Table 1.
Parameters | Sensing modes | ||
---|---|---|---|
Dynamic | Static | ||
Sensing principle |
Measurement of change in resonant frequency due to change in mass and/or spring constant Measurement of resonant frequency due to change in surface stress |
Measurement of cantilever displacement due to change in surface stress | |
Features |
Receptors are immobilized on either one side or both sides of the cantilever Sensitivity can be improved by operating the cantilever at higher modes |
Receptors are immobilized on one side of the cantilever Sensitivity can be improved by incorporating stress concentration regions |
|
Limitations |
Erroneous due to adsorbate-induced changes in stiffness Susceptible to fluid damping effect Susceptible to material damping effect Dependence of change in resonant frequency on position of the target molecule on the cantilever |
Structural nonlinearity due to large deflection of the cantilever Dependence of surface stress generation on immobilization protocols |
|
Suitability for measurement | Liquid | Low | High |
Air | High | High | |
Resolution | Mass: 10−24 g [74] | Cantilever deflection: 4Å [87] |