Photothermal and accompanied phenomena of selective nanophotothermolysis with gold nanoparticles and laser pulses

In medical applications of laser and nanotechnology to diagnosis and treat cancer or microorganisms, understanding of Used-induced photothermal (PT) and accompanied phenomena around nanoparticles are crucial for optimization and bringing this promising technology to bedside. We analyzed the main PT-based effects in mid around gold nanoparticles under action of short (nano-, pico-, and femtosecond) laser pulses with focus on photoacoustic effects due to the thermal expansion of nanoparticles and liquid around them thermal protein denaturation, explosive liquid vaporization, melting mid evaporation of nanoparticle, optical breakdown initiated by nanoparticles and accompanied to shock waves and explosion (fragmentation) of gold nanoparticles. Characteristic parameters for these processes such as the temperature and pressures levels, and laser intensity thresholds among others are summarized to provide basis for comparison of different mechanisms of selective nanophotothermolysis and diagnostics of different targets (e.g., cancer cells, bacteria, viruses). [GRAPHICS] The dependencies of the vapor pressure p(1) (1), vapor mass M-1 (2), mid outer radius of the vapor blanket R-b (3) of) t at t(p) = 1 x 10(-9) s for I-n = 1.4 x 10(7) W/cm(2), r(0) = 30 nm (C) 2008 by Astro Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA