Preparation and responsive behaviors of chitosan-functionalized nanoparticles via a boronic acid-related reaction.

We presented here a facile strategy for constructing chitosan-functionalized nanoparticles through the coordinating interaction between phenylboronic acids in poly(3-methacrylamido phenylboronic acid) and amine groups in chitosan. The formation of nanoparticles was confirmed by Fourier transform infrared spectrometer, thermal analysis, dynamic light scattering, and transmission electron micrographs, and the nanoparticles were stable over three days in aqueous solution. The pH-sensitivity of the nanoparticles was revealed by the light scattering intensity ratio (I/I0) at different pH values. I/I0 kept constant at pH 7.0 and 8.0. When the pH value was further increased in the range of 8.0-10, I/I0 reduced. As the pH value increased above 10, I/I0 kept constant. The nanoparticles were also sensitive to glucose, and the glucose-responsive behavior was dependent on the pH values, nanoparticle concentrations, and nanoparticle compositions.