ionisensitiëlektrodit

Ion-selective electrodes, often abbreviated as ISEs, are electrochemical sensors that measure the activity of specific ions in a solution. They work by creating a potential difference across a selectively permeable membrane that interacts with the target ion. This potential difference is then measured against a stable reference electrode, and the resulting voltage is proportional to the logarithm of the ion's activity, following the Nernst equation.

The key component of an ISE is its sensing membrane, which is designed to be permeable to a particular ion while being impermeable to others. This selectivity is achieved through various materials, such as glass, crystalline solids, or organic polymers impregnated with ionophores. Different types of ISEs exist for measuring a wide range of ions, including hydrogen (pH electrodes), fluoride, chloride, sodium, potassium, and calcium.

The development of ISEs has revolutionized analytical chemistry by offering a simple, rapid, and often portable method for ion analysis. They find applications in diverse fields, including environmental monitoring, clinical diagnostics, industrial process control, and food analysis. Calibration is crucial for accurate measurements, typically performed using standard solutions of known ion concentrations. Despite their advantages, ISEs can be affected by interfering ions, temperature variations, and membrane fouling, requiring careful experimental design and maintenance.