Multipulse mode of heating nanoparticles by nanosecond, picosecond and femtosecond pulses

Abstract

Nanoparticles are being researched as a noninvasive method for selectively killing cancer cells. With particular antibody coatings on nanoparticles, they attach to the abnormal cells of interest (cancer or otherwise). Once attached, nanoparticles can be heated with UV/visible/IR or RF pulses, heating the surrounding area of the cell to the point of death. Researchers often use single-pulse or multipulse lasers when conducting nanoparticle ablation research. In the present paper, we are conducting an analysis to determine if the multipulse mode has any advantage in heating of spherical metal nanoparticles (such as accumulative heating effect). The laser heating of nanoparticles is very sensitive to the time structure of the incident pulsed laser radiation, the time interval between the pulses, and the number of pulses used in the experiments. We perform time-dependent simulations and detailed analyses of the different nonstationary pulsed laser-nanoparticle interaction modes, and show the advantages and disadvantages of multipulse (set of short pulses) and single-pulse laser heating of nanoparticles. A comparative analysis for both radiation modes (single-pulse and multipulse) are discussed for laser heating of metal nanotargets on nanosecond, picosecond and femtosecond time scales to make recommendations for efficient laser heating of nanomaterials in the experiments.