Turn-on fluorescence detection of ciprofloxacin in tablets based on lanthanide coordination polymer nanoparticles

Metal–organic coordination polymers (MOCPs) have emerged as a new family of functional nanomaterials. Here, we report a facile and effective fluorescence method for detecting CIP in tablets using a kind of lanthanide coordination polymer nanoparticle (LCPNP), specifically Eu/GMP NPs, as the sensing platform. Eu/GMP NPs, composed of guanosine monophosphate (GMP) and europium (Eu3+) ion, are by themselves non-luminescent. The addition of ciprofloxacin (CIP) into the Eu/GMP NPs, however, noticeably enhanced their fluorescence due to the strong coordination interaction between CIP and Eu3+, and the improved hydrophobic interior of the LCPNPs resulted in an efficient energy transfer from CIP to Eu3+. The fluorescence intensity of Eu/GMP at 615 nm showed a linear relationship with CIP concentration between 1.0 and 40 μM, with a detection limit of 780 nM. We believe that the proposed time-resolved fluorometric assay based on the Eu/GMP NP lanthanide nanosensor, with its long fluorescence lifetime, has a great potential for using in the testing of biosamples.