Abstract
Nearly monodisperse glucose-sensitive poly[(N-isopropylacrylamide)-co-acrylamide-co-(phenylboronic acid)] microgels were synthesized in aqueous media by the functionalization of poly[(N-isopropylacrylamide)-co-acrylamide-co-(acrylic acid)] microgels with 3-aminophenylboronic acid via carbodiimide coupling. The glucose-sensitive and thermosensitive behaviour of the microgels was investigated using a dynamic light scattering technique. The introduction of the hydrophobic phenylboronic acid (PBA) group significantly decreases the temperature at which maximum volume change of the resultant microgel particles is observed. The glucose sensitivity of the PBA-containing microgels relies on the stabilization of the charged phenylborate ions by binding with glucose, which can convert more hydrophobic PBA groups to the hydrophilic phenylborate ions. The effect of pH, ionic strength and PBA content on temperature-induced volume change and glucose sensitivity was systemically studied. The effect of NaCl on the glucose sensitivity was also investigated at physiological pH and ionic strength. (C) 2011 Society of Chemical Industry