Gold nanoparticle microemulsion films with tunable surface plasmon resonance signal

Composite films were prepared by the dip-coating method. An organosol of Au nanoparticles (6.3+0.4 +0.4 nm) was used as the reaction mixture. The nanoparticles were stabilized with sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The prepared films were formed of an AOT layer with encapsulated Au nanoparticles (i.e. Au@AOT films). The films demonstrated a stable plasmon effect. The variation of the immersion number of the glass substrate from 1 to 10 allowed the adjustment of the plasmonic properties. The absorption intensity and maximum wavelength of the surface plasmon resonance were found to change from 0.183 to 0.245 and from 529 +2 to 539+2 +2 nm, respectively. The plasmonic properties were found to correlate with the film thickness, roughness, and morphology. An increase in the concentration of Au nanoparticles improves the film's mechanical strength and wettability.