Hybrid nanoparticle based fluorescence switch for recognition of ketoprofen in aqueous media

A rapid fluorescence method has been developed which describes the sensitive and selective determination of ketoprofen by developing hybrid assemblies composed of silver nanoparticles and organic nanoparticles. Three different ligands were synthesized using various thiourea derivatives and these were processed with organic nanoparticles using a single step re-precipitation method. Hybrid nanoassemblies were developed and consisted of silver nanoparticles and organic nanoparticles, respectively. These were further analysed for their response to various drug molecules and their fluorescence emission spectra were recorded. A non-selective response was observed for hybrid nanoassemblies composed of ethyl isothiocyanate and phenyl isothiocyanate. However, a turn-on fluorescence response to ketoprofen was noticed for the hybrid nanoassembly composed of 1-naphthyl isothiocyanate. Titrations were carried out revealing that with subsequent addition of ketoprofen, a gradual increase in fluorescence emission was noticed. Our sensor can effectively determine ketoprofen up to a detection limit of 34 nM. Moreover, other drug molecules were found to have negligible interference in the sensing of ketoprofen in aqueous media.