Poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) microgel was synthesized by precipitation polymerization.Poly(N-isopropylacrylamide-co-3-acrylamidophenylboronic acid) (P(NIPAM-co-AAPBA)) microgel was obtained by the modification of P(NIPAM-co-AA) microgel with 3-aminophenylbornic acid under 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) catalysis.Almost complete conversion of the carboxylic groups in P(NIPAM-co-AA) microgel was confirmed by the disappearance of the peak at 1711 cm-1 in FTIR spectra.Both microgels are thermosensitive

however

the volume phase transition temperature of P(NIPAM-co-AAPBA) microgel is much lower than that of P(NIPAM-co-AA) microgel

as a result of the introduction of hydrophobic phenylboronic acid groups.The P(NIPAM-co-AAPBA) microgel exhibits good glucose-sensitivity

as its size increases with increasing glucose concentration.The increasing glucose concentration also results in a decrease in the turbidity of the microgel dispersion

which makes it possible to trace the kinetics of the glucose-induced swelling by turbidity.The kinetic curves were fitted with single-exponential function and the corresponding characteristic swelling times were obtained.The time required for the system to reach swelling equilibrium is on the magnitude of 102 s.The swelling rate increases with increasing glucose concentration.Compared with the macroscopic hydrogel with same composition

the glucose-induced swelling of P(NIPAM-co-AAPBA) microgel is much faster.However

compared with the swelling of PNIPAM microgels induced by temperature

the glucose-induced swelling is much slower.