Novel Preparation Method for Obtaining pH-Responsive Core−Shell Microcapsule Reactors

We have developed a new procedure using the plasma-graft polymerization method to investigate the preparation of core−shell enzyme-loaded microcapsule reactors with environment-responsive membranes. The conventional methods used to prepare this type of microcapsule lead to the deactivation of enzymes; therefore, we employed a novel preparation method to prevent any loss of enzymatic activity. First, core−shell microcapsules were prepared by combining a Shirasu porous glass membrane emulsification step and an interfacial polymerization step. The “bottle-in” method was used to load the microcapsules with glucose oxidase, and the “plasma-graft polymerization” method was used to fill in the pores of the shell membranes with a copolymer of N -isopropylacrylamide and acrylic acid to achieve a pH-responsive gating function. The plasma operation in this step was conducted on the enzyme-loaded microcapsules, and this formed environment-responsive gates while maintaining the enzymatic activity. These microcapsule reactors were composed of a porous shell membrane that had a pH-responsive gating function that controlled the rate of reaction occurring in the core, and this pH-responsive reactivity was achieved by the gating function's ability to recognize the pH of the medium from the change in diffusivity of the pH-responsive polymer gates at different pHs.