Fabrication of chitosan nanoparticles containing samarium ion potentially applicable for fluorescence detection and energy transfer

Chitosan is a natural polysaccharide that has ideal properties as a polymer nanoparticle for drug delivery applications because it is easy to synthesize, inexpensive, biocompatible, biodegradable, non-immunogenic, and non-toxic. In this study, chitosan nanoparticles were fabricated in an acidic solution in the presence of potassium persulfate using a microwave technique. The effects of the reaction time, temperature, and weight ratio of potassium persulfate/chitosan on the yield and particle size were evaluated. It was found that the yield increased non-linearly, whereas the size of chitosan nanoparticles was 3 nm in the absence of potassium persulfate, which tended to increase with an increase in the potassium persulfate concentration. The chitosan nanoparticles were also treated with samarium for fluorescence detection. The fluorescence intensity at 590 nm of samarium-treated chitosan nanoparticles increased by a factor of more than 20 when compared with the samarium ion itself and was significantly higher than that of the untreated chitosan nanoparticles. It is indicated that chitosan nanoparticles are not only useful for drug carriers, where the drug delivery can be traced by monitoring fluorescence emission, but with the photoemissive properties of chitosan nanoparticles treated with samarium, they could also be applicable as environmentally friendly photocatalysts for the photodegradation of discharged pollutants as well as efficient photosensitizers that participate in energy transfer.