Development of selective fluorescent sensors for detection of biologically relevant analytes

Abstract

Fluorescent sensing has become an important tool in the detection and monitoring of biological materials. Specifically, fluorescent sensing has allowed us to make inroads into understanding the complex roles of proteins and peptides, as well as imaging cellular structures and tumors. Herein, we propose three small molecule fluorescent sensing platforms for the recognition of certain biologically relevant analytes. First, we developed a near-infrared (NIR), near-neutral cyanine dye for the detection of pH changes in vivo. Our results indicated our dye was able to detect changes in pH with a pKa in the near-neutral range. In addition, the dye was successfully encapsulated in red blood cells through low hemoglobin ghosting for in vivo measurement of pH with pKa values comparable to the in vitro studies. Second, we developed a small molecule coumarin-based fluorogenic probe for protein detection. As a proof of concept, we modeled this probe with a biotin-PEG3 moiety for detection of streptavidin. Our results indicated a preferential binding with significant changes in fluorescence compared to glycine (Gly), lysine (Lys) and bovine serum albumin (BSA).