122nd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Material Chemists
Room No. Room 322
Time THU 09:49-:
Code MAT.O-8
Subject Fruit browning mimetic protective coating for extreme environment endurance at the biological interface
Authors Hong Park, Seonki Hong1,*, Haeshin Lee2,*
Department of Chemistry, Korea Advanced Institute of Science and Technology, Canada
1Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science & Technology, Korea
2Department of Chemistry, Korea Advanced Institute of Science and Technology, Korea
Abstract For a living organism, maintaining stability between the internal environment and the external environment is an important factor for survival. Therefore, the surface of an organism acts as a barrier that is usually satisfactory for most external environments, but extreme environments such as vacuum space can cause these natural barriers to be insufficient. We propose a fruit browning chemistry mimetic protective coating at the biological interface to be able to withstand extreme environment. The coating is achieved by the aerobic oxidation of the pyrogallol (PG) moiety, which is abundantly found in plant polyphenol derivatives that result fruit browning on air-exposed surface. In our study, enzyme-mediated aerobic oxidation of pyrogallol in fruit browning process was successfully replaced to pH-induced aerobic oxidation followed by Michael-type reaction with the amine-rich polymer, polyethylenimine (PEI). We applied this coating to the surface of various soft matters such as hydrogels, polymeric microbeads, plant leaves, and soft tissues for electron microscopic imaging. The coating protected these soft matters from dehydration and thermal melting in ultra-high vacuum condition with the electron beam exposure in the scanning electron microscopy (SEM). Surprisingly, dehydration protection makes the surface conductive, so the metal sputtering process, which is mandatory for organic specimens for SEM imaging, was not needed. Therefore, fruit browning mimetic coating allows simple and rapid analysis of biological specimens without conventional multiple sample preparation steps (e.g., dehydration in gradient ethanol solutions and metal sputtering).
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