ABSTRACT
An electrochemical L-lactate biosensor was fabricated by combining Platinum nanoparticles (Pt-nano) with multi-walled carbon nanotubes(MWCNTs).L-lactate oxidase(LOD) was immobilized on the surface of the glassy carbon electrode (GCE) modified with MWCNTs and Pt-nano.The surface of resulting LOD/MWCNTs/Pt-nano electrode was covered by a thin layer of sol-gel to avoid the loss of LOD and to improve the anti-interference ability.The cyclic voltammetric results indicated that MWCNTs/Pt-nano catalyst displayed a higher performance than MWCNTs.Under the optimized conditions, i.e., applied potential of 0.5 V, pH 6.4, 25 ℃, the proposed biosensor's determination range was 0.2-2.0 mmol/L, response time was within 5 s, and the sensitivity was 6.36 (A/(mmol/L).It still kept 90% activity after 4 weeks.The fabricated biosensor had practically good selectivity against interferences.The results for whole blood samples analyzed by the present biosensor showed a good agreement with those analyzed by spectrophotometric method.