基于Sol-gel膜和多壁碳纳米管/铂纳米颗粒增效的电流型L-乳酸生物传感器

Amperometric L-lactate Biosensor Based on Sol-Gel Film and Multi-walled Carbon Nanotubes/Platinum Nanoparticles Enhancement

构建了基于多壁碳纳米管(Multi-walled carbon nanotubes,MWCNTs)和铂纳米颗粒(Pt-nano)的电流型L-乳酸生物传感器。将Sol-gel膜覆盖在L-乳酸氧化酶(L-lactate oxidase,LOD)和MWCNTs/Pt-nano修饰的电极表面。实验结果表明:传感器的最佳工作条件为:检测电压0.5V;缓冲液pH6.4;检测温度25℃。此传感器的响应时间为5s,灵敏度是6.36μA/(mmol/L)。连续检测4星期其活性仍保持90%,线性范围为0.2～2.0mmol/L,且抗干扰能力强。在实际血样的检测中,此传感器与传统的分光光度法具有很好的一致性。

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 μA/（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.