State Key Laboratory of Bioelectronics, School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
ACS Nano. 2010 Jul 27;4(7):4292-8. doi: 10.1021/nn1010057.
This study compares the electrocatalytic activity of nitrogen-doped carbon nanotubes (NCNTs) with multiwalled carbon nanotubes (MWCNTs). Results indicate that NCNTs possess a marked electrocatalytic activity toward oxygen reduction reaction (ORR) by an efficient four-electron process in the alkaline condition, while the process of MWCNTs is through a two-electron pathway. Meanwhile, NCNTs show a very attractive electrochemical performance for the redox reaction of hydrogen peroxide (H2O2) and could be employed as a H2O2 sensor at a low potential of +0.3 V. The sensitivity of the NCNT-based biosensor reaches 24.5 microA/mM, more than 87 times that of the MWCNT-based one. Moreover, NCNTs exhibit striking analytical stability and reproducibility, which enables a reliable and sensitive determination of glucose by monitoring H2O2 produced by an enzymatic reaction between glucose oxidase/glucose or choline oxidase/choline at +0.3 V without the help of the electron mediator. The NCNT-based glucose biosensor has a linear range from 2 to 140 microM with an extremely high sensitivity of 14.9 microA/mM, and the detection limit is estimated to be 1.2 microM at a signal-to-noise ratio of 3. The results indicate that the NCNTs are good nanostructured materials for potential application in biosensors.
本研究比较了氮掺杂碳纳米管（NCNTs）与多壁碳纳米管（MWCNTs）的电催化活性。结果表明，NCNTs 在碱性条件下对氧还原反应（ORR）具有显著的电催化活性，可通过高效的四电子过程进行，而 MWCNTs 的过程则是通过两电子途径。同时，NCNTs 对过氧化氢（H2O2）的氧化还原反应表现出非常有吸引力的电化学性能，可在低电位+0.3 V 下用作 H2O2 传感器。基于 NCNT 的生物传感器的灵敏度达到 24.5 μA/mM，是基于 MWCNT 的生物传感器的 87 倍以上。此外，NCNTs 表现出显著的分析稳定性和重现性，这使得通过在+0.3 V 下监测葡萄糖氧化酶/葡萄糖或胆碱氧化酶/胆碱之间的酶反应产生的 H2O2，无需电子介体即可可靠且灵敏地测定葡萄糖。基于 NCNT 的葡萄糖生物传感器的线性范围为 2 至 140 μM，灵敏度非常高，为 14.9 μA/mM，检测限估计为 3 信噪比时为 1.2 μM。结果表明，NCNTs 是用于生物传感器的潜在应用的良好纳米结构材料。
