In-Plane Mode Resonant Cantilever Sensor to Detect Kinetic/Thermodynamic Parameters for Aptamer-Ligand Binding

An in-plane mode resonant cantilever sensor working in solution is developed for detecting physicochemical parameters of aptamer-ligand binding. The cantilever body is enclosed inside a hydrophobic parylene shell, and a ring-shaped hydrophobic slit is designed to prevent the solution leak inside the shell, allowing the cantilever structure keeps high-Q resonance in air while the binding sensing pool is exposed to aqueous solution for the biological binding. The resonant cantilever continuously records the frequency-shift according to the binding induced mass change on the cantilever. The frequency signal is useful for revealing kinetic/thermodynamic mechanism of the interface binding by fitting the detected sensorgram with classic equations. This detection strategy is label-free and calibration-free, with all the measurement completed using one device to avoid system error.