Abstract
A novel type of intelligent microcapsule reactor system was prepared. This reactor can recognize pH change in the media and control reaction rate by itself. For the reactor system, acrylic acid (AA), N-isopropylacrylamide (NIPAM), and glucose oxidase (GOD) were selected as a pH-responsive device, a gating device and a reaction device, respectively. Poly(NIPAM-co-AA) (P-NIPAM-co-AA) is known to change its hydrophilicity-hydrophobicity due to pH change. They were integrated in a core-shell microcapsule. GOD was loaded inside the core space and the pores in the outside shell layer were filled with P-NIPAM-co-AA linear grafted chains as pH-responsive gates by plasma graft filling polymerization method. At high pH value, the P-NIPAM-co-AA gates are hydrophilic and the microcapsule permits glucose penetration into the core space and GOD reaction proceeds. On the other hand, at low pH value, the P-NIPAM-co-AA gates are hydrophobic and the microcapsule prevents glucose penetration, resulting no GOD reaction. The accuracy of this concept was examined.
