Simple fluorescence optosensing probe for spermine based on ciprofloxacin-Tb3+ complexation.

We developed a facile detection method of spermine based on the fluorescence (FL) quenching of the ciprofloxacin-Tb³⁺ complex, which shows astrong green emission. Ciprofloxacin (CP) makes efficient bondings to Tb³⁺ ion as a linker molecule through carboxylic and ketone groups to form a kind of lanthanide coordination polymer. The addition of spermine that competes with Tb³⁺ ions for the interaction with CP due to its positive charge brings about weakened coordination linkage of CP and Tb³⁺. The probe exhibited high sensitivity, selectivity, and good linearity in the range of 2–180 μM with a low limit of detection of 0.17 μM. Moreover, we applied this method on the paper strip test (PST), along with the integration of a smartphone and Arduino-based device. The practical reliability of the developed probe was evaluated on human serum samples with acceptable analytical results. [ABSTRACT FROM AUTHOR]