Amperometric Detection of L-Lactate Using Nitrogen-Doped Carbon Nanotubes Modified with Lactate Oxidase
Amperometric Detection of L-Lactate Using Nitrogen-Doped Carbon Nanotubes Modified with Lactate Oxidase
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DOI：
10.1021/ac2016272
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发表时间：
2011-11-01
影响因子：
7.4
通讯作者：
Stevenson, Keith J.
中科院分区：
文献类型：
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作者：
Goran, Jacob M.;Lyon, Jennifer L.;Stevenson, Keith J.
氮掺杂碳纳米管（N-CNT）为生物传感提供了一个简单，坚固和独特的平台。它们对氧还原反应（ORR）和随后的过氧化氢（H2 O2）分解的催化活性对N-CNT表面上酶促产生的H2 O2产生了灵敏的电化学响应，消除了对额外过氧化物酶或电子转移介体的需要。玻璃碳电极用7.4原子% N-CNT、乳酸氧化酶（LOx）和四丁基溴化铵（TBABr）改性的Nafion粘合剂改性。电流型L-乳酸生物传感器的灵敏度为0.040 +/- 0.002 AM（-1）cm（-2），工作电位为-0.23 V（相对于Hg/Hg 2SO 4），200 μ M乳酸盐样品的重复性为1.6%相对标准偏差（RSD），制造重现性为5.0%（RSD），检测限为4.1 ± 1.6 μ M，线性范围为14-325 μ M。此外，在90天内，200 μ M乳酸盐样品的重复性保持在3.4%（RSD）以下。直接电子转移之间的氧化还原活性中心和N-CNTs的电活性表面覆盖率测定为0.27 nmol cm（-2）。
Nitrogen-doped carbon nanotubes (N-CNTs) provide a simple, robust, and unique platform for biosensing. Their catalytic activity toward the oxygen reduction reaction (ORR) and subsequent hydrogen peroxide (H2O2) disproportionation creates a sensitive electrochemical response to enzymatically generated H2O2 on the N-CNT surface, eliminating the need for additional peroxidases or electron-transfer mediators. Glassy carbon electrodes were modified with 7.4 atom % N-CNTs, lactate oxidase (LOx), and a tetrabutylammonium bromide (TBABr)-modified Nafion binder. The resulting amperometric L-lactate biosensors displayed a sensitivity of 0.040 +/- 0.002 AM(-1) cm(-2), a low operating potential of -0.23 V (vs Hg/Hg2SO4), a repeatability of 1.6% relative standard deviation (RSD) for 200 mu M samples of lactate, a fabrication reproducibility of 5.0% (RSD), a limit of detection of 4.1 +/- 1.6 mu M, and a linear range of 14-325 mu M. Additionally, over a 90 day period, the repeatability for 200 mu M samples of lactate remained below 3.4% (RSD). Direct electron transfer was observed between the LOx redox-active center and the N-CNTs with the electroactive surface coverage determined to be 0.27 nmol cm(-2).