Label free dual-mode sensing platform for trace level monitoring of ciprofloxacin using bio-derived carbon dots and evaluation of its antioxidant and antimicrobial potential

Being a persuasive antibiotic, ciprofloxacin is widely administered to patients and its excessive discharge has generated a keen interest among researchers for its detection in water resources. Therefore, the current work utilizes the virtues of carbon dots synthesized from the leaves of Ocimum sanctum as an economical and convenient bimodal stratagem for the detection of ciprofloxacin via an electrochemical and fluorometric approach. The insight into photostability, size, morphology, and optical studies of the carbon dots was tested to enhance their scope in sensing. The excellent photoluminescence-based excitation-dependent behavior with a quantum yield of 46.7% and non-requirement of any kind of labeled surface variations for amending their fluorescence and electrochemical properties have further supported the utilization of as-prepared carbon dots in trace-level monitoring of ciprofloxacin. The fluorescence emission intensity and peak current were enhanced by many folds via the application of Ocimum sanctum– derived carbon dots. The synergetic effect of carbon dots has possessed a linear relationship between the peak current/emission intensity within the range of 0 to 250 μM of ciprofloxacin and the lowest detection limit value was found to be 0.293 and 0.0822 μM with fluorometric and electrochemical methods, respectively. The sensor demonstrated excellent applicability for the estimation of ciprofloxacin and acts as a high-performance dual sensor for further applications. Graphical Abstract