A novel strategy for ketorolac detection based on Turn-on plasmonic enhanced FRET synchronous fluorometric sensor employing micellized chitosan/ AgNPs nanocomposites: preparation and mechanism investigation

Abstract A novel green eco-friendly turn-on FRET sensing strategy was developed for detection of ketorolac (KET). One-pot water-dispersed chitosan stabilized silver nanoparticles (AgNPs) solution was synthesized by complexation of micellized chitosan solution with silver nitrate at low temperature followed by subsequent reduction using sodium borohydride at 70 °C. The preparation method was mild and produced AgNPs solution stable for eight months at 4 °C. Owing to the spectral overlap of the fluorescent spectrum of chitosan and absorption spectrum of AgNPs, a novel sensitive turn-on FRET sensing strategy was established based on enhancement of chitosan fluorescence by electrostatic destabilization of the monodispersed AgNPs upon the addition of KET. The sensor solution was applied for the selective detection of ketorolac from 0.05 to 0.4 μM in injection dosage forms and spiked environmental water samples with no interference either of the KET photocatalyzed degradation product or other interfering structurally related or coexisting substances. The developed strategy showed promising results and could be applied practically for the detection of KET in injection dosage forms and environmental water.