Development of a Polypyrrole Modified Gold Microelectrode for Soil Nitrate Detection

Soil nitrate is an important item in soil testing for formulated fertilization. Conventional soil nitrate detection methods are reliable, but time-consuming and expensive. In this paper, a polypyrrole modified microelectrode array was developed for rapid detection of soil nitrate. The microelectrode array was fabricated using a micro-fabrication process. A thin layer of nitrate ion selective membrane was deposited onto the surface of the microelectrode array for amperometric detection by cyclic voltammetry. Simple linear regression resulted in a correlation coefficient of 0.995 between peak current of the voltammograms and nitrate concentration with a detection limit of 1times10^-4 mol/L.