Aminophenylboronic acid polymer nanoparticles for quantitation of glucose and for insulin release

We have developed a simple route for the preparation of aminophenylboronic acid polymer nanoparticles (APB PNs) from 3-aminophenylboronic acid and formaldehyde under alkaline conditions according to an extended Stӧber method. Insulin and R6G have been selected to prepare functional insulin-APB PNs and R6G-APB PNs, respectively. During the formation of APB PNs, the representative molecules are embedded inside the APB PNs. Through specific binding of glucose with boronic acid moieties on the R6G-APB PNs and insulin-APB PNs, glucose induces expansion of the APB PNs, leading to release of R6G and insulin molecules, respectively. As a result of release of R6G molecules, the fluorescence intensity of R6G-APB PN solution increases, allowing quantitation of glucose in PBS solutions (10 mM, pH 7.4) with a linear range over 0–10 mM. Release of insulin from insulin-APB PNs is significant and rapid when the glucose concentration is higher than 7 mM. Having advantages of low cost, simple preparation, biocompatibility, and continuous response to glucose, the insulin-APB PNs hold great potential as an alternative for treating diabetic patients. [Figure not available: see fulltext.]