Benzoboroxole-modified nanoparticles for the recognition of glucose at neutral pH
Benzoboroxole modified nanoparticles were prepared starting from a polystyrene-covinylbenzylchloride latex by nucleophilic substitution with 6-amino-1-hydroxy-2,1-benzoxaborolane. It is known that benzoboroxole binds to saccharides at pH 7.4 due to the intramolecular coordination of a hydroxyl group coordinating as a donor group, which compensates the electron deficiency of the boron. These benzoboroxole modified nanoparticles were tested with regard to their aqueous saccharide binding ability utilizing Alizarin Red S as a reporter dye. Consequently, the pH value was chosen to be 7.4 as the targeted key feature. It was shown that the binding of fructose as well as glucose can be determined by UV-Vis spectroscopy in a concentration range from 20 mM to 400 mM which is of clinical relevance. The binding constants determined by the analysis of competitive binding for the benzoboroxole modified nanoparticles were 2354 M-1 for fructose and 580 M-1 for glucose. Furthermore, the temperature stability up to 121 °C of these nanoparticles was tested and it could be shown that 95% of the initial binding capacity could be conserved.