A highly sensitive microsystem based on nanomechanical biosensors for genomics applications

Abstract

Microcantilever-based biosensors are a promising tool to detect biomolecular interactions in a direct way with high accuracy. We show the development of a portable biosensor microsystem able to detect nucleic acid hybridization with high sensitivity. The microsystem comprises an array of 20 micromechanical cantilevers produced in silicon technology, a polymer microfluidic system for delivery of the samples, an array of 20 vertical cavity surface emitting lasers (VCSELs) with collimated beams thanks to an integrated microlens array, an optical coupling element to provide the optical path required, and chips with the photodetectors and the CMOS circuitry for signal acquisition and conditioning, capable of measuring the cantilever deflection with sub-nanometer resolution. Robust immobilization and regeneration procedures have been implemented for the oligonucleotide receptor sequences. In a further innovation, an optical waveguide cantilever transducer has been also developed in order to improve the final performance of the device. This has a number of advantages in terms of a simple optical geometry and improved sensitivity.

Electrical properties of polysilicon nanowires for device applications

“…They are currently attracting much attention as components for future nanoelectronic devices such as nanowire field effect transistors [1], photonic and optoelectronic devices [2], and as chemical or biological sensors [3,4]. SiNWs present large advantages with respect to bulk silicon: high surface to volume ratio, possibility of surface functionalization, synthesis compatible with large area technology, leading to the development of innovative electronic devices.…”

Existing Biosensing Platforms for the Nucleotide Markers Detection

“…The cantilever for AFM typically is a probe in the form of a needle grown from a strong inorganic material at the end of the foldaway beam. The cantilevers can be effectively used to study chemical processes that occur upon binding of specific molecules on their surface that allows one to create highly sensitive biosensors on their basis that can detect, for example, the NA-analyte without the use of reporter groups [81][82][83][84][85][86]. The general principle of operation of the sensor, in this case, can be represented as follows.…”

Collective Micro-Optics Technologies for VCSEL Photonic Integration

“…As for emerging applications such as sensing, VCSEL beam generally propagates in free space and its beam waist has to be precisely controlled to fit the detection area, at distances from few hundred of µms [5,6] to several centimeters [7]. Consequently, major requirements concern beam collimation with divergences of ∼1…”