Miniature fiber-optic multicavity Fabry-Perot interferometric biosensor

Fiber-optic Fabry-Perot interferometric (FFPI) sensors have been widely used due to their high sensitivity, ease of fabrication, miniature size, and capability for multiplexing. However, direct measurement of self-assembled thin films, receptor immobilization process or biological reaction is limited in the FFPI technique due to the difficulty of forming Fabry-Perot cavities by the thin film itself. Novel methods are needed to provide an accurate and reliable measurement for monitoring the thin-film growth in the nanometer range and under various conditions. In this work, two types of fiber-optic multicavity Fabry-Perot interferometric (MFPI) sensors with built-in temperature compensation were designed and fabricated for thin-film measurement, with applications in chemical and biological sensing. Both the tubing-based MFPI sensor and microgap MFPI sensor provide simple, yet high performance solutions for thin-film sensing. The temperature dependence of the sensing cavity is compensated by extracting the temperature information from a second multiplexed cavity. This provides the opportunity to examine the thin-film characteristics under different environment temperatures. To demonstrate the potential of this structure for practical applications, immunosensors were fabricated and tested using these structures. Self-assembled polyelectrolytes served as a precursor film for immobilization of antibodies to ensure they retain their biological activity. This not only provides a convenient method for protein immobilization but also presents the possibility of increasing the binding capacity and sensitivity by incorporating multilayers of antibodies into polyelectrolyte layers. The steady-state measurement demonstrated the surface concentration and binding ratio of the immunoreaction. Analysis of the kinetic binding profile provided a fast and effective way to measure antigen concentration. Monitoring the immunoreaction between commercially available immunoglobulin G (IgG) and anti-IgG demonstrated the feasibility of using the MFPI sensing system for immunosensing applications.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Electrical and Computer Engineering

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2005

Author dc:creator

• Zhang, Yan

Chair dc:contributor.committeechair

• Wang, Anbo

Committee members dc:contributor.committeemember

• Heflin, James R.
• Jacobs, Ira
• Safaai-Jazi, Ahmad
• Pickrell, Gary R.

• Temperature compensation
• Polyelectrolyte self-assembly
• Fiber optic biosensor
• Fabry-Perot interferometry

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-12152005-213148

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/30104