Ion Selective Theory | 合法醫療器材資訊網

Enzymeelectrodesarebasedonthereactionofanenzymereactingwithaspecificsubstrate,andtheresultantproductofthisreaction(usuallyH+orOH-)is ...

An Ion selective electrode is a sensor which converts the activity of a specific ion (dissolved in a solution) into a voltage (potential), which can be measured by a mV or Ion meter. The voltage is theoretically dependent on the logarithm of the ion activity, as described by the Nernst Equation.

E = E0 + (2.303*RT/nF)log(A)

The sensing part of the electrode is usually made from an ion specific membrane, coupled together with a reference electrode (either separate or as a combination). There are five main types of ion selective membranes which are detailed hereunder.

Glass membrane electrodes are formed from special ionically conducting glass. By altering the composition and constituents of the glass, changes can be made to selectivity, chemical resistance, response time, and impedance. The most common glass membrane ion selective electrode is the pH electrode...