title: Sono-photoacoustic imaging of gold nanoemulsions: Part I. Exposure thresholds.
abstract: Integrating high contrast bubbles from ultrasound imaging with plasmonic absorbers from photoacoustic imaging is investigated. Nanoemulsion beads coated with gold nanopsheres (NEB-GNS) are excited with simultaneous light (transient heat at the GNS's) and ultrasound (rarefactional pressure) resulting in a phase transition achievable under different scenarios, enhancing laser-induced acoustic signals and enabling specific detection of nanoprobes at lower concentration. An automated platform allowed dual parameter scans of both pressure and laser fluence while recording broadband acoustic signals. Two types of NEB-GNS and individual GNS were investigated and showed the great potential of this technique to enhance photoacoustic/acoustic signals. The NEB-GNS size distribution influences vaporization thresholds which can be reached at both permissible ultrasound and light exposures at deep penetration and at low concentrations of targets. This technique, called sono-photoacoustics, has great potential for targeted molecular imaging and therapy using compact nanoprobes with potentially high-penetrability into tissue.
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States.
authors.forename: Bastien
authors.initials: B
authors.lastname: Arnal
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States ; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA 98105-6698, United States.
authors.forename: Camilo
authors.initials: C
authors.lastname: Perez
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States.
authors.forename: Chen-Wei
authors.initials: CW
authors.lastname: Wei
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Xia
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States ; University of Washington, Department of Chemical Engineering, Box 351750, Seattle, WA 98195-1750, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Lombardo
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States ; International Laser Center, Moscow State University, Moscow, Russian Federation.
authors.forename: Ivan
authors.initials: I
authors.lastname: Pelivanov
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States ; Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, WA 98105-6698, United States.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Matula
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States ; University of Washington, Department of Chemical Engineering, Box 351750, Seattle, WA 98195-1750, United States.
authors.forename: Lilo D
authors.initials: LD
authors.lastname: Pozzo
authors.affiliation: University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States.
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
keywords: Gold nanoparticles; Nanoemulsion; Non-linear photoacoustics; Perfluorocarbon; Photoacoustic cavitation; Vaporization