Fabrication of Liquid-Crystal-Based Optical Sensing Platform for Detection of Hydrogen Peroxide and Blood Glucose.

Rapid and accurate determination of H2O2 is of great importance in practical applications. In this study, we demonstrate construction of liquid-crystal (LC)-based sensing platforms for sensitive and real-time detection of H2O2 with high accuracy for the first time. Single-stranded DNA (ssDNA) adsorbed onto the surface of nanoceria is released to the aqueous solution in the presence of H2O2, which disrupts arrangement of the self-assembled cationic surfactant monolayer decorated at the aqueous/LC interface. Thus, the orientation of LCs changes from a homeotropic to planar state, leading to change in the optical response from dark-to-bright appearance. As H2O2 can be produced during oxidation of glucose by glucose oxidase (GOx), detection of glucose is also fulfilled by employing the H2O2 sensing platform. Our system can detect H2O2 and glucose with concentrations as low as 28.9 nM and 0.52 μM, respectively. It shows high promise of using LC-based sensors for the detection of H2O2 and its relevant biomarkers in practical applications.