Saccharide Sensing Based on Saccharide‐Induced Conformational Changes in Fluorescent Boronic Acid Polymers

Abstract

Summary: A novel fluorometric saccharide detection strategy has been established by utilizing saccharide‐induced conformational changes in copolymers containing boronic acid and fluorescent units. The polymer chain changes its conformation due to an alteration of the charge state induced by binding with saccharides. The conformational changes are conveniently detected by monitoring excimer to monomer intensity ratio in the fluorescence spectra. Thus, the present strategy would be a promising way for the creation of highly selective and sensitive saccharide‐sensing systems.Saccharide‐induced conformational change in copolymers containing boronic acid units.magnified imageSaccharide‐induced conformational change in copolymers containing boronic acid units.

Responsive Boronic Acid-Decorated (Co)polymers: From Glucose Sensors to Autonomous Drug Delivery

“…The reverse system is possible when a cationically charge comonomer is incorporated into the responsive gel, showing the spectrum of isolated pyrene moieties in the absence of saccharides. The electrostatic interaction with the formed charged boronate esters upon diol addition promotes the formation of pyrene excimers, which showed the most sensitive result with charged diols like calcium-glucarate [92]. This final system where the boronate ester formation promotes excimer formation has also been reported by Yam et al based on a positively charged trimethylpentylammonium pyrene salt that is forced to interact through electrostatic interactions with the negatively charged boronate esters (Figure 10, left).…”

Boronic acid-modified thin film interface for specific binding of glycated hemoglobin (HbA1c) and electrochemical biosensing

“…This property was employed to confirm the presence of functionalized boronic acid on the electrode surface. We selected d-fructose as the model binding sugar because it is known to bind to phenylboronic acid more strongly than any other monosaccharide [35]. In this experiment, pH 9 PBS was chosen as the alkaline condition, and pH 7 was selected as the neutral (control) condition.…”

Thin semitransparent gels containing phenylboronic acid: porosity, optical response and permeability for sugars

“…Binding of sugars to the pendent groups of PBA results in enhanced hydration and conformational changes in the soluble polymers (Kanekiyo et al, 2005) as well as in swelling of the PBA-containing hydrogels (Kikuchi et al, 1996;Gabai et al, 2001;Asher et al, 2003;Lee et al, 2004). Due to the formation of anionic boronate-sugar complexes, significant difference appears between the concentrations of ions in the gels and the surrounding solution.…”

“…This has led to several studies of polymer hydrogels and thin polymeric films containing phenylboronic acid (PBA) as possible sugar sensors (Kikuchi et al, 1996;Gabai et al, 2001;Asher et al, 2003;Lee et al, 2004). Polymers containing PBA as a pendant group are known to interact with sugars, polysaccharides and nucleic acids in aqueous media Uguzdogan et al, 2003;Kanekiyo et al, 2005;Liu and Scouten, 2005;Kuzimenkova et al, 2006). For the physico-chemical reasons discussed below, it was difficult to obtain a linear response of dimensional or electrical characteristics of the gels to sugar concentration.…”