Green synthesis and molecular recognition ability of patuletin coated gold nanoparticles

Patuletin isolated from Tagetespatula was used as a capping and reducing agent to synthesize in one pot gold nanoparticles capped with patuletin. Conjugation of gold with patuletin was confirmed by FT-IR and UV–visible spectroscopy and amount of patuletin conjugated to gold nanoparticles was found to be 63.2% by weight. Particle sizes were measured by atomic force microscopy (AFM) and were found to have a mean diameter of about 45nm. Patuletin-coated gold nanoparticles were found to be highly fluorescent. To examine their potential as chemical sensors, they were contacted with fourteen different drugs. Of these drugs, only one, piroxicam, was found to quench luminescence. Quenching obeyed Beer's law in a concentration range of 20–260µM. Important for molecular recognition applications, fluorescence quenching by piroxicam was not affected by pH variation, elevated temperatures, addition of other drugs and addition of blood plasma to the colloidal suspensions. [Display omitted] •Patuletin is a natural product which was isolated from the medicinal plant Tagetes patula.•The patuletin was used as reducing agent and stabilizing agent for the formation of nanoparticles.•The nanoparticles were characterized through UV–vis, FT-IR, MALDI-TOF and AFM.•The chemosensing potential of the nanoparticles was evaluated against a number of drugs.•The nanopaticles coated with patuletin showed selective response towards piroxicam.