Toward Levofloxacin Monitoring in Human Urine Samples by Employing the LoC-SERS Technique

The pharmacokinetics of antibiotics such as levofloxacin exhibits large interindividual differences, questioning the value of fixed dose regimens and warranting individual dosing based on therapeutic drug monitoring. Here, in a proof of principal study, it is shown that levofloxacin can be detected in human urine samples by employing lab-on-a-chip surface enhanced Raman spectroscopy (LOC-SERS). First, artificial urine is used as a matrix in-order to get insights into the influence of different parameters. such as matrix complexity, aggregation time, and matrix dilution on the overall SERS signal. Seeond, three anonymized individual and three, pooled urine samples originating from patients undergoing either no or unknown medical treatments have been spiked with the target analyte. Measurements were performed with a benchtop and a portable Raman setup. In all six samples urinary levofloxacin concentrations between 0.45 mM (162.6 mu g/mL). and 1.8 mM (650.5 mu g/mL) have been successfully-detected. According to the literature, the, normal levofloxacin concentration in urine is 1.38 mM +/- 0.68 mM with a minimum measured concentration of 0.45 mM after 4-h from the administration of a 500 mg dose. The presented results therefore show that LoC-SERS is a promising bioanalytical--tool for urine analysis.