Detection of di(2-ethylhexyl) phthalate through graphene-β-cyclodextrin composites by electrochemical impedance spectroscopy

A beta- cyclodextrin-graphene (beta-CD-G) hybrid composite modified glassy carbon electrode for the first time was used for electrochemically detecting di(2-ethylhexyl) phthalate (DEHP), based on the inclusion of DEHP into beta-CD. The electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. At the composites electrode, the impedance value increased linearly with the increasing DEHP concentration in the range of 2 mu M to 18 mu M, the limit of detection was 0.12 mu M (3 sigma method), with a correlation coefficient of 0.998. The electrode showed good selectivity, reproducibility and stability. Obviously, the collected amounts of DEHP by beta-CD-G could be detected through this electrochemical method. Furthermore, this simple and low-cost sensing platform can in principle be extended to the detection of other phthalate esters which can form host-guest complexes with cyclodextrin.