Surface plasmon resonance for gas detection and biosensing☆
Abstract
Surface plasmon resonance is a new optical technique in the field of chemical sensing. Under proper conditions the reflectivity of a thin metal film is extremely sensitive to optical variations in the medium on one side of it. This is due to the fact that surface plasmons are sensitive probes of the boundary conditions. The effect can be utilized in many ways. A description of how it can be used for gas detection is given, together with results from exploratory experiments with relevance to biosensing.
References (3)
- A. Kindlund et al.
Physical studies of quartz crystal sorption detectors
Sensors and Actuators
(1982)
Cited by (2187)
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Based on a Paper presented at Solid-State Transducers 83, Delft, The Netherlands May 31 - June 3, 1983.