title: Single virus and nanoparticle size spectrometry by whispering-gallery-mode microcavities.
abstract: Detecting and characterizing single nanoparticles and airborne viruses are of paramount importance for disease control and diagnosis, for environmental monitoring, and for understanding size dependent properties of nanoparticles for developing innovative products. Although single particle and virus detection have been demonstrated in various platforms, single-shot size measurement of each detected particle has remained a significant challenge. Here, we present a nanoparticle size spectrometry scheme for label-free, real-time and continuous detection and sizing of single Influenza A virions, polystyrene and gold nanoparticles using split whispering-gallery-modes (WGMs) in an ultra-high-Q resonator. We show that the size of each particle and virion can be measured as they continuously bind to the resonator one-by-one, eliminating the need for ensemble measurements, stochastic analysis or imaging techniques employed in previous works. Moreover, we show that our scheme has the ability to identify the components of particle mixtures.
authors.affiliation: Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130, USA. jzhu@seas.wustl.edu
authors.forename: Jiangang
authors.initials: J
authors.lastname: Zhu
authors.forename: Şahin Kaya
authors.initials: ŞK
authors.lastname: Özdemir
authors.forename: Lina
authors.initials: L
authors.lastname: He
authors.forename: Da-Ren
authors.initials: DR
authors.lastname: Chen
authors.forename: Lan
authors.initials: L
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D006046:Gold / Q000737:chemistry; D009980:Influenza A virus / Q000737:chemistry*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry; D013057:Spectrum Analysis / Q000379:methods*; D014771:Virion / Q000737:chemistry
chemical_list: D011137:Polystyrenes; D006046:Gold