Analytical Sciences

Abstract − Analytical Sciences, 31(8), 799 (2015).

A Nicotinamide Adenine Dinucleotide Dispersed Multi-walled Carbon Nanotubes Electrode for Direct and Selective Electrochemical Detection of Uric Acid
Yan CHEN,*,** Yiwei LI,* Yaohong MA,* Qingjun MENG,* Yan YAN,* and Jianguo SHI*
*Biology Institute of Shandong Academy of Sciences, Key Laboratory for Biosensors of Shandong Province, Jinan 250014, P. R. China
**Institute of Oceanology, Chinese Academy of Science, Qingdao 266071, P. R. China
A nanocomposite platform built with multi-walled carbon nanotubes (MWCNTs) and nicotinamide adenine dinucleotide (NAD+) via a noncovalent interaction between the large π systems in NAD+ molecules and MWCNTs on a glassy carbon substrate was successfully developed for the sensitive and selective detection of uric acid (UA) in the presence of ascorbic acid (AA), dopamine (DA). NAD+ has an adenine subunit and a nicotinamide subunit, which enabled interaction with the purine subunit of UA through a strong π–π interaction to enhance the specificity of UA. Compared with a bare glassy carbon electrode (GCE) and MWCNTs/GCE, the MWCNTs-NAD+/GCE showed a low background current and a remarkable enhancement of the oxidation peak current of UA. Using differential pulse voltammetry (DPV), a high sensitivity for the determination of UA was explored for the MWCNTs-NAD+ modified electrode. A linear relationship between the DPV peak current of UA and its concentration could be obtained in the range of 0.05 – 10 μM with the detection limit as low as 10 nM (S/N = 3). This present strategy provides a novel and promising platform for the detection of UA in human urine and serum samples.