Photochemical Synthesis of the Bioconjugate Folic Acid-Gold Nanoparticles

In this paper we present a rapid and simple onepotmethod to obtain gold nanoparticles functionalizedwith folic acid using a photochemistry method. Thebioconjugate folic acid-gold nanoparticle was generatedin one step using a photo-reduction method, mixinghydrogen tetrachloroaurate with folic acid in differentratios and varying the illumination time of a mercurylamp (λ= 255 nm). Scanning electron microscopy showeda particle size of around 40-50nm and dynamic lightscattering exhibited that the zeta potential varies from -41to -50mV with different illumination times. Storage in thedark at 4°C prolongs the stability of folic acid-goldnanoparticle suspensions to up to 26 days. Ultravioletvisible and Fourier transform infrared spectroscopyshowed a surface plasmon band of around 534nm andfluorescence spectroscopy exhibited a quenching effect ongold nanoparticles in the fluorescence emission of folicacid and thus confirmed the conjugation of folic acid tothe surface of gold nanoparticles. In this study wedemonstrate the use of a photochemistry method toobtain folic acid-gold nanoparticles in a simple and rapidway without the use of surfactants and long reactiontimes. The photochemical synthesis of FA-AuNPs opensnew perspectives for creating novel functionalnanomaterials for biomedical applications