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 0.11 μA/mM mm², linear responses up to 4 mM and a limit of detection of 2 μM; the within-a-day coefficients of variation for replicate (n = 5) were 0.92% and 1.35% at 4 mM and 0.2 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.

一种基于l-赖氨酸-α-氧化酶（LO）层的安培生物传感器，该层通过共交联到过氧化的聚吡咯修饰的Pt电极（Pt / oPPy）的表面而固定，并能够分析未经治疗的人的l-赖氨酸（Lys）描述了血清。已经对传感电极进行了表征，适当的酶动力学优化使得可以使用低特异性酶作为木霉木霉的LO ，在存在其他干扰氨基酸的情况下对Lys进行选择性生物识别。LO的动力学研究也证明了该酶的变构行为，该酶的动力学特征以前从未报道过。生物传感器的灵敏度为0.11μA/ mM mm ²线性响应高达4 mM，检出限为2μM； 在4 mM和0.2 mM Lys水平下，复制（n = 5）的一天内变异系数分别为0.92％和1.35％。Pt / oPPy修饰电极的选择性渗透行为确保即使在未经处理的血清样品中，Lys的干扰也不会结垢。对来自健康供体的人血清中Lys的测定表明，Lys水平与预期值高度吻合，因此在相关的临床领域中，使用拟议的生物传感器显得很有希望。