Nanocantilever biosensors detect multiple genes

Sep 19 2006

Using nanoscale cantilevers in a microfluidics device, a team of European researchers has developed a portable biosensor capable of detecting specific genetic sequences.

Such a device could be used to detect the presence of cancer-associated genetic changes at a patient’s bedside or in a physician’s office. This work has been published in the journal Sensors and Actuators B: Chemical.

Laura Lechuga, Ph.D., of the Spanish Microelectronics National Center, headed the team that developed this new sensor, which integrates 20 nanocantilevers, 20 surface emitting lasers, and light-sensing circuitry within a single microfluidics device. Each nanocantilever is coated with a short nucleic acid sequence that is complementary to a target gene, and each cantilever is irradiated by its own laser.

When a solution containing that gene flows over the cantilever, the gene binds to nucleic acid, causing the cantilever to bend slightly in much the same way that a diving board bends in response to someone walking onto it. As each cantilever bends in response to binding to its specific nucleic acid sequence, the direction of the light reflecting off the cantilever changes. This change is detected by an integrated optical detector, creating an electrical signal. The researchers constructed the entire device on a silicon wafer using standard lithographic techniques and note that it is capable of real-time monitoring of multiple gene-binding events.

This work is detailed in a paper titled, “A highly sensitive microsystem based on nanomechanical biosensors for genomics applications.” Investigators from the Biotechnology National Center of Spain, the University of Southampton, in the UK, the French Centre National de la Recherche Scientifique (CNRS), and Genetrix, in Madrid, also participated in this study. This paper was published online in advance of print publication. An abstract of this paper is available at the journal’s website. View abstract.