Optical Characterization of the Antigen–Antibody Thin Layer Using the Whispering Gallery Mode Optical Characterization of the Antigen–Antibody Thin Layer Using the Whispering Gallery Mode
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We immobilized an antibody (anti-β-Galactosidase) on a polystyrene microsphere by using a covalent bond, and observed the resonance peaks in the scattered light intensity spectra related to the whispering gallery mode (WGM) excitation of the microsphere. The amount and the optical parameters, <i>i.e.</i>, thickness and refractive index, of anti-β-Galactosidase on the sphere surface were evaluated based on an absorbance measurement and a resonance peak shift measurement, respectively. Moreover, we measured the variation of the WGM spectra depending on the concentration of the enzyme solution (β-Galactosidase), which allowed us to optically evaluate the thickness and the refractive index of the antigen–antibody layer from the shift of the WGM spectra peak.
- Analytical Sciences
Analytical Sciences 30(8), 799-804, 2014
The Japan Society for Analytical Chemistry