Abstract: The possible use of nanopores for single DNA molecules biosensing has been demonstrated, but much remains to do in order to develop advanced engineered devices with enhanced stability, and controlled geometry and surface properties. Here we present morphological and electrical characterization of solid state silicon nitride nanopores fabricated by focused ion beam direct milling and chemically functionalized by probe oligonucleotides, with the final aim of developing a versatile tool for biosensing and gene expression profiling.
Abstract: We present data concerning the electrical properties of a class of biosensor devices based on
bio-functionalized solid state nanopores able to detect different kinds of interactions between
probe molecules, chemically attached to the pore surface, and target molecules present in
solution and electrophoretically drawn through the nanometric channel. The great potentiality
of this approach resides in the fact that the functionalization of a quite large pore (up to
50–60 nm) allows a sufficient diameter reduction for the attainment of a single molecule
sensing dimension and selective activation, without the need for further material deposition,
such as metal or oxides, or localized surface modification. The results indicate that it will be
possible, in the near future, to conceive and design devices for parallel analysis of biological
samples made of arrays of nanopores differently functionalized, fabricated by standard
lithographic techniques, with important applications in the field of molecular diagnosis.
Abstract: The use of biological “nanopores” as sensors for single molecules like DNA was recently demonstrated: the passage of the molecules through the pore separating two electrolyte-filled reservoirs is induced by a voltage application and detected as a current drop. Present attention is devoted to solid state nanopores, with obvious advantages, such as high stability, control of diameter, adjustable surface properties and the potential for integration into complex devices. We present results on DNA-functionalized solid state nanopore devices produced by using a Focused Ion Beam, to obtain an high throughput platform for gene expression profiling, that is for the rapid molecular diagnosis of tumours and other genetic diseases.
Abstract: We report the description af a new low cost method to create a device based on a chemically modified nanopore created on a polymeric membrane. Using Soft-Lithography and Nanofabrication it can be possible to create a nanopore on a free standing polymeric membrane. After oligonucleotide functionalization of the lumen of the nanopore it is possible to detect specific sequences of DNA, thanks to the hybridization properties of the double helix. The sensing principle is based on transient interruptions in the ion-current induced by entry, transport and exit of a particular analyte from the pore.
Abstract: Recently, nanopore technology has been introduced for genome analysis. Here we show results related to the possibility of preparing "engineered solid state nanopores". The nanopores were fabricated on a suspended Si3N4 membrane by Focused Ion Beam (FIB) drilling and chemically functionalized in order to covalently bind oligonucleoticles (probes) on their surface. Our data show the stable effect of DNA attachment on the ionic current measured through the nanopore, making it possible to conceive and develop a selective biosensor for gene expression profiling. (c) 2008 Elsevier Ltd. All rights reserved.
