pH Dependent Lyotropic Liquid Crystal Characteristics for Optical pH Sensing at Nanoscales

Determination of hydrogen ion concentration is important in many metabolic interactions and physiological pathways. Nanotechnology has offered novel materials for pH sensing with applications in medical, biological, and pharmacological studies and in real-time monitoring of several biological interactions. A pH sensor platform can be used as an analytical tool for monitoring or diagnostic purposes, a drug delivery module for point-of-care therapy, or a combination of these modalities depending on the sensor's design and range of sensitivity. Lyotropic Liquid Crystal (LLC) nanostructures made of doped Monolinolein, a commercial food grade monoglyceride, with Linoleic Acid in aqueous conditions have shown exceptional properties as a pH dependent drug delivery system for therapeutic applications. This study aims to investigate the Raman pH dependent characteristics of these LLCs to demonstrate the capability of the matrices as dual-modality platforms for drug delivery and pH sensing at cellular interfaces. The study also explores release and load profiles of the LLCs per use of fluorescent dyes, as model guest drugs, to demonstrate the feasibility of these host systems in target delivery of fluorescent agents at biological sites. This approach can facilitate contrast enhanced imaging of biological interfaces which represent a pH gradient to their surroundings such as tumors.