title: Single nanoparticle detection using photonic crystal enhanced microscopy.
abstract: We demonstrate a label-free biosensor imaging approach that utilizes a photonic crystal (PC) surface to detect surface attachment of individual dielectric and metal nanoparticles through measurement of localized shifts in the resonant wavelength and resonant reflection magnitude from the PC. Using a microscopy-based approach to scan the PC resonant reflection properties with 0.6 μm spatial resolution, we show that metal nanoparticles attached to the biosensor surface with strong absorption at the resonant wavelength induce a highly localized reduction in reflection efficiency and are able to be detected by modulation of the resonant wavelength. Experimental demonstrations of single-nanoparticle imaging are supported by finite-difference time-domain computer simulations. The ability to image surface-adsorption of individual nanoparticles offers a route to single molecule biosensing, in which the particles can be functionalized with specific recognition molecules and utilized as tags.
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. bcunning@illinois.edu.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhuo
authors.forename: Huan
authors.initials: H
authors.lastname: Hu
authors.forename: Weili
authors.initials: W
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.forename: Limei
authors.initials: L
authors.lastname: Tian
authors.forename: Hojeong
authors.initials: H
authors.lastname: Yu
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Long
authors.forename: Edmond
authors.initials: E
authors.lastname: Chow
authors.forename: William P
authors.initials: WP
authors.lastname: King
authors.forename: Srikanth
authors.initials: S
authors.lastname: Singamaneni
authors.forename: Brian T
authors.initials: BT
authors.lastname: Cunningham
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003460:Crystallization / Q000379:methods*; D008853:Microscopy / Q000379:methods; D053758:Nanoparticles / Q000032:analysis*; D017785:Photons