Another advancement, known as integrated amperometry, has increased the sensitivity for other electrochemically active species, such as amines and many compounds that contain reduced sulfur groups, that are sometimes weakly detected by PAD.
[3] Further work was done in chromaffin cells to investigate catecholamine release from large dense core vesicles.
The simplest form of amperometric detection is single-potential, or direct current (DC), amperometry.
Single-potential amperometry has been used to detect weak acid anions, such as cyanide and sulfide, which are problematic by conductometric methods.
Another, possibly more important advantage of amperometry over other detection methods for these and other ions, such as iodide, sulfite, and hydrazine, is specificity.
PAD is most often used for detection of carbohydrates after an anion exchange separation, but further development of related techniques show promise for amines, reduced sulfur species, and other electroactive compounds.
In order to record vesicle fusion, a carbon fiber electrode is brought close to the cell.