title: Bleaching of plasmon-resonance absorption of gold nanorods decreases efficiency of cell destruction.
abstract: When irradiated with nanosecond laser pulses, gold nanoparticles allow for manipulation or destruction of cells and proteins with high spatial and temporal precision. Gold nanorods are especially attractive, because they have an up-to-20-fold stronger absorption than a sphere of equal volume, which is shifted to the optical window of tissue. Thus, an increased efficiency of cell killing is expected with laser pulses tuned to the near infrared absorption peak of the nanorods. In contrast to the higher-absorption, experiments showed a reduced efficacy of cell killing. In order to explain this discrepancy, transient absorption of irradiated nanorods was measured and the observed change of particle absorption was theoretically analyzed. During pulsed irradiation a strong transient and permanent bleaching of the near-infrared absorption band occurred. Both effects limit the ability of nanorods to destroy cells by nanocavitation. The existence of nanocavitation and transient bleaching was corroborated by optoacoustic measurements.
authors.affiliation: University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Rudnitzki
authors.forename: Marco
authors.initials: M
authors.lastname: Bever
authors.forename: Ramtin
authors.initials: R
authors.lastname: Rahmanzadeh
authors.forename: Katrin
authors.initials: K
authors.lastname: Brieger
authors.forename: Elmar
authors.initials: E
authors.lastname: Endl
authors.forename: Jürgen
authors.initials: J
authors.lastname: Groll
authors.forename: Gereon
authors.initials: G
authors.lastname: Hüttmann
mesh_terms: D002458:Cell Fractionation / Q000379:methods*; D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry* / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D008223:Lymphoma / Q000473:pathology* / Q000503:physiopathology*; D043942:Nanotubes / Q000737:chemistry* / Q000528:radiation effects*; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold