상세정보

Spatiotemporal control of enzyme activity is important for many practical applications because it enables on-demand utilization of enzyme reactions, minimizing the dissipation/overdose of biocatalysis. This study reports enzyme-immobilized soft materials with amphibious adhesiveness demonstrate its potential for on-demand uses of enzyme reaction via simple attachment to a target surface. The asymmetric polydimethylsiloxane (PDMS) elastomer is consisted of intrinsic adhesion layer and porous structure layer. This porous layer of PDMS elastomer is used for the immobilization of glucose oxidase (GOx) via an approach of enzyme adsorption, precipitation and crosslinking (EAPC). The resulting crosslinked enzyme aggregates of GOx cover external surface as well as are embedded in the pores of PDMS elastomer. The presence of free chains in the adhesive layer enables stable and iterative attachment of PDMS elastomer on various solid surfaces under either dry or wet condition. As a proof-of-concept, effective killing of two model bacteria is demonstrated by underwater attachment of GOx-immobilized PDMS elastomer upon addition of glucose whose oxidation by EAPC of GOx generates hydrogen peroxide. Inherently adhesive and biocatalytically-active elastomer can be applied to various dry/wet surfaces, opening its great potential for on-demand use of biocatalytic reactions in a broad application, such as biomedical, environmental remediation, and packaging.

ABSTRACT i 
CONTENTS ii 
LIST OF FIGURES iv 
1. Introduction 1
 1.1. Regulation of Enzyme Activity On-Demand 1
 1.2. Amphibious Adhesive for On-Demand Application 2
 1.3. Precipitation-Based Enzyme Immobilization 3
 1.4. Microbial Decontamination 4
 1.5. Objective 5
2. Experimental Methods 7
 2.1. Materials 7
 2.2. Synthesis of Porous PDMS Adhesive 8
 2.3. Measurement of Mechanical Properties 9
 2.4. Immobilization of GOx into Porous PDMS Adhesive 10
 2.5. Activity and Stability Measurements of GOx 11
 2.6. Antibacterial Activity Assay 12
 2.7. Evaluation of Reactive Oxygen Species (ROS) 13
3. Results and Discussion 14
 3.1. Preparation and Performance of PDMS Adhesive 14
  3.1.1. Preparation of PDMS Adhesive 14
  3.1.2. Mechanical Characterization of PDMS Adhesive 16
 3.2. GOx-immobilized PDMS Adhesive 25
  3.2.1. Activity and Stability of GOx-Immobilized PDMS Adhesive 25
  3.2.1. Morphology of GOx-Immobilized PDMS Adhesive 31
 3.3. Antibacterial Applications of Biocatalytic Adhesive 38
4. Conclusions 46
REFERENCES 47