External cavity laser biosensor for label-free detection

Optical label-free biosensors serve as a powerful detection tool to analyze biomolecular interactions, and have been widely used in pharmaceutical drug discovery and biochemical sensing. Desirable performance metrics for such sensors include high sensitivity and fine resolution, which are essential for achieving high-precision detection of small molecules. In this work, we demonstrate a dual-mode external cavity laser (ECL) biosensor to address the desired needs. The utilization of photonic crystal resonant reflector biosensor as mode-selection filter enables high sensitivity, while the stimulated emission process in the laser cavity provides high spectral resolution. Additionally, dual-mode operation of the ECL system enables a self- referencing technique which significantly improves the signal to noise ratio. This advanced instrument enables direct detection of small molecule binding to immobilized protein targets, which is essential for drug discovery process. We develop a plasmonic ECL to further improve the performance metrics of ECL biosensors. Utilizing surface plasmon resonance (SPR) biosensor as mode-selection filter, the plasmonic ECL demonstrates 3× higher sensitivity than photonic crystal based ECL biosensor. Moreover, compared to that of traditional SPR biosensors, the quality factor of the plasmonic laser biosensor is significantly enhanced, improving the spectral resolution. The enhanced biosensing capability of the plasmonic ECL offers unique opportunity for detecting biologically important molecules and viral particles in extremely low concentration.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Zhang, Meng

Contributors dc:contributor

• Cunningham, Brian T.
• Cooper, Lance
• Eden, Gary J.
• Hergenrother, Paul J.

• optical biosensor
• tunable laser

Statement dc:rights

• Copyright 2015 Meng Zhang

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/78590

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/78590