Copolymerization of N-acryloyl-m-aminophenylboronic acid (NAAPBA) with acrylamide
(AAm) on the surface of glass plates resulted in the formation of a hydrogel film with porous
structure and capable of optical response to the changes in concentration of glucose in
the contacting solution. The boronate specific dye, Alizarin Red S (ARS) was incorporated
into hydrogel film to increase the sensitivity towards glucose and poly(N-vinylpyrrolidone)
(PVP) was incorporated to prevent the dye leakage. The obtained boronate-containing
polymer film responded to submicromolar concentration of glucose with optical density
changes being a linear function of glucose concentration in the range from 0.1 to 1 mM.
The PVP–ARS-containing gel exhibited a 10-fold higher glucose sensitivity compared with
the colorless NAAPBA-AAm gel. The equilibrium dissociation constants of soluble ARS–PVP
and ARS-NAAPBA-containing copolymer complexes at pH 7.3 were found to be 1.4 and
0.44 lM, respectively. The low dissociation constants enabled the preparation of the sensor
with increased operational stability of at least two months allowing more than 20 assays of
with no loss in the sensitivity or dye leakage
