Nanomechanical Sensor Array for Detection of Biomolecular Bindings: Toward a Label-Free Clinical Assay for Serum Tumor Markers

A label-free technique capable of rapidly screening human blood samples simultaneously for multiple serum tumor markers would enable accurate and cost-effective diagnosis of cancer before physiological symptoms appear. Recently, microfabricated, bimaterial cantilever sensors have been demonstrated to detect DNA hybridization and antigen-antibody binding at clinically relevant concentrations. Cantilever sensors deflect measurably under the surface stress resulting when biomolecules immobilized on one surface of the sensor interact with their binding partners [1]. We present an array of cantilever sensors (silicon nitride with a gold coated surface) capable of simultaneously interrogating 100 different biomolecular interactions.