A Dual-Signalling Electrochemical Recognition of Naproxen Enantiomers Based on Competitive Host-Guest Interaction of a β-Cyclodextrin/Graphene modified Electrode

A novel chiral architecture was fabricated by electrochemically reduction of graphene oxide on the glassy carbon electrode (GCE) and subsequent electro-oxidation of the electrode in a solution of β-cyclodextrin in phosphate buffer solution of pH 6.0. Morphological and electrochemical characterization of the electrode was conducted using scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The proposed chiral interface was used for recognition of Naproxen drug enantiomers by a competitive Host-Guest interaction between a probe and naproxen enantiomers which takes place in the interface of electrode. Thanks to the good redox properties and high affinity to β -CD, methylene Blue was used as the electrochemical probe. Due to the host-guest interaction, MB molecule can enter into the hydrophobic inner cavity of β-CD, and the MB/ β-CD/ ErGO/GCE displays a remarkable oxidation peak due to MB. In the presence of Naproxen, competitive association to β -CD occurs and the MB molecules are displaced by Naproxen, resulting in a decrease in the reduction peak current of MB. However selective binding properties of the electrode toward Naproxen enantiomers, led to different current changes, were further used for discriminating of enantiomes. Effect of different parameters such as concentration of MB and pH of the supporting electrolyte on enantio-selective discrimination was investigated. This approach provided a new available sensing interface to recognize and determine Naproxen enantiomers by electrochemical technology