Laser synthesis of hybrid nanoparticles for biomedicine

The extraordinary properties of size-tunable nanoparticles (NPs) have given rise to their widespread applications in Nanophotonics, Biomedicine, Plasmonics etc. Semiconductor and metal NPs have found a number of significant applications in the modern biomedicine due to ultrasmall sizes (1-10 nm) and the size-dependent flexibility of their optical properties. In the present work passive Q-switched Nd:YAG pulsed laser was used to synthesize NPs by method of laser ablation in different liquids. For cases of hybrid metal NPs we have demonstrated that plasmon resonance can be modified and tuned from the plasmon resonances of pure metal NPs. The shifted plasmon resonance frequency at 437 nm for Au-Ag hybrid NPs, and 545 nm for Au-Cu hybrid NPs have been observed. Effectiveness of biotissue ablation in the case of the tissue sample that colored with metal NPs was approximately on 4-5 times larger than for the sample with non-colored area. Laser welding for deep-located biotissue layers colored by metal NPs has been realized. The luminescence properties of the colloidal hybrid Si-Ni nanoparticles' system fabricated by pulsed laser ablation are also considered. The red-shifted photoluminescence of this system has been registered in the blue range of the spectrum because of the Stark effect in the Coulomb field of the charged Ni nanoparticles. Summarizing, the knowledge of peculiarities of optical properties of hybrid NPs is very important for biomedical applications. More complex nanoassemblies can be easily constructed by the presented technique of laser synthesis of colloidal QDs including complexes of NPs of different materials.