The success of nanorobotics requires the precise placement and subsequent operation of specific nanomechanical devices at particular locations, thereby leading to a diversity of structural states. The structural programmability of DNA makes it a particularly attractive system for nanorobotics. A large number of DNA-based nanomechanical devices have been described, controlled by a variety of methods. These include pH changes and the addition of other molecular components, such as small molecule effectors, proteins and DNA strands. The most versatile of these devices are those that are controlled by DNA strands. This versatility results because they can be addressed specifically by strands with particular sequences. Researchers at New York University have developed a framework that contains a binding site – a cassette – that allows insertion of a rotary device into a specific site of a DNA array, allowing for the motion of a nanorobotic arm. Changing the cassette’s control sequences or insertion sequences allows the researchers to manipulate the array or insert it at different locations.
A large number of DNA-based nanomechanical devices have been described, controlled by a variety of methods: These include pH changes and the addition of other molecular components, such as small molecule effectors, proteins and DNA strands. The most versatile of these devices are those that are controlled by DNA strands: This versatility results because they can be addressed specifically by strands with particular sequences; these strands can be added to the solution directly, or perhaps they can result from another process ongoing within the local environment. Researchers have now shown that the state of a DNA-based nanomechanical device can be controlled by RNA strands, which means that nanomechanical devices could potentially be run from transcriptionally derived RNA molecules.
Recent developments in DNA-based nanotechnology have shown the suitability of this novel assembly method for constructing useful nanostructures. DNA molecules can serve as precisely controllable and programmable scaffolds for organizing functional nanomaterials in the design, fabrication, and characterization of nanometer scale electronic devices and sensors. DNA-templated metallic nanowires are such an example and over the past few years DNA scaffolds have been metallized with silver, gold, palladium, platinum and copper. DNA-based fabrication methods could ultimately lead to naturally bio-compatible nanodevices.
Researchers in South Korea used single-walled carbon nanotubes (SWNTs) to tag single-stranded DNA to locate a particular sequence of DNA within a complex genome. The results show that SWNTs may be used as generic nano-biomarkers for the precise detection of specific kinds of genes.
Researchers at the University of Illinois at Urbana-Champaign have shown that, by employing small pieces of DNA molecules called aptamers, nanomaterials can be smart enough to assemble or disassemble only in the presence of programmable signals such as AND or OR, with controllable cooperativity.
Setting a milestone towards fast DNA sequencing by a nanopore device, researchers developed a solid state nanopore device that can detect the difference between single molecules of double and single stranded DNA at high speed, with high accuracy, and at extreme pH. This research is a key step to develop a nanopore sequencing machine. More immediate application may be the sensing of long chain polymers for medical diagnostics.
A new approach promotes the use of zinc oxide nanomaterials as signal enhancing platforms for rapid, multiplexed, high-throughput, highly sensitive, DNA sensor arrays. Engineered nanoscale ZnO structures can be effectively used for the identification of the biothreat agent, Bacillus anthracis, by successfully discriminating its DNA sequence from other genetically related species.
French and U.S. researchers designed a nanomechanical DNA switch controlled by the rate of temperature variation, thereby providing a flexible, scalable alternative to simultaneous chemical control of different DNA switches at equilibrium.