibitors. This system has the flexibility of trapping substrate ions in the ISE inner filling solution and provides rapid, continuous, and reproducible measurements of enzymes and other bioanalytes involved in enzymatic systems.