Fast, Selective and Sensitive Fluorescence Detection of Levofloxacin, Fe3+ and Cu2+ Ions in 100% Aqueous Solution Via Their Reciprocal Recognition

The fluorescence detection of ions and pharmaceutical effluents by using organic chemosensors is a valuable surrogate to the currently existing expensive analytical methods. In this regard, the design of multi-functional chemosensors to recognize desirable guests is of utmost importance. In this study, we first show that levofloxacin (LVO) is able to use as a fluorescent chemosensor for the detection of biologically important Cu2+ (turn-off) and Fe3+ (turn-on) ions via independent signal outputs in 100% aqueous buffer solutions. Next, using the reciprocal recognition of LVO and Fe3+ provides a unique emission pattern for the detection of LVO. This approach exhibited a high specificity to LVO among various pharmaceutical samples, namely acetaminophen (AC), azithromycin (AZ), gemifloxacin (GEM) and ciprofloxacin (CIP) and also showed great anti-interference property in urine. The attractive features of this sensing system are availability, easy-to-use, high sensitivity (limit of detection = 18 nM for Cu2+, 22 nM for Fe3+ and 0.12 nM for LVO), rapid response (5 s) with an excellent selectivity.