RESUMO
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.
Assuntos
Técnicas Biossensoriais/métodos , DNA/metabolismo , Nanoestruturas/química , Condutividade Elétrica , Membranas Artificiais , Nanoestruturas/ultraestrutura , PorosidadeRESUMO
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.
Assuntos
Técnicas Biossensoriais/instrumentação , Condutometria/instrumentação , DNA/análise , DNA/química , Técnicas de Sonda Molecular/instrumentação , Nanoestruturas/química , DNA/genética , Desenho de Equipamento , Análise de Falha de Equipamento , PorosidadeRESUMO
It has been found possible to correlate chromatographic retention parameters directly with molecular electronic structure by means of a linear relationship. The empirical parameters used are total energy and localized charge, calculated by the method of Del Re. They are deduced directly from the molecular structure and they permit the retention index to be calculated theoretically with an acceptable error.