Detection of glucose concentration using ion-exchange channel waveguide

An integrated sensor structure based on channel waveguide is constructed. The single-mode channel waveguide is prepared using 0.1% AgNO3–99.9% NaNO3 mixed molten salts under the condition that the diffusion coefficient can be assumed as constant. An experimental method is proposed and implemented to determine the equivalent diffusion coefficient and surface refractive index increment. The refractive index distribution of the channel waveguide is fitted and inferred. Ten glucose samples with different concentrations are tested at different wavelengths. The imaginary part of the propagation is determined by the Kramers–Kronig diversification. The correlation coefficient is designated as R2, and it is within the range of 0.9850–0.9961. The lowest detection limit of 0.1 μM is realized in the trace test.