Abstract
A 30-mm-long multimode waveguide, 40 μm wide and 40 μm high, is fabricated on a silicon wafer using polymer SU-8 as the core and liquid buffer as the cladding. Antibodies are successfully immobilized on the SU-8 surface designated for binding target antigens dispersed in the buffer solution. Evanescent-wave spectroscopy is performed by exciting the fluorescently labeled antigens, bound to the waveguide surface within its evanescence field, and measuring the emission light intensity. This evanescent-wave biosensor detects specific molecular interaction. The optical output as a function of the antigen concentration can be described by Langmuir equation. Antigen concentration as low as 1.5 μg/mL is detected; concentrations higher than 100 μg/mL lead to sensor saturation. [2008-0058].
Original language | English (US) |
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Pages (from-to) | 1495-1500 |
Number of pages | 6 |
Journal | Journal of Microelectromechanical Systems |
Volume | 17 |
Issue number | 6 |
DOIs | |
State | Published - 2008 |
Keywords
- Antibody immobilization
- Biomolecule binding
- Evanescent wave
- SU-8 waveguide
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering