An analyte in solution is made to react with a specific reactant coated on the wave-guide thus modifying the optical properties thereof. The index of refraction of the wave-guide material is higher than that of the reaction medium which ensures that a light signal injected into said guide be carried...http://www.google.com.au/patents/USRE33064?utm_source=gb-gplus-sharePatent USRE33064 - Method for the determination of species in solution with an optical wave-guide
