Bio-NanoMechanical Cantilever Force Sensor for Disease Diagnosis

Disease diagnosis through simultaneous detection of multiple analytes requires sensitive biosensing tools capable of transducing molecular interactions into some physical quantity. A microdiagnostic kit based on arrays of microcantilevers with self-sensing capability is proposed in this study for the purpose of disease diagnosis. Microcantilever-based detection technique equipped with piezoactive read-out device enables transduction of molecular recognition into a nanomechanical motion which enables diagnosis through detection of a great number of analyte simultaneously in a single step. The proposed mechanism offers a variety of advantages over other detection techniques including low cost, simplicity, high sensitivity, low sample consumption, and non-sample preparation requirement. Arrays of gold coated microcantilevers including a reference cantilever are functionalized through enzymes, antibodies or other receptors. A set of valves and a microsyringe pump is used to bring the sample solution containing protein biomarkers into contact with respective cantilevers. Molecular binding that takes place over cantilever surface induces differential surface stress. The nanomechanical movement as a result of the induced surface stress would be a good source of the amount of concentration of protein biomarkers in the sample solution. Applying the proposed mechanism, a novel biosensor can be implemented for continuous monitoring of glucose concentration in blood. A comprehensive modeling of the system is obtained which relates the output voltage of the system to nanomechanical movement of cantilever. For sensitivity enhancement, we are proposing to extend this study and design to nanocanilevers or depositing nanoparticles over cantilever surface which increases surface area thus capturing higher number of proteins.