title: Optical detection of harmonic oscillations in fluorescent dye-loaded microbubbles ensonified by ultrasound.
abstract: A new optical contrast agent has been developed by exposing dye-loaded microbubbles to a rapidly-cooled thermal treatment to homogenize the dye distribution across the surface. Ultrasound causes these microbubbles to oscillate in size which changes the self-quenching efficiency of the dye molecules creating a "blinking" signal. We demonstrate for the first time that these microbubbles can reproducibly generate second, third, and even fourth harmonic fluorescence intensity modulations, in addition to the fundamental frequency of the driving ultrasound. Detecting these harmonic signals could produce a higher signal-to-noise ratio for fluorescence imaging in medical applications by allowing fundamental frequency interference and artifacts to be filtered out.
authors.forename: Carolyn E
authors.initials: CE
authors.lastname: Schutt
authors.forename: Stuart
authors.initials: S
authors.lastname: Ibsen
authors.forename: Michael
authors.initials: M
authors.lastname: Benchimol
authors.forename: Mark
authors.initials: M
authors.lastname: Hsu
authors.forename: Sadik
authors.initials: S
authors.lastname: Esener
mesh_terms: D003287:Contrast Media; D005456:Fluorescent Dyes; D006358:Hot Temperature; D045423:Microbubbles; D000069453:Ultrasonic Waves
chemical_list: D003287:Contrast Media; D005456:Fluorescent Dyes