SGER: Single Molecule-Radiation Interaction in Whispering-Gallery Mode Evanescent Field

NATIONAL SCIENCE FOUNDATION

ABSTRACT

Proposal Number: CTS-0541585

Principal Investigator: Guo, Zhixiong

Affiliation: Rutgers University

Proposal Title: SGER: Single Molecule-Radiation Interaction in Whispering Gallery Mode Evanescent Field

The proposal was received as an unsolicited submission to the Chemical and Transport Systems Division in the Small Grants for Exploratory Research (SGER) category and was subsequently assigned to the Thermal Transport and Thermal Processing Sub-element of the Thermal Systems Program. The objective of this project is to understand how the interactions of single molecules with the evanescent radiation field affect the whispering-gallery mode (WGM) microresonances such that WGM-based optical sensors can be explored as a new tool for molecular probing. The project objectives will be to simulate the detection of single proteins and protein-protein interactions using the proposed WGM microresonant sensor. Recent advances in nanofabrication have made it feasible to consider optical resonances in fine and uniform microcavities having physical dimensions at the micro/nanometer levels. Such devices enable a wide array of ultra-sensitive and compactly integrated sensor technologies. This exploratory project will examine and demonstrate the feasibility, capability and sensitivity of label-free detection of single biomolecules and molecular interactions using WGM microsensors. If successful, this exploratory work would lead to advances that may lead to the development of practical devices that are sensitive, selective, and stable with rapid response time. In addition to proteins, other examples of ligands that can be immobilized on the WGM sensor include antibodies to sense the presence of specific antigens, DNA for capture through hydridization, or enzymes/receptors for the detection of specific substrates/ligands. The potential applications to food safety analysis and detection of low levels of chemicals and toxins would contribute to the nation's general strategy in combating bio-terrorism. The research will impact the education of graduate students and undergraduate students who will participate in the project. The participation of students in research offers them the opportunities to expand their intellectual horizon to interdisciplinary research and promotes the training of engineering students to prepare for the high-technology workforce. The research results will be widely disseminated in professional journals, and national and international conferences and benefit the community and society at large.