A novel amperometric biosensor based on a co-crosslinked L-lysine-alpha-oxidase/overoxidized polypyrrole bilayer for the highly selective determination of L-lysine

作者：Guerrieri Antonio^*; Ciriello Rosanna; Cataldi Tommaso R I

来源：Analytica Chimica Acta, 2013, 795: 52-59.

DOI：10.1016/j.aca.2013.07.036

• Biosensor
• L-lysine determination
• L-lysine-alpha-oxidase
• Overoxidized polypyrrole
• Flow injection analysis
• Food analysis

An amperometric biosensor for the determination of l-lysine based on L-lysine-alpha-oxidase immobilized by co-crosslinking on a platinum electrode previously modified by an overoxidized polypyrrole film is described. The optimization of experimental parameters, such as pH and flow rate, permitted to minimize significantly substrate interferences even using a low specific, commercial enzyme. The relevant biases introduced in the measurement of lysine were just about 1% for L-arginine, L-histidine and L-ornithine, roughly 4% for L-phenylalanine and L-tyrosine. The developed approach allowed linear lysine responses from 0.02 mM up to 2 mM with a sensitivity of 41 nA/(mM x mm(2)) and a detection limit of 4 mu M (S/N = 3). No appreciable loss in lysine sensitivity was observed up to about 40 days. Allowing polypyrrole layer to remove interference from electroactive compounds, the present method revealed suitable to detect l-lysine in a pharmaceutical and cheese sample, showing a good agreement with the expected values.

• 出版日期2013-9-17