Levofloxacin determination in urine by photoluminescence spectroelectrochemistry

• Novel Photoluminescence-spectroelectrochemistry cell for screen-printed electrodes. • Photoluminescence-spectroelectrochemistry determination of levofloxacin. • Quantification of levofloxacin in tap water samples in the limit of detection range. • Determination of levofloxacin in urine samples without interfering uric acid. Photoluminescent spectroelectrochemistry (PL-SEC) has scarcely been used for quantitative purposes. The present work demonstrates the effectiveness of PL-SEC in addressing real-world analytical challenges through the quantitative analysis of the antibacterial drug levofloxacin. This study examines the behavior of levofloxacin in samples containing potentially interfering substances, with the aim of simulating the conditions encountered in real scenarios. Fluorescence remains among the most specific techniques in qualitative and quantitative analysis. Here, the evolution of levofloxacin fluorescence spectra recorded during a PL-SEC experiment are found to be very useful for identifying and quantifying levofloxacin in tap water and urine samples. With this objective, a novel PL-SEC cell has been designed, constructed and tested that simplifies significantly the performance of these kind of experiments and favors the reproducibility in analytical determinations. The use of appropriate calibration models provided by PL-SEC experiments has facilitated the determination of levofloxacin. This outcome validates the efficacy and the suitability of this multi-response technique for the accurate measurement of this molecule, particularly in context involving low concentrations and complex samples. The proposed methodology has been demonstrated to be very simple, sensitive reaching a limit of detection of 0.17 µM, and highly reproducible. For electrochemical determinations the reproducibility is less than 7.5 % and for fluorescent quantification, it is below 3.5 %. The low data dispersion should also be highlighted, as evidenced by %RSD values below 7 %, thus making it a suitable candidate for use as a reference method in quantitative analysis.