Femtosecond laser synthesized nanohybrid materials for bioapplications

Hybrid nanomaterials were synthesized by adopting femtosecond laser ablation of a ZnO target in pure ethanol. Dye molecules were grafted onto the ZnO nanoparticles by mixing colloidal ZnO–ethanol solution prepared by laser ablation to Tetramethylrhodamine B isothiocyante, or to Rhodamine B solutions. Strongly facetted nanohybrid particles were observed with an average size of 15 nm, by HRTEM measurements. From photoluminescence spectroscopy of the nanohybrids after single and multiphoton excitations, we observed energy transfer from the ZnO nanoparticles towards the attached dye molecules. Moreover, IR excitation spectra of the hybrid nanomaterials reveal the emission of the grafted dye via two photon absorption of the ZnO.