Plasmon resonance microsensor for droplet analysis.
Microscale fiber tip sensors based on the plasmon resonance are reported. The fabrication process derived from our previous approach for manufacturing near-field scanning optical microscopy probes has been optimized for sensing applications. A typical tip sensor is a tapered fiber 400 microm in length, coated with a nanoporous thin silver film. The miniaturized geometry of the sensor allows detection in a single droplet of liquid solution (approximately 20 microl). The tip sensor is sensitive for refractive indices between 1.33 and 1.40 with a sensitivity of at least 3 x 10(-4) refractive index unit (RIU)/nm. The Raman scattering enhancement through these microsensors demonstrates the important role played by the localized plasmon resonance. The sensors' linear response covers a large region, interesting for biosensing in aqueous environments such as biomedical applications.
Chaigneau
M
M
Institut des Matériaux Jean Rouxel, UMR 6502, CNRS-Université de Nantes, BP 2229, 44322 Nantes, France. marc.chaigneau@cnrs-imn.fr
Balaa
K
K
Minea
T
T
Louarn
G
G
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods; D020349:Surface Plasmon Resonance / Q000379:methods; D013764:Tetrahydronaphthalenes / Q000032:analysis
D013764:Tetrahydronaphthalenes; D012834:Silver