A new amperometric ß-ODAP biosensor

Introduction The Lathyrus/lathyrism challenge is broad-based by its nature and requires multi-disciplinary efforts of specialists in the field of epidemiology, neurology, biochemistry, chemistry, nutrition, and agronomy. The role of chemists is in systematic determination of minor natural products in L. sativus seeds so that the sole responsibility of ß-ODAP for neurolathyrism is ascertained . Moreover, analytical chemists play a pivotal role in the development of a simple and reliable analytical method for ß-ODAP quantitation in seeds, food preparations, and biological samples taken from victims since lack of such a method hindered, in one way or another, research undertakings in the aforementioned disciplines. Our work addresses the latter role of targeting the development of an amperometric biosensor for ß-ODAP. This ß-ODAP biosensor is based on the pioneering work of Moges and Johannson that reported the activity of glutamate oxidase (GlOD) towards ß-ODAP . One of the oxidation products, hydrogen peroxide, reduces the tetravalent manganese (modifier in the screen printed carbon electrode, SPCE) to lower oxidation states that reoxidize again electrochemically producing a current proportional to the concentration of ß-ODAP. Material and Methods MnO2 bulk-modified SPCEs were produced in accordance to previous reports and the flow system and the electrochemical analyzer used were basically the same . GlOD was immobilized by entrapment in neutralized Nafion film as effected by drop coating the enzyme-polymer mixture onto the surface of the SPCE.