title: Whispering gallery mode bio-sensor for label-free detection of single molecules: thermo-optic vs. reactive mechanism.
abstract: Thermo-optic and reactive mechanisms for label-free sensing of bio-particles are compared theoretically for Whispering Gallery Mode (WGM) resonators (sphere, toroid) formed from silica and stimulated into a first order equatorial mode. Although it has been expected that a thermo-optic mechanism should "greatly enhance" wavelength shift signals [A.M. Armani et al, Science 317, 783-787 (2007)] accompanying protein binding on a silica WGM cavity having high Q (10(8)), for a combination of wavelength (680 nm), drive power (1 mW), and cavity size (43 microm radius), our calculations find no such enhancement. The possible reasons for this disparity are discussed.
authors.affiliation: MicroParticle PhotoPhysics Lab, Polytechnic Institute of NYU, Brooklyn, New York 11201 USA. SArnold935@aol.com
authors.forename: S
authors.initials: S
authors.lastname: Arnold
authors.forename: S I
authors.initials: SI
authors.lastname: Shopova
authors.forename: S
authors.initials: S
authors.lastname: Holler
mesh_terms: D001704:Biopolymers / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D013817:Thermography / Q000295:instrumentation*
chemical_list: D001704:Biopolymers