Aerosol Based Fabrication of Thiol-Capped Gold Nanoparticles and Their Application for Gene Transfection

In this study, an ambient-spark-produced-Au-nanoparticle-laden nitrogen gas was mixed with an atomized solution of 1-hexanethiol [CH3(CH2)(5)SH] and ethanol (EtOH). The Au nanoparticles reacted with 1-hexanethiol in the atomized droplets to form capped gold nanoparticles, whose size distributions were measured for varying volumetric fractions of 1-hexanethiol. By increasing the thiol concentration from 0.1% to 1.0% (v/v), the size distribution of merged particles (Au-thiol) was changed from bimodal (showing a superposition of individual distributions of Au and droplets) to unimodal (showing only a droplet-like distribution, with the Au distribution eliminated) configuration. The latter phenomenon is attributed to quantitative incorporation of Au nanoparticles into atomized particles. Measurements of cell viability and transfection revealed that even though the merged particles had a higher cytotwdcity (similar to 78% in cell viability > similar to 49% for polyethyleneimine, PEI) than that did chitosan (similar to 96%), the transfection (2.56 X 10(6) in RLU mg(-1)) of gene was higher than those for chitosan (7.63 x 10(4)) and PEI (6.84 X 10(5)).