A microscale biosensor based on integration of sigle-stranded DNAs and aligned multi-walled carbon nanotubes

This paper reports the design and fabrication of a biosensor based on aligned side-wall functionalized multiwalled carbon nanotubes with integrated single-strand DNAs (ssDNA). Due to their direction dependent physical properties and size, electrically conducting multi-wall carbon nanotubes (MWCNTs) with attached complementary ssDNA show promise to function as next-generation nanoscale sensors for numerous biosensing diagnostic applications. Hybridization kinetics between complementary and target ssDNA nucleotide base pairs results in a local charge generation between base pairs that is injected into the MWCNTs resulting in a change in MWCNT electrical characteristics. With the integration of ssDNA to the exterior surface of MWCNTs the possibility of fabricating a real-time biosensor that operates on a combination of change in electrical properties and nucleic acid testing (NAT) principles can be realized