By Will Soutter
Nanotechnology-Based Chemical Weapons
Nanosensors for Chemical Agents
Chemical and biological warfare has been banned by the international community. The unfortunate events of September 11, 2009, however, caused a major awakening in the US military - they realized that they may have to fight an enemy that does not always play by the rules. The USA, and many other countries around the world, have since begun funding the development of highly advanced military technologies to tackle potential chemical threats in the future.
The Defense Science Board recently compiled a study that marked nanotechnology as one among six technology areas with high potential. The Department of Defense (DoD) is one of the largest supporters of nanotechnology research - second only to the National Science Foundation. The DoD has allocated a significant budget towards funding research in magnetics, nanoelectronics, and nanomaterials for detection and protection against biological, chemical, explosive and radiological threats.
Nanotechnology could be used to create cheap, potent chemical agents which work even in very small volumes. However, nanosensors and nanocoatings could also help to defend soliders and the public from chemical and biological attacks. Image credit: Photos.com.
Nanotechnology-Based Chemical Weapons
It has been noted that many aspects of nanotechnology lend themselves to creating more powerful chemical weapons. Many of the supposed risks of nanotechnology are from far-future potential developments like "grey goo" nanobots, but there is also some risk from the technology we have access to today.
The main use of current nanotechnology in chemical weapons would be derived from the research into nano-enhanced drug delivery systems - by nanoformulating chemical agents to be absorbed by the body more readily, less potent chemicals could be used effectively. Lower volumes of toxic chemicals could also be used, removing the need for industrial-scale chemical production and opening up the possibility of attacks from parties with fewer resources, like terrorist cells.
At the current time, this sort of technology is still advanced, and largely in research or very early market stages, so free access to it is not available. Nanotechnology research and regulation should take these possiblities into account, however, to make sure that access to potentially harmful technology is safely restricted.
Using Nanotechnology to Combat Chemical Weapons
Types of chemical warfare agents include the following:
Nerve agents are especially dangerous as they attack the central nervous system; even minimal exposure will result in a quick and painful death. Present methods for detecting nerve agents are often ineffective in practice - for example, spectrophotometric techniques need non-aqueous solutions.
However, Jong Seung Kim, Jong Hwa Jung and coworkers in Korea have achieved a major breakthrough in using nanoparticles to make an effective system for the detection of nerve agents in water. A nerve agent receptor based on azo-pyridine was immobilized onto silica nanoparticles. The particles turn from yellow to red in a color change recognizable to the human eye on binding to the nerve agent mimic diethylchlorophosphate.
The nanoparticles do not just detect nerve agents but also destroy them. When they are treated with NaOH, the trapped toxins decompose to less harmful molecules and the nanoparticles are recycled and can be used again.
Nanosensors for Detection of Chemical Agents
Since the Gulf War, a trend that has become quite prevalent is to attempt to reduce the need for troop presence. To this end, tiny, lightweight, highly accurate nanosensors are being considered for deployment in combat. Small, mobile and economical sensors that can enable detection of enemy troop movements will enable commanders to have a comprehensive picture of the battlefield.
Nanosensors have the ability to sense the presence of single molecules of specific substances. Companies like Ibis Therapeutics and Cepheid are conducting research at the nano-scale to detect biological and chemical threats. Cepheid received a major grant from the army in 2003 to detect biothreats and other pathogens.
Chad Mirkin's Northwestern spinoff Nanosphere contracted with the U.S. Government Technical Support Working Group to use the proprietary biomolecular detection system of Nanosphere to detect biological warfare agents such as anthrax.
Charles Lieber's Harvard spinout Nanosys is looking to develop a nano-enabled sensor product within the next three years.
Researchers are also working on integrating nanosensors into lightweight and ultra-strong nanomaterials for future military uniforms at MIT's Institute of Solider Nanotechnologies.
The ISN received funding to develop a lethal, lightweight, completely integrated individual combat system. MIT is aiming at developing bullet-proof battle armor that cannot just filter out or reject toxins or chemical agents, it also weighs less than the usual 120 lbs of equipment.
Nanotechnology has a lot of advantages in terms of preventing biological and chemical attacks with effective sensors, and could give us the ability to effectively contain biological or chemical releases.
However, knowledge of nanotechnology developed by the chemical pharmaceutical industry to make more effective products could be used to make nanotechnology-based weapons which are easier to create, more deadly, and more insidious than conventional chemicla agents.
In the future, industry and political groups must consider initiating special training programs that are directed at helping future weapon inspectors becoming capable of identifying evolving and existing nanotechnologies that may be dangerous.