Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7704237 | Bioelectrochemistry | 2018 | 10 Pages |
Abstract
An amperometric biosensor based on an l-lysine-α-oxidase (LO) layer immobilized by co-crosslinking onto the surface of an overoxidized polypyrrole modified Pt electrode (Pt/oPPy) and able to analyse l-lysine (Lys) in untreated human serum is described. The sensing electrode has been characterised and a proper enzyme kinetics optimisation permits to use a low specific enzyme as LO from Trichoderma viride for the selective biorecognition of Lys in the presence of other interferent amino acids; a kinetics study of LO evidenced also the allosteric behaviour of this enzyme, a kinetic feature which was never reported before for this enzyme. The biosensor showed a sensitivity of 0.11â¯Î¼A/mMâ¯mm2, linear responses up to 4â¯mM and a limit of detection of 2â¯Î¼M; the within-a-day coefficients of variation for replicate (nâ¯=â¯5) were 0.92% and 1.35% at 4â¯mM and 0.2â¯mM Lys levels, respectively. The permselective behaviour of Pt/oPPy modified electrode assured an interference- and fouling-free determination of Lys even in untreated serum samples. The determination of Lys in human serum from healthy donors gave Lys levels in good agreement with the expected values so that the use of the proposed biosensor appears promising in the relevant clinical fields.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Rosanna Ciriello, Francesca De Gennaro, Silvio Frascaro, Antonio Guerrieri,