Well-ordered arrays of defects were prepared on a silicon
surface using a finely focused ion beam (FIB). The defects were
examined with a scanning force microscope (SFM) operated in the
tapping modeTM (TM-SFM). The
defects were holes with an estimated diameter of 50 nm, and the
spacing between individual defects was about 160 nm.
The surface was exposed to a solution of human serum albumin
(HSA) for two minutes, rinsed, dried, and studied with TM-SFM.
The images show that the rims of the defects were decorated with
HSA molecles, whereas the area between the defects was free from
This clearly demonstrates the high preferential adsorption of
albumin molecules to defect edges. Using FIB, surface defects can
be tailored with precision in order to obtain well ordered arrays
of proteins on surfaces, useful for applications like biosensors
and molecular memories. The marking of arrays enables the
possibility to study the same individual proteins and protein
clusters before and after interaction with other species of
molecules. As a first test, docking experiments will be performed
between site-selectively adsorbed HSA and different antibodies.
Anna Bergman, Division of Ion Physics, Uppsala University, Box
534, S-751 21 Uppsala, Sweden, ph: +46-18-183056, fax:
+46-18-555736, email: firstname.lastname@example.org