What type of reaction takes place in ion selective electrodes?
Such an electrode has a “double reaction” mechanism – an enzyme reacts with a specific substance, and the product of this reaction (usually H+ or OH−) is detected by a true ion-selective electrode, such as a pH-selective electrodes.
What is an ion-selective electrode used for?
Ion-selective electrodes (ISEs) are very similar in use to pH electrodes. They are used for chloride, potassium, calcium, carbon dioxide/carbonate, oxygen, and a variety of other ions. These methods are particularly suited for field analysis and online measurements.
Which electrode responds to exclusively to one kind of ion?
Ion-selective electrodes
Ion-selective electrodes (ISEs) are electroanalytical sensors whose signals depend on the activities of ions in solution and exhibit a certain degree of selectivity for particular ionic species. The operation of classical ISEs is based on direct measurement of a single membrane potential at zero net current.
What are the characteristics of ion selective electrodes?
Explanation: Ion selective electrodes have wide concentration range. It is highly selective to a particular ion. 8. Ion selective electrode are unaffected by colour or turbidity of the solution.
What is Nernstian response?
Nernstian response : An electrode is said to have a Nernstian response over a given concentration range if a plot of the potential difference (when measured against a reference electrode) versus the logarithm of the ionic activity of a given species in the test solution, is linear with a slope factor which is given by …
What is selectivity coefficient in ion-selective electrode?
The selectivity coefficient is a numerical measure of how well the membrane can discriminate against the interfering ion. To put this in perspective, if an electrode has equivalent responses to the two ions, then kij = 1.0.
Which of these is not ion selective electrode?
Clarification: Thermistors are used in calorimetric biosensor to measure the heat generated during the reaction. Hence it is not an ion-selective electrode. Glass electrodes, glass pH electrodes and solid-state electrodes are types ion-selective electrodes that are used in the potentiometric biosensor. 5.
What is meant by Nernstian behavior in an indicator electrode?
STUDY. Only $35.99/year. What is meant by nernstian behavior of an indicator electrode? If an indicator exhibits nernstian behavior, it follows the Nernst equation with its potential changing by 0.059/n V per ten-fold change in concentration.
What is a Nernstian slope?
The term 2.3(RT/nF) is referred to as the Nernst slope. For an ideal electrode, the slope at 25°C is 59.16 mV per charge for an ion with a valence of 1. For an ion with a valence of 2, the slope would be 29.58 mV. The slope (S) is also an indicator of ISE performance.
Is pH electrode is an ion-selective electrode?
The most well-known and highly used ion-selective electrode is a pH electrode, which is sensitive toward the H+ ion. Using pH electrodes as an example, after appropriate calibration, it is quite trivial to measure the pH of a solution.