Hydroxide assisted synthesis of monodisperse and biocompatible gold nanoparticles with dextran

A simple and rapid approach to synthesize monodisperse and biocompatible gold nanoparticles (AuNPs) employing dextran as a reducing and stabilizing agents at different reaction conditions was described. The obtained dextran-gold nanoparticles (Dex-AuNPs) were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, Fourier transformer infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. The TEM examinations showed the resultant particles were 4-50 nm in size, monodispersity and uniform particle size distribution. Moreover, the size of the nanoparticles can be controlled by varying the concentration of the reactants. UV-Vis spectra showed that the characteristic localized surface plasmon resonance (LSPR) band of AuNPs was at about 525 nm. NMR spectroscopy and FTIR spectroscopic analysis suggested the detailed structural information of dextran before and after synthesis of AuNPs. XRD and selected area electron diffraction (SAED) pattern analysis demonstrated that the colloidal nanoparticles had a well crystallized structure. The experimental analyses revealed that NaOH played an important role in the synthesis of Dex-AuNPs. And the possible formation mechanism of the fabrication of these Dex-AuNPs was also proposed. MTT assay was utilized to evaluate the cytotoxicity of the synthesized Dex-AuNPs on HeLa cells and SiHa cells. These results suggested that the prepared Dex-AuNPs complexes had excellent biocompatibility and acted as a candidate for further biomedical application.