Cantilever-based sensing: the origin of surface stress and optimization strategies.
Many interactions drive the adsorption of molecules on surfaces, all of which can result in a measurable change in surface stress. This article compares the contributions of various possible interactions to the overall induced surface stress for cantilever-based sensing applications. The surface stress resulting from adsorption-induced changes in the electronic density of the underlying surface is up to 2-4 orders of magnitude larger than that resulting from intermolecular electrostatic or Lennard-Jones interactions. We reveal that the surface stress associated with the formation of high quality alkanethiol self-assembled monolayers on gold surfaces is independent of the molecular chain length, supporting our theoretical findings. This provides a foundation for the development of new strategies for increasing the sensitivity of cantilever-based sensors for various applications.
Godin
Michel
M
Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada. mgodin@uottawa.ca
Tabard-Cossa
Vincent
V
Miyahara
Yoichi
Y
Monga
Tanya
T
Williams
P J
PJ
Beaulieu
L Y
LY
Bruce Lennox
R
R
Grutter
Peter
P