Fabrication of Fluorescent Nanodot Arrays on Metal Films for Application in Near-Field Optical Media

We present the fabrication of nanodot arrays on silver and gold films by self-assembly of poly(styrene)- block -poly(2-vinylpyridine) (PS–P2VP) allowing various time intervals between vacuum evaporation and the dripping of a solution of PS–P2VP in toluene. Uniform and regularly aligned nanodots were formed on the gold film after 48 h. We measured the contact angle of water droplets on the two metal surfaces separately for each specified time interval. As the time interval increased, the contact angle at the silver surface increased. In contrast, the contact angle at the gold surface decreased. Thus, it may be concluded that higher hydrophilicity of a metal surface improves the uniformity and alignment regularity of the nanodots. We formed fluorescent nanodots by mixing rhodamine 6G in the toluene solution of PS–P2VP. We have succeeded in observing fluorescent dots about 100 nm in diameter using a fluorescence microscope.