A Newly Developed Electrocatalytic Oxidation and Voltammetric Determination of Curcumin at the Surface of PdNp-graphite Electrode by an Aqueous Solution Process with Al³⁺

• Main Authors: Semiha Çakır, Ender Biçer, Emine Yılmaz Arslan
• Format: Article
• Language: English
• Published: Croatian Chemical Society 2015-07-01
• Series: Croatica Chemica Acta
• Online Access: http://hrcak.srce.hr/file/209499
• ISSN: 0011-1643; 1334-417X

In the first stage, the palladium nanoparticles (PdNps)-coated graphite electrode (PdNp/GE) has been prepared. Scanning electron microscopy (SEM) technique showed that the palladium nanoparticles were uniformly distributed with an average particle diameter of 60–75 nm. And then, a novel-modified electrode has been developed by the physical deposition of Al³⁺ ions on palladium nanoparticles (PdNps)-coated graphite electrode (Al³⁺/PdNp/GE). This modified electrode was characterized by square-wave voltammetry (SWV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The sensitivities of PdNp/GE and Al³⁺/PdNp/GE electrodes were tested with dopamine. Al3+/PdNp/GE exhib¬ited a catalytic activity for curcumin oxidation. The square-wave voltammogram of curcumin in phosphate buffer (pH = 2) gave an anodic peak at 0.56 V. The anodic peak current of curcumin was found to be linearly related to its concentration in the range of 3.0×10^-8 M to 6.0×10^-7 M with a detection limit of 2.2×10^-8 M. It was also found that the novel Al³⁺/PdNp/GE electrode had the best sensitivity when compared to glassy carbon electrode (GCE), hanging mercury drop electrode (HMDE) and glassy carbon electrode electropolymerized with acid chrome blue K (poly-ACBK/GCE), used for the determination of curcumin. The curcumin was detected in marketed spices sample of turmeric powder. Pure turmeric powder had the highest curcumin concentration, averaging 4.317±0.175 % by weight.