Intrinsically fluorescent and quercetin loaded highly crosslinked polyphosphazene nanospheres: synthesis,...

Highly crosslinked, inorganic-organic hybrid and intrinsically fluorescent polyphosphazene nanospheres bearing hydroxyl groups on the surface are facilely generated via a one-pot polycondensation of octachlorocyclotetraphosphazene, fluorescein and quercetin. The resulting nanospheres were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), X-ray diffraction analysis (XRD) and ultraviolet-visible spectroscopy (UV-vis) techniques. The average diameter of the nanospheres was determined as 379 nm. Also, quercetin which is both a monomer and an anticancer drug was loaded to the nanospheres as 446 mg g^-1. The obtained nanospheres possess outstanding disperse ability in both aqueous and organic solvents. Moreover, the nanospheres exhibited intrinsically fluorescence intensity and outstanding photobleaching stability under ultraviolet-visible irradiation, due to the highly crosslinked and inorganic-organic hybrid structure. Owing to these superior properties and novelty of synthesized nanospheres, they have a great potential in many applications such as fluorescent labels, sensors, cell imaging and as a nanocarrier of quercetin for cancer treatment.