Designed Boronate Ligands for Glucose‐Selective Holographic Sensors

Abstract

In this study, 2-acrylamidophenylboronate (2-APB) was synthesised and its ability to bind with glucose was investigated both in solution and when integrated into a holographic sensor. Multiple forms of 2-APB, resulting from the neighbouring effect of the amido group with the boronic acid through an intramolecular B--O-coordinated interaction, were shown to exist in solution by using multinuclear NMR spectrometry. It was found that 2-APB predominantly adopts a zwitterionic tetrahedral form at physiological pH values. The complex formation of 2-APB with glucose and lactate was investigated in DMSO; 2-APB favours binding with glucose rather than lactate and generates a five-membered-ring complex. Furthermore, a 2-APB-based holographic sensor displayed a significant response to glucose with little interference from lactate, and with no dependence on pH in the physiological pH range. These features suggest that the new ligand 2-APB is a potential candidate for the development of glucose-selective sensors.

Complexation of L‐Lactate with Boronic Acids: A Solution and Holographic Analysis

“…[4] At pH 7.4 the three boronate receptors have been shown to adopt different conformations at the boron centre, [14,24] 3-and 4-APB are predominantly trigonal whereas 2-APB adopts a zwitterionic tetrahedral form. Previous studies have shown that 11 B NMR spectroscopy is a suitable analytical tool for the determination of boronate species, [20,23] and more information concerning the identity of boronate compounds can be obtained by employing this technique, rather than the traditional solution titration methods.…”

“…A plausible explanation is that in aqueous conditions 2-APB may self-associate to form a trimer that is dissociated on heating to 50 8C, releasing the hydroxyl groups that are then free to react with glucose (Scheme 1). It has also been observed [24] that there are very strong hydrogen bonds between the OH www.chemeurj.org groups of 2-APB, which may partly explain why 2-APB binds only weakly to glucose relative to the "trimer." However, further experimental studies are necessary to confirm which of these hypotheses is most probable.…”

Glucose‐Sensitive Hydrogel Optical Fibers Functionalized with Phenylboronic Acid

“…, (3-acrylamidopropyl)trimethylammonium) with PBA derivatives. [35] Alternatively, PBA derivatives such as 2-acrylamido-5-fluorophenylboronic acid, [8] 2-(acrylamido)phenylboronate, [36] 4-vinylphenylboronic acid (4-VPBA), [37] or their copolymerized combinations [38] can be used to improve the selectivity of the hydrogel fiber sensors to glucose. Electron-withdrawing substituents may increase the sensor response by decreasing the p K a of PBA.…”

Boronate affinity saccharide electrophoresis: A novel carbohydrate analysis tool

“…Boronic acids display differing binding affinities, independent of size/ charge ratios and for this quality boronic acid-functionalised gels have long since been utilised as a stationary phase for the analysis and separation of mono-, oligosaccharides and oligonucleosides by column chromatography [16]. Since boronic acids have been incorporated into hydrogels as sensors [17][18][19][20] they were the obvious choice of saccharide receptor for incorporation into electrophoresis gels. Electrophoresis gels are commonly a hydrogel assembled by copolymerising acrylamide (compound 1, Fig.…”