Bacterial Sunscreen: Layer-by-Layer Deposition of UV-Absorbing Polymers on Whole-Cell Biosensors (POSTPRINT)
AIR FORCE RESEARCH LAB TYNDALL AFB FL MATERIALS AND MANUFACTURING DIRECTORATE
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UV-protective coatings on live bacterial cells were created from the assembly of cationic and UV-absorbing anionic polyelectrolytes using layer-by-layer LbL methodology. A cationic polymer poly-allylamine and three different anionic polymers with varying absorbance in the UV range poly-vinyl sulfate, poly-4-styrenesulfonic acid, and humic acid were used to encapsulate E. coli cells expressing green fluorescent protein GFP either constituitively or through a theophylline-inducible riboswitch. Riboswitches are regulatory elements that activate gene expression after a ligand-RNA binding event hence, they operate as a cellular biosensor that will express a reporter protein after exposure to a ligand target. E. coli cells coated with polymers absorbing in the far UV range demonstrated enhanced protection to GFP stability, metabolic activity, and viability after prolonged exposure to radiation from a germicidal lamp. The results show the effectiveness of LbL coatings to provide enhanced protection to living cells for use in biosensor technology.
- Coatings, Colorants and Finishes