Microcantilever biosensors: Probing biomolecular interactions at the nanoscale

Microcantilever based biosensors have attracted much attention as a label-free, real-time and highly sensitive approach to the detection of biomolecules. When specific biomolecular interactions occur between a receptor immobilized on one side of a cantilever and a target analyte in solution, a mechanical bending of the cantilever results due to a change in surface stress, thereby translating biochemical interactions into a concentration-dependent nanomechanical response of the microcantilevers. In this review, we present a general overview of the operation principles, fabrication and preparation of microcantilever biosensors and discuss their uses for a wide range of biosensing applications. The focus of the review is given to probing the biomolecular interactions at the solid-liquid interface by measuring the cantilever bending. In addition to the label-free detection of DNA, protein and cells, the emphasis is also made to discuss about the new development of microcantilever biosensors for label-free probing nanoscale conformational changes of DNA, protein and polymers, and real-time detection of nanomechanical forces from living cells. Finally, the outlook for future development work and challenges is also discussed. © 2010 Bentham Science Publishers Ltd.