Understanding the mechanism and optimizing a competitive binding fluorescent glucose sensor

摘要

Our lab group is currently developing a fluorescent competitive binding assay between the Alexa fluor 647 labeled lectin, Concanavalin A, and highly structured glycosylated dendrimers to be sensitive to varying levels of glucose. Previously, this chemistry has elicited a high sensitivity to additions of physiological concentrations of glucose. However, the exact mechanism behind the sensing has not yet been well understood. This work presents a conceptual model of the response in which competitive binding results in different distributions of aggregates size to varying amounts of glucose. Preliminary experiments were performed by using Numerical Tracking Analysis (NTA) which correlates the movement of particles, positioned by light scattering, to the equivalent Brownian motion associated with particles of a certain spherical diameter. Using this method, the sensing chemistry was exposed to two different glucose concentrations and histograms of the size distribution for glucose concentrations were obtained. Herein the aggregation profile, mean aggregate size, and the number of aggregates (aggregates per mL) for two glucose concentrations are displayed, showing a correlation between the aggregation and glucose concentration.