Sensitive electrochemical determination of luteolin in peanut hulls using multi-walled carbon nanotubes modified electrode

A simple and highly sensitive electrochemical method was developed for the determination of trace-level luteolin, based on the multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE). The electrochemical behaviours of luteolin indicate that MWNTs modified glassy carbon electrode (MWNTs/GCE) can greatly enhance the electrocatalytic activity towards the redox of luteolin. It leads to a considerable improvement of the redox peak current for luteolin and allows the development of a highly sensitive voltammetric sensor for the determination of luteolin. A series of experimental parameters including the pH of supporting electrolyte, accumulation potential and time were optimised. The results showed that the oxidative peak currents increased linearly with the concentration of luteolin in the range of 2.0 x 10(-1)9 to 3.0 x 10(-9) M, with a detection limit of 6.0 x 10(-11) M (S/N = 3). The analytical performance of this sensor has been evaluated for detection of luteolin in peanut hulls as a real sample. (C) 2011 Elsevier Ltd. All rights reserved.