Development of a colorimetric sensor based on a peroxidase-like Cu,Fe-TCPP metal–organic framework for detection of fleroxacin

Abstract

The fluoroquinolone pharmaceutical fleroxacin (FLO) has been extensively utilized in the treatment of urinary tract diseases. The quantitative analysis of FLO content is crucial for safeguarding human wellness and protecting ecosystems. In this study, we successfully developed a straightforward colorimetric sensor utilizing peroxidase (POD)-like Cu,Fe-TCPP. Upon the introduction of fleroxacin, the Cu,Fe-TCPP sensor demonstrated an enhancement in absorbance intensity at 652 nm combined with the substrates TMB and H₂O₂. This enhanced response effectively mitigates interference from environmental factors and allows for the efficient differentiation of FLO from diverse fluoroquinolone antibiotics, showcasing an excellent selectivity for FLO detection. A linear correlation between A₆₅₂ and the FLO concentration was established within the range of 0.83–100 ng mL⁻¹, with a limit of detection (LOD) as low as 0.27 ng mL⁻¹. Additionally, satisfactory recovery rates of FLO were achieved in milk samples, indicating the practical applicability of this method. This work presents a promising approach for the fabrication of two-dimensional metal–organic framework (MOF)-based colorimetric sensors for the monitoring of antibiotics.