Folate-Conjugated Gold Nanoparticles (Synthesis, Characterization and Design for Cancer Cells Nanotechnology-based Targeting)

A new folate-conjugated gold nanoparticle (AuNP) has been designed to selectively target the folate receptor that is overexpressed on the surface of tumoral cells. For this purpose, we made 4-aminothiophenol, as a bifunctional linker to react with HAuCl4 in the presence of sodium borohydride and it was binded to the AuNP surface through its thiol group. Then, we conjugated amino-terminated nanoparticles to folic acid with an amide-linkage formation. Finally, we evaluated the specific interaction between the folic acid and AuNP by the corresponding observed characteristic bands in the UV-vis and FTIR spectra. Transmission electron microscopic (TEM) images reveal the spherical AuNPs formation induced by the bifunctional linker. Powder X-ray diffraction (XRD) patterns confirmed the metallic face-centered cubic (FCC) lattice structure with (111), (200), (220), and (311) crystal planes. We estimated the average size of the conjugated nanoparticles to be about 5 nm by TEM and XRD. The Elemental analysis and atomic absorption showed 59 % organic molecules on the surfaceof AuNPs