β–Cyclodextrin carbon nanotube-enhanced sensor for ciprofloxacin detection

ABSTRACT

A simple and expedite electrochemical methodology was developed for the determination of ciprofloxacin, based on a glassy carbon (GC) electrode modified by a combination of multi-walled carbon nanotubes (MWCNT) with β–cyclodextrin (β–CD) incorporated in a polyaniline film. The combined use of β–CD and MWCNT in the electrochemical sensor leads to a significant signal improvement. The β–CD/MWCNT modified GC electrode exhibited efficient electrocatalytic behavior in the oxidation of ciprofloxacin with relatively high sensitivity, stability and lifetime. Molecular modeling studies showed that ciprofloxacin binds preferably to β–CD rather than to CNT edges, leading to an improved sensitivity of the sensor. Under optimized conditions, a linear calibration curve was obtained for ciprofloxacin in the concentration range 10–80 µM with a detection limit of 50 nM. The analytical performance of this sensor was evaluated for the detection of ciprofloxacin in a wastewater treatment plant effluent.

KEYWORDS:

• Ciprofloxacin
• electrochemical sensor
• β–cyclodextrin
• carbon nanotubes

Acknowledgments

The authors thank J.J. Vandamme and V. Rahemi for their assistance in data collection during the implementation of our procedure.

Funding

MMF acknowledges support by the Portuguese “Fundação para a Ciência e a Tecnologia” through the program Ciência 2008 and access to computing facilities provided by the Project “SearchON2: Revitalization of HPC infrastructure of UMinho” (NORTE070162FEDER000086).