Stainless steel is used in a large
variety of food and medical
applications, where it is susceptible to adsorption of proteins and
other materials on its surface, ultimately leading to biofouling.
Here, we report the synthesis of a copolymer bearing both poly(ethylene
glycol) (PEG)-antifouling and phosphate-containing monomers, abbreviated
as poly(PEGMA-co-MEP), to be used as an easily applied
nano-coating for a stainless steel substrate. Highly tenacious films
could be easily deposited by dipping the stainless steel substrate
into a dilute aqueous solution of the polymer for a few minutes, which
then resisted rinsing over many days. This simple attachment method,
which does not need solvents, annealing, or adhesion promoters, looks
to be very easy transferable into commercial applications. From quartz
crystal microbalance with dissipation experiments, the films were
found only about one polymer layer thick. A variety of proteins and
skim milk were tested against the poly(PEGMA-co-MEP)-coated
surfaces, which showed almost a 100% reduction in binding affinity.
In addition, fluorescence microscopy results showed that PEG phosphate
and phosphonate-coated surfaces exhibited strong inhibition of bacterial
adhesion for both Escherichia coli and Bacillus cereus over several days. Other PEG polymers
containing carboxylic acids as anchoring groups were also tested and
gave a somewhat worse performance.