Sensitive and rapid detection of ciprofloxacin and ofloxacin in aqueous samples by a facile and green synthesized copper nanocluster as a turn-on fluorescent probe

The present method reports a rapid, inexpensive and sensitive sensing system based on fluorescence turn-on strategy for trace detection of ciprofloxacin (CIP) and ofloxacin (OFL) in aqueous samples. In a one pot method, copper nanocluster whose dimensions are less than 15 nm, were easily prepared and decorated with sodium gluconate (Gl@CuNCs) as a biocompatible material.The Gl@CuNCs were characterized with XRD, TEM, DLS, TG-DTA techniques as well UV–Vis, FT-IR and fluorescence spectroscopies.The maximum fluorescence emission of Gl@CuNCs at 414 nm with excitation at 322 nm shifted to higher wavelength upon addition of CIP and OFL. A good linear relationship between fluorescence emission and drug concentration was achieved in the concentration range of 0.005–0.3 μg mL−1 (15–900 nM for CIP and 14–830 nM for OFL). The limits of detection (LOD) for the determinations of CIP and OFL were calculated to be 9 and 8 nM, respectively. Furthermore, even a 100-fold higher concentration of interfering species had no significant effect on the detection of CIP and OFL. The proposed method was successfully used to determine CIP and OFL in drinking water, cow milk, human urine and serum samples with satisfactory recoveries.