Determination of ascorbic acid using Cu (II) complex-modified glass carbon electrode

Ascorbic acid, hereafter referred to as AA, a water soluble vitamin, is an extremely important substance which plays a unique redox and electrochemical role. AA is a compound that takespart in many important life processes [1]. Therefore, AA has been determined by numerous techniques. The oxidation of AA at a glassy carbon electrode gives a very poor electrochemical response. Therefore, developing simple and reliable methods for fabrication of new modifiedelectrodes for AA determination have been always a goal for research groups. Although a few modified electrodes have been used successfully for AA determination, but most of them have certain disadvantages such as considerable leaching of modifier, poor long-term stability, andcontamination. Hence, it is necessary to explore and develop a simple and reliable method tofabricate modified electrodes with other modifiers for electrocatalytic determination of AA [2]. In recent years, the transition metal complexes have been used as modified material on electrodesurface to form chemically modified electrodes. Due to their ability to construct specific stacking and generalized electrostatic interactions, transition metal complexes have been exploited as impactful host matrices for guest molecules with appropriate size and structure [3]. Currently, there are many studies onthe mechanism of action of transition metal complexes and drug molecules. In the present work, aglassy carbon electrode modified with a novel [Cu(L)3]2+ (L = N-(4,5-Diazafluoren-9- ylidene)aniline) complex have been applied to the electrocatalytic oxidation of AA. Under the optimized conditions, the square wave voltammetric peak current of AA increased linearly with concentrations in the range of 1×10-7 to 200×10-4 M and a detection limit of 8.8×10-8 M was obtained. Finally this modified electrode was used for determination of AA in some real samples.

کلیدواژه ها:

Ascorbic acid ، Glassy carbon electrode ، Cu (II) complex ، N-(4 ، 5-Diazafluoren-9-ylidene)aniline