Multi-wall carbon nanotube-based electrochemical sensor for sensitive determination of Sudan I

Herein, an electrochemical sensor for sensitive and convenient determination of Sudan I was developed based on the multi-wall carbon nanotube (MWNT) thin film-modified electrode. Owing to the unique properties of MWNT such as huge surface area, strong adsorptive ability, subtle electronic proper-ties and catalytic ability, the electrochemical oxidation signal of Sudan I significantly increases at the MWNT-based electrochemical sensor, suggesting that NWNT film exhibits obvious enhancement effect to the determination of Sudan I. Based on this, a sensitive and convenient electrochemical method was developed for the determination of Sudan L The linear range is over the range from 0.01 mg L-1 (4.03 x 10(-8) mol L-1) to 1.0 mg L-1 (4.03 x 10(-6) mol L-1), and the limit of detection is 5.0 mu g L-1 (2.01 x 10(-8) mol L-1) after 3-min accumulation. Finally, this sensor was successfully employed to detect Sudan I in some hot chili samples. (C) 2008 Elsevier B.V. All rights reserved.