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

Abstract

A β-cyclodextrin–graphene (β-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 β-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 μM to 18 μM, the limit of detection was 0.12 μM (3σ method), with a correlation coefficient of 0.998. The electrode showed good selectivity, reproducibility and stability. Obviously, the collected amounts of DEHP by β-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.