21 research outputs found
Differential attraction and repulsion of Staphylococcus aureus and Pseudomonas aeruginosa on molecularly smooth titanium films
Magnetron sputtering techniques were used to prepare molecularly smooth titanium thin films
possessing an average roughness between 0.18â
nm and 0.52â
nm over 5 ÎŒm Ă 5 ÎŒm AFM scanning
areas. Films with an average roughness of 0.52â
nm or lower were found to restrict the extent
of P. aeruginosa cell attachment, with less than 0.5% of all available cells being
retained on the surface. The attachment of S. aureus cells was also limited on films
with an average surface roughness of 0.52â
nm, however they exhibited a remarkable propensity
for attachment on the nano-smoother 0.18â
nm average surface roughness films, with the
attachment density being almost twice as great as that observed on the nano-rougher film.
The difference in attachment behaviour can be attributed to the difference in morphology of
the rod-shaped P. aeruginosa compared to the spherical S. aureus cells
An improved surface passivation method for single-molecule studies
We report a surface passivation method based on dichlorodimethylsilane (DDS)-Tween-20 for in vitro single-molecule studies, which, under the conditions tested here, more efficiently prevented nonspecific binding of biomolecules than the standard poly (ethylene glycol) surface. The DDS-Tween-20 surface was simple and inexpensive to prepare and did not perturb the behavior and activities of tethered biomolecules. It can also be used for single-molecule imaging in the presence of high concentrations of labeled species in solution.close