Testing Multiple Stimulus-Responsive Hydrogel Films with Catalytic Functions Polymerized by Enzymatic Initiation: An Undergraduate Laboratory Experiment for Designing a Visual Biomolecular Logic System

Visual biomolecular logic systems can bridge biology, chemistry and electronics, foster interdisciplinary thinking among students and enhance their understanding of modern chemical applications. In this paper, an innovative undergraduate laboratory experiment was reported, which enabled senior undergraduate students to prepare enzyme-containing hydrogel films using a green and mild method of enzyme-initiated radical polymerization. In particular, the enzyme could maintain its catalytic activity in the films and play an important role in the mimicking of biologic gates. The first part of this experiment includes the synthesis and characterization of diallyl viologen (DAV) monomers; the preparation and characterization of hydrogel poly( N, N -diethylacrylamide-DAV)-glucose oxidase (defined as P(DEA-DAV)-GOD) films; and the testing of the multiple stimulus-responsive properties of the hydrogel films toward external stimulations, such as potential, excitation light, temperature, and glucose (i.e., the substrate of the enzyme GOD). The second part involves the construction of visual Boolean biomolecular logic gates and logic devices for realizing bioinformation processing, such as encoders, decoders and molecular keypad locks for information encryption/decryption. By highlighting the principles of sustainable green chemistry, this comprehensive laboratory experiment combines enzymatic catalytic polymerization, multiple stimulus-responsive hydrogels, and molecular logic gates for information encryption, demonstrating significant interdisciplinary teaching value in polymer science, analytical chemistry, physical chemistry, biochemistry, and electronics.