An electrochemical sensor for voltammetric detection of ciprofloxacin using a glassy carbon electrode modified with activated carbon, gold nanoparticles and supramolecular solvent.

A highly sensitive and novel electrochemical sensor for ciprofloxacin (CIP) has been developed using gold nanoparticles deposited with waste coffee ground activated carbon on glassy carbon electrode (AuNPs/AC/GCE) and combined with supramolecular solvent (SUPRAS). The fabricated AuNPs/AC/GCE displayed good electrocatalytic activity for AuNPs. The addition of SUPRAS, prepared from cationic surfactants namely didodecyldimethylammonium bromide (DDAB) and dodecyltrimethylammonium bromide (DTAB), increased the electrochemical response of AuNPs. The detection of CIP was based on the decrease of the cathodic current of AuNPs. The electrochemical behavior of the modified electrode was investigated using cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Under optimum conditions, the calibration plot of CIP exhibited a linear response in the range 0.5-25 nM with a detection limit of 0.20 nM. The fabricated electrochemical sensor was successfully applied to determine CIP in milk samples with achieved recoveries of 78.6-110.2% and relative standard deviations of <8.4%. The developed method was also applied to the analysis of pharmaceutical formulation and the results were compared with high-performance liquid chromatography.Graphical abstract.