Porous photonic crystal external cavity laser biosensor

Photonic crystal;Label-free biosensor;External cavity laser

Huang, Qinglan ; Cunningham ; Brian T.

关键词: Photonic crystal;    Label-free biosensor;    External cavity laser;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/97759/HUANG-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

We report the design, fabrication, and testing of a photonic crystal (PhC) biosensor structure that incorporates a porous high refractive index TiO2 dielectricfilm that enables immobilization of capture proteins within an enhanced surface-area volume that spatially overlaps with the regions of resonant electromagneticfields where biomolecular binding can produce the greatest shifts in photonic crystal resonant wavelength. Despite the nanoscale porosity of the sensor structure, the PhC slab exhibits narrowband and high efficiency resonant reflection, enabling the structure to serve as a wavelength tunable element of an external cavity laser. In the context of sensing small molecule interactions with much larger immobilized proteins, we demonstrate that the porous structure provides 3.7x larger biosensor signals than an equivalent nonporous structure, while the external cavity laser (ECL) detection method provides capability for sensing picometer-scale shifts in the PhC resonant wavelength caused by small molecule binding. The porous ECL achieves a record high figure of merit for label-free optical biosensors.