External cavity laser biosensor for label-free detection

optical biosensor;tunable laser

Zhang, Meng

关键词: optical biosensor;    tunable laser;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/78590/ZHANG-DISSERTATION-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

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.