Analytical Sciences

Low-Potential Nicotinamide Adenine Dinucleotide Detection at a Glassy Carbon Electrode Modified with Toluidine Blue O Functionalized Multiwall Carbon Nanotubes

Jinxiang ZENG, Wanzhi WEI, Xiurong ZHAI, Jian YIN, and Ling WU

State Key Laboratory of Chemo/Biosensing and Chemometrics, Chemistry and Chemical Engineering College, Hunan University, Hunan, Changsha 410082, P. R. China

The toluidine blue O (TBO) functionalized multiwall carbon nanotubes (MWNTs) nanomaterials (TBO-MWNTs) were prepared by assembling TBO onto the surface of a MWNTs modified glassy carbon (GC) electrode. Also TBO-MWNTs modified GC electrodes exhibiting a strong and stable electrocatalytic response toward β-nicotinamide adenine dinucleotide (NADH) were described. Compared with a bare GC electrode, the TBO-MWNTs modified GC electrodes could decrease the oxidization overpotential of NADH by 730 mV, with a peak current at 0.0 V, since there was a positively synergistic electrocatalytic effect between the MWNTs and TBO toward NADH. Furthermore, the TBO-MWNTs modified GC electrodes had perfect performances, such as a low detection limit (down to 0.5 µM), being very stable (the current diminutions is lower than 6% in a period over 35 min), a fast response (within 3 s), and a wide linear range (from 2.0 µM to 3.5 mM). Such an ability of TBO-MWNTs to promote the NADH electron-transfer reaction suggests great promise for dehydrogenase-based amperometric biosensors.

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