California Institute of Technology

Jerry E Solomon

Scott E Fraser

Michael Roukes

Michael C Cross

Jessica L Arlett

A biofunctionalized nanoelectromechanical device (BioNEMS) for sensing single-molecules in solution by measuring the variation in the mechanical displacement of the BioNEMS device during a binding event is provided. The biofunctionalized nanoelectromechanical device according to the invention generally comprises a nanomechanical mechanical resonator, a detector integral with the mechanical resonator for measuring the mechanical displacement of the resonator, and electronics connected to the detector for communicating the results to a user. A system of biofunctionalized nanoelectromechanical devices and a method for utilizing the biofunctionalized nanoelectromechanical device of the present invention are also provided.

Active NEMS arrays for biochemical analyses

A bioNEMS device comprises a piezoresistive cantilever having flexing legs of which attach the cantilever to a support and a biofunctionalized portion at the tip. A bias current applied to the legs is limited by a maximal acceptable temperature increase at the biofunctionalized tip. The length of the cantilever has a magnitude chosen to minimize background Johnson noise. A catalyzed receptor on the device binds to a ligand whose binding rate coefficient is enhanced. The catalyst lowers the receptor-ligand binding activation energy and is designed by forced evolution to preferentially bind with the ligand. A carrier signal is injected by a magnetic film disposed on the cantilever which is electromagnetically coupled to a source of the carrier signal. A plurality of NEMS fluidicly coupled transducers generate a plurality of output signals from which a collective output signal is derived, either by averaging or thresholding. The NEMS devices are disposed in microfluidic flow channels and fabricated in a membrane. A linking molecule is attached to the tip of the transducer and a fluffball attached to the linking molecule to increase damping.

Dynamics bionems sensors and arrays of bionems sensor immersed in fluids

An outputs signal, v(t), is generated from a bioNEMs transducer and mixed with a reference signal and then filtered to generate a correlator output, r(t). The correlator output is detected to generate a signal u(t) and then determined whether the signal u(t) satisfies a predetermined threshold. If qualified, it is then decided whether the signal u(t) represents a predetermined type of interaction between a free ligand in a fluid in which the NEMS device is immersed and a receptor attached to the transducer. The threshold is the Neyman-Pearson criterion based on a predetermined probability of false detection, Pfa. The interaction may be binding of a free ligand to the receptor or releasing a bound ligand from the receptor by competitive binding with the free ligand. The step of detecting comprises detecting the envelope of the signal, r(t).

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Glendale, CA, United States of America

Jerry E Solomon