Abstract
We present the design, fabrication and optical investigation of photonic crystal (PhC) nanocavity drop filters for use as optical biosensors. The resonant cavity mode wavelength and Q-factor are studied as a function of the ambient refractive index and as a function of adsorbed proteins (bovine serum albumin) on the sensor surface. Experiments were performed by evanescent excitation of the cavity mode via a PhC waveguide. This in turn is coupled to a ridge waveguide that allows the introduction of a fluid flow cell on a chip. A response of ∂λ/∂c=(4.54±0.66)×105 nm/M is measured leading to a measured detection limit as good as fg or pg/mm2in the sensitive area.
Original language | English |
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Journal | Biosensors and Bioelectronics |
Volume | 24 |
Issue number | 12 |
Pages (from-to) | 3688-3692 |
ISSN | 0956-5663 |
DOIs | |
Publication status | Published - 2009 |
Keywords
- optical biosensor
- nanostructure
- photonic crystal
- silicon
- nanocavity