Sol-gel electrode modified with carbon nanotubes as a novel sensor for the voltammetric determination of gallic acid

Gallic acid (C7H6O5) is one of the natural phenolic antioxidants found in black tea, grapes, sumac, saffron and some other plants. Due to the effects of gallic acid in human health, antioxidant and anticancer activities the development of robust and sensitive methods for the determination of this component gains more importance [1]. Recently many techniques have been employed for the determination of GA including spectrophotometry [2], chromatography[3], flow injection [4], resonance light scattering [5] and electrochemical methods [6]. In comparison with other methods electrochemical techniques are simple to perform, rapid,reasonably inexpensive and are appropriate alternative to other methods [7]. At the present study electrochemical behavior of gallic acid at sol-gel electrode modified with carbon nanotubes was investigated using cyclic voltammetry and cronoamperometry.Differential puls voltammetry as a sensitive technique was used for the determination of gallic acid at trace amounts. Some effective parameters such as pH, and concentration and type of supporting electrolyte were optimized. Obtained results showed linear ranges of 0.05 – 2.2 mM and 1.6 – 99 μM and detection limits of13 and 0.96 μM for cyclic voltammetry and differential puls voltammetry respectively. Developed sensor successfully used for the determination of gallic acid at tea sample.

کلیدواژه ها:

Gallic acid ، Sol-gel electrode ، Carbon nanotubes ، Voltammetry