Quantitative spectrum analysis of nanoparticle embedded contact lens for tear glucose monitoring

Abstract

Glucose level is a primary indicator in the diagnosis and treatment of diabetes mellitus. According to the correlation between glucose concentration in blood and tears, measuring tear glucose is an alternative to traditional strips test for blood glucose. Thus, measuring glucose levels in tears could provide noninvasive monitoring of blood glucose. As a biocompatible sensor of biomarker, a glucose dependent color changing contact lens is developed with embedded nanoparticles composed of glucose oxidase and cerium oxide (III). Using spectroscopy, we found the detectable changes in reflection spectrum of contact lenses with respect to the glucose concentration, and developed correlation curve of the reflection spectrum with known glucose level. Additionally, we performed the comparison study with image analysis to estimate how accurate our device to configure the color of nanoparticle embedded contact lens. From the comparison, we found the possibility of application spectrometer to color detection. Based on the knowledge, we applied our system to clinical tear sample. Furthermore, we assessed tear glucose level and correlated with blood glucose level from the diabetic mice model to evaluate this algorithm. Our algorithms for regular monitoring of glucose using contact lens biosensor may lead to noninvasive monitoring of tear glucose level.