Analysis of optical properties of diallyldimethylammonium chloride dielectric-coated gold nanospheres for targeted drug delivery

This study theoretically analyzed the optical properties and electric field enhancement of gold nanospheres. Based on numerical analysis, the gold nanospheres were coated experimentally with diallyldimethylammonium chloride (C8H16ClN) for targeted drug delivery. Numerically, a resonance peak for 10 nm nanospheres was observed at 510 nm. As the radius increased from 10 nm to 100 nm, the resonance peak shifted from 510 nm to 605 nm. The nanosphere radius also affected the extinction cross-section. The resonance peaks showed a red shift as the radius of the nanosphere increased. For experiment analysis, gold nanospheres were synthesized using a seed-mediated technique and then coated with different concentrations of C8H16ClN. The UV absorbance by the nanospheres increased with an increase in the concentration of C8H16ClN from 10 mg ml-1 to 20 mg ml-1. UV-vis spectrum confirmed a rise in resonance peaks with increasing coating concentration. The coated gold nanospheres were used to deliver the doxorubicin-HCl (DOX-HCl) drug. Maximum drug release was observed when the temperature was set at 50 degrees C. It was concluded that the nanospheres, coated with 20 mg ml-1 of C8H16ClN, are excellent candidates for drug delivery applications. The gold nanospheres with a radius of 50 nm were best for target drug delivery, and the particles above 50 nm were best for thermal therapies for cancer treatment.