Tagless remote refractometric sensor based on WGMs in quantum dot-embedded microspheres

Shuo Pang; Kenith E. Meissner

doi:10.1117/12.763730

22 February 2008 Tagless remote refractometric sensor based on WGMs in quantum dot-embedded microspheres

Shuo Pang, Kenith E. Meissner

Proceedings Volume 6863, Optical Diagnostics and Sensing VIII; 686303 (2008) https://doi.org/10.1117/12.763730
Event: SPIE BiOS, 2008, San Jose, California, United States

Abstract

Optical resonances in microspheres have recently been applied to biosensing applications. The resonances, known as Whispering Gallery Modes (WGMs) result from the total internal reflection of the light propagating inside the high index spherical surface within a lower index medium. The evanescent field of the WGM, which extends beyond the microsphere surface, is sensitive to the changes in the local refractive index in the surrounding medium. The high Q factor associated with WGMs enables a highly sensitive sensor element. Here we present a refractometric sensor with high sensitivity based on quantum dot (QD) embedded polystyrene microspheres. Ultrashort laser pulses are used to induce two photon excited luminescence from the QDs inside the microspheres. By optimizing the detection area of the microsphere, an enhanced resonance signal to background ratio can be achieved. Theoretical calculations of the resonance peak shifts are compared with the experimental data. Refractometric sensing based on WGMs is a technique that does not require analyte labeling. In this work, QDs are used as a local, broadband light source within the microspheres to enable remote excitation of the resonant modes. The sensor has great potential in many biosensing applications.

Citation Download Citation

Shuo Pang and Kenith E. Meissner "Tagless remote refractometric sensor based on WGMs in quantum dot-embedded microspheres", Proc. SPIE 6863, Optical Diagnostics and Sensing VIII, 686303 (22 February 2008); https://doi.org/10.1117/12.763730

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available