Optica highlights Judith Su's FLOWER device

Sept. 26, 2024

Optics and Photonics News speaks with BME professor Judith Su about groundbreaking biosensing technology.

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Judith Su, associate professor of biomedical engineering and optical sciences at the University of Arizona College of Engineering.

Judith Su authored the study of FLOWER, an ultra-sensitive biosensing system that can be used for a variety of real-world applications.

Optica featured biomedical engineering professor Judith Su and her groundbreaking research with FLOWER, an ultra-sensitive, label-free biosensing system that can detect a single macromolecule.

FLOWER, an acronym for “frequency-locked optical whispering evanescent resonator,” leverages whispering-gallery-mode optical microcavity technology to detect membrane–protein binding events in real time.

“FLOWER is a platform technology, which can be used for many real-world applications, including medical diagnostics as well as food-, air- and water-quality monitoring,” Su said. “We have used FLOWER for diagnostics of ovarian cancer and Alzheimer’s disease, as well as environmental monitoring of toxic industrial chemicals and chemical warfare agent surrogates.”

The core sensing element of FLOWER is a silica microtoroid, a geometry known for long photon confinement times that span hundreds of nanoseconds. First, the microtoroid is functionalized with a synthetic phospholipid membrane doped with membrane receptors. Then, a tunable laser (765 to 781 nm) is coupled to the resonator through a tapered optical fiber within a liquid sample. The laser is also frequency-locked to the resonator so that the wavelength matches the microtoroid resonance.