Ultra Sensitive Monitoring of Analyte Concentrations Using Phase Sensitive Spectral Domain OCT

摘要

The refractive index is a basic optical property of a medium which is of great importance in physics, chemistry and most of biomedical applications. In our current study we monitor the change in refractive index for aqueous solutions of glucose, CaCl_2, MgCl_2, NaCl, KC1 and urea using a phase sensitive spectral domain optical coherence tomography (ph-SOCT) system. For instance, glucose induced changes in the phase are found to be 0.079 rad/mM in 200um thick cuvette for clear media and that is in good agreement with literature and our previous obtained data using phase sensitive low coherence optical reflectometry(PS-OLCR). The importance of this study is to demonstrate the capability of ph-SOCT to monitor ultra small changes in refractive index in clear media and the accuracy for glucose sensing is estimated to be ±2.6×10~(-6).