Direct calibration of colloidal probe cantilevers via Derjaguin, Landau, Verwey, and Overbeek surface forces in electrolyte solution

The development of colloidal probe microscopy has made it possible to directly measure the interaction forces between two different surfaces in solution. Cantilever calibration is presently a subject of intense experimental and theoretical interest due to the need for accurate force measurement. We developed a novel and direct calibration method for colloidal probe cantilevers to which a silica microsphere has been previously attached based on fitting experimental force curves for the interaction between the silica sphere and a silica flat in dilute KBr solutions to the theoretical Derjaguin, Landau, Verwey, and Overbeek force curves using the measured zeta potential of the silica surfaces.