• atomic force microscopy;
  • fusion protein;
  • recombinant expression;
  • reflectometric interference spectroscopy;
  • surface plasmon resonance


Immobilization of biomolecules on solid surfaces is often combined with a partial loss of functionality. Therefore, smooth immobilization procedures are urgently required. Most recently, a Concanavalin A–Streptavidin (Con A–SAv) fusion protein was obtained, which allows the design of functionalized interfaces via self-assembling. The protein was successfully produced in Escherichia coli and the functionality was tested by surface plasmon resonance (SPR) measurements as well as by the mean of reflectometric interference spectroscopy. A re-generation of the mannan-coated surfaces, by washing with buffer containing 10% methyl α-D-mannopyranoside, could be demonstrated. This procedure should allow multiple measurements without replacing the chip. Investigation of the functionalized surfaces by atomic force microscopy showed a rather uniform coating with mannan and the fusion protein. In conclusion, the designed Con A–SAv fusion protein can be used as a universal linker between mannan-coated surfaces and biotinylated biomolecules, e.g. biotinylated antibodies.