A molecularly imprinted polymer-based triple-ratio fluorescence nanosensor integrated with a paper-based microfluidic chip for rapid detection of enoxacin.

Enoxacin (ENX), a commonly used fluoroquinolone antibiotic, has raised environmental concerns due to its widespread use and resulting pollution. This study presents a novel approach for the rapid and sensitive detection of ENX in aquatic environments using molecularly imprinted polymer-based triple-ratio fluorescence (MIP-TRF) nanosensor. The nanosensor is constructed based on a photoinduced electron transfer (PET) mechanism, combining the high selectivity of molecular imprinting technology with the high sensitivity and anti-interference capability of triple-ratio fluorescence. By optimizing modifiers, eluents, and reaction conditions, the nanosensor demonstrates excellent selectivity and sensitivity, with a detection limit as low as 0.008 mg/L and good linearity over a concentration range of 0.05-7.0 mg/L. The recovery rate in river water samples was between 98.88 % and 102.76 %. To assess the potential application of the sensor, preliminary tests were also conducted by integrating the MIP-TRF nanosensor with a paper-based microfluidic chip, showing that the sensor offers higher detection speed, simplicity, and cost-effectiveness compared to traditional methods. This provides an efficient and convenient solution for the environmental monitoring of ENX and similar contaminants.