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The physics of extreme sensitivity in whispering gallery mode optical biosensors

Lopez-Yglesias, Xerxes and Gamba, Jason M. and Flagan, Richard C. (2012) The physics of extreme sensitivity in whispering gallery mode optical biosensors. Journal of Applied Physics, 111 (8). 084701. ISSN 0021-8979. doi:10.1063/1.3698319.

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Whispering gallery mode (WGM) optical biosensors are capable of extraordinarily sensitive specific and nonspecific detection of species suspended in a gas or fluid. Recent experimental results suggest that these devices may attain single-molecule sensitivity to protein solutions in the form of stepwise shifts in their resonance wavelength, λ_R, but present sensor models predict much smaller steps than were reported. This study examines the physical interaction between a WGM sensor and a molecule adsorbed to its surface, exploring assumptions made in previous efforts to model WGM sensor behavior, and describing computational schemes that model the experiments for which single protein sensitivity was reported. The resulting model is used to simulate sensor performance, within constraints imposed by the limited material property data. On this basis, we conclude that nonlinear optical effects would be needed to attain the reported sensitivity, and that, in the experiments for which extreme sensitivity was reported, a bound protein experiences optical energy fluxes too high for such effects to be ignored.

Item Type:Article
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Flagan, Richard C.0000-0001-5690-770X
Additional Information:© 2012 American Institute of Physics. Received 5 January 2012; accepted 22 February 2012; published online 16 April 2012. The authors would like to thank the Jacobs Institute for Molecular Engineering for Medicine at the California Institute of Technology and the NASA Astrobiology Institute through the NAI Titan team managed at JPL under NASA Contract NAS7-03001 for the funding of this project, and the Ayrshire Foundation for their support in making computing resources available.
Funding AgencyGrant Number
Jacobs Institute for Molecular Engineering for MedicineUNSPECIFIED
Ayrshire FoundationUNSPECIFIED
Subject Keywords:adsorption, biosensors; optical sensors; proteins; suspensions; whispering gallery modes
Issue or Number:8
Classification Code:PACS: 87.14.E-; 87.15.B-; 68.43.-h
Record Number:CaltechAUTHORS:20120604-113054673
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Official Citation:The physics of extreme sensitivity in whispering gallery mode optical biosensors Xerxes Lopez-Yglesias, Jason M. Gamba, and Richard C. Flagan, J. Appl. Phys. 111, 084701 (2012), DOI:10.1063/1.3698319
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31797
Deposited By: Jason Perez
Deposited On:04 Jun 2012 20:09
Last Modified:09 Nov 2021 20:00

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