0
Research Papers

Dual closed-loop, optoelectronic, auto-oscillatory detection circuit for monitoring fluorescence lifetime-based chemical sensors and biosensors

[+] Author Affiliations
Emmanuil Rabinovich

University of New Mexico, Center for High Technology Materials, 1313 Goddard, SE, Albuquerque, NM?87106

Tengiz Sviminoshvilli, Michael J. O’Brien

University of New Mexico, Department of Chemical and Nuclear Engineering, Farris Engineering Center #209 Albuquerque, NM?87131

Steven R. J. Brueck

University of New Mexico, Center for High Technology Materials, 1313 Goddard, SE, Albuquerque, NM?87106

Gabriel P. Lopez

University of New Mexico, Department of Chemical and Nuclear Engineering, Farris Engineering Center #209 , Albuquerque, NM?87131 E-mail: gplopez@unm.edu

J. Biomed. Opt. 9(3), 609-617 (May 01, 2004). doi:10.1117/1.1688814
History: Received Apr. 1, 2003; Revised Aug. 14, 2003; Accepted Sep. 4, 2003; Online April 21, 2004
Text Size: A A A

We present a new detection instrument for sensor measurements based on excited-state fluorescence lifetimes. This system consists of a primary optoelectronic loop containing a resonance-type rf amplifier, a modulatable fluorescence-excitation light source, a fiber optic feedback loop (with a gap for a fluorescent sensor), and a photomultiplier tube. A secondary, phase-feedback optoelectronic circuit consists of a long-wavelength-pass optical filter, a second photomultiplier tube, a photodiode, an electronic phase detector, a dc amplifier, and an electronic phase shifter (inserted into the main loop). This phase-feedback circuit is new with respect to our previous work. Under the appropriate conditions, the main loop exhibits self-oscillations, manifesting themselves as sinusoidal rf modulation of light intensity. The phase-feedback circuit detects the modulation phase shift resulting from the finite excited-state lifetimes of a fluorophore. As the excited state lifetime changes, the phase shift from the electronic phase shifter also changes, which results in a shift in self-oscillation frequency. The detection system uses self-oscillation frequency as the detection parameter and has excellent resolution with respect to changes in excited-state lifetime (∼1 ps). © 2004 Society of Photo-Optical Instrumentation Engineers.

© 2004 Society of Photo-Optical Instrumentation Engineers

Citation

Emmanuil Rabinovich ; Tengiz Sviminoshvilli ; Michael J. O’Brien ; Steven R. J. Brueck and Gabriel P. Lopez
"Dual closed-loop, optoelectronic, auto-oscillatory detection circuit for monitoring fluorescence lifetime-based chemical sensors and biosensors", J. Biomed. Opt. 9(3), 609-617 (May 01, 2004). ; http://dx.doi.org/10.1117/1.1688814


Access This Article
Sign In to Access Full Content
Please Wait... Processing your request... Please Wait.
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
 
Your Session has timed out. Please sign back in to continue.
Sign In to Access Full Content

Tables

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement


Buy this article ($18 for members, $25 for non-members).
Sign In