Optomechanical damping of a microcantilever force sensor in liquid

摘要: A new instrument, constant deflection atomic force microscopy (CD-AFM) constructed to perform spectroscopy measurements without mechanical instabilities associated with the use of soft AFM cantilevers has been developed, tested and calibrated. One major limitations in is cantilever instabilities. This includes thermodynamic noise non-equilibrium close surface. limitation can obscure ultrahigh resolution short range measurements, limits accessible dynamic range. More stable stiff have poor resolution. The softest standard limited by improved from approximately 30 pN ~2 using CD-AFM system. It was proved that discontinuity distance curve surface, 7 nm, prevented CD-AFM. The kept even after jumps Using CD-AFM, inaccessible regions near surface be explored valuable information about very tip-surface interactions studied. The need lock prevents signal record interactions. Alternatively, laser used keep employed curves obtained were scaled a method introduced for this purpose. calibration tested, validated through electrostatic conventional or showing same behavior. Application unfold five concatamer protein immunoglobulin 27 showed wider than AFM. For example, loading rate stiffness pulling speed. increases but degenerating resolution. Moreover, L shows no refolding event due tension loaded on refolded recoil. recoil removed events become observable.