Title page for ETD etd-12152005-213148


Type of Document Dissertation
Author Zhang, Yan
URN etd-12152005-213148
Title Miniature fiber-optic multicavity Fabry-Perot interferometric biosensor
Degree PhD
Department Electrical and Computer Engineering
Advisory Committee
Advisor Name Title
Wang, Anbo Committee Chair
Heflin, James R. Committee Member
Jacobs, Ira Committee Member
Pickrell, Gary R. Committee Member
Safaai-Jazi, Ahmad Committee Member
Keywords
  • Temperature compensation
  • Polyelectrolyte self-assembly
  • Fiber optic biosensor
  • Fabry-Perot interferometry
Date of Defense 2005-12-06
Availability unrestricted
Abstract
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.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  dissertation.pdf 1.78 Mb 00:08:15 00:04:14 00:03:43 00:01:51 00:00:09

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.