Attachment of Escherichia coli to poly(dimethylsiloxane) irradiated at 254 nm.

摘要

The purpose of this research was to determine a method to attach Escherichia coli to poly(dimethylsiloxane) irradiated at 254 nm. By determining a method for attachment, it can be used to pattern the E. coli cells which can ultimately be used for creation of biosensors or for bacterial studies. For attachment, an E. coli culture was grown in M9 media to an optical density of 0.5 -- 0.7, and 10 mL of culture was poured into a Falcon(TM) tube. The irradiated PDMS was placed in the cell culture for one hour, removed, rinsed with deionized water, and dried with nitrogen. It was determined that the most bacterial attachment occurred at a pH of 2. The amount of irradiation time was also varied, but it was determined that there was roughly the same amount of attachment at all irradiation times. There was a pH dependence on the attachment of E. coli to native PDMS with attachment only seen at an acidic pH. Also, ATR-FTIR was performed on samples placed in media at different pH and different forms of M9 media, but the spectra showed either the native PDMS spectra or spectra of irradiated PDMS with a slight decrease in the carbonyl peak. To verify that carboxylic acids were present on the surface before and after being placed in media a methylene blue experiment was performed. The data showed that carboxylic acids were present. It is theorized that the E. coli are attaching to the native and irradiated PDMS via an electrostatic interaction.