Inactivation of proteins by irradiation of gold nanoparticles with nano- and picosecond laser pulses

Irradiation of 15 nm gold particles with nano- and picosecond laser pulses can create locally temperatures beyond the critical point of water. Due to the short heating times the temperature is localised to the vicinity of the particles. Under irradiation with nano- and picosecond pulses an inactivation of the enzymes alkaline phosphatase and chymotrypsin which were bound to the surface of the particles was observed. As expected by strong temperature gradient caused by the short irradiation time the protein inactivation is localized within a few tens of nanometers when picosecond pulses were used. This was shown by irradiating gold protein conjugates in which the protein was bound via two antibodies to the particle.