In an effort to detect biological threats quickly and accurately, a number of detection technologies have been developed. This rapid growth and development in biodetection technology has largely been driven by the emergence of new and deadly infectious diseases and the realization of biological warfare as new means of terrorism. To address the need for portable, multiplex biodetection systems a number of immunoassays have been developed. An immunoassay is a biochemical test that measures the level of a substance in a biological liquid. The assay takes advantage of the specific binding of an antigen to its antibody, the proteins that the body produces to directly attack, or direct the immune system to attack, cells that have been infected by viruses, bacteria and other intruders. Physical, chemical and optical properties that can be tuned to detect a particular bioagent are key to microbead-based immunoassay sensing systems. A unique spectral signature or fingerprint can be tied to each type of bead. Beads can be joined with antibodies to specific biowarfare agents. A recently developed novel biosensing platform uses engineered nanowires as an alternative substrate for immunoassays. Nanowires built from sub-micrometer layers of different metals, including gold, silver and nickel, are able to act as "barcodes" for detecting a variety of pathogens, such as anthrax, smallpox, ricin and botulinum toxin. The approach could simultaneously identify multiple pathogens via their unique fluorescent characteristics.
As their name suggests, nerve agents attack the nervous system of the human body. All such agents function the same way: by interrupting the breakdown of the neurotransmitters that signal muscles to contract, preventing them from relaxing. Nerve agents, depending on their purity, are clear and colorless or slightly colored liquids and may have no odor or a faint, sweetish smell. They evaporate at various rates and are denser than air, so they accumulate in low areas. Nerve agents include tabun(GA), sarin(GB), soman(GD), and VX. The military has a number of devices to detect nerve agent vapor and liquid. Current methods to detect nerve agents include surface acoustic wave (SAW) sensors, conducting polymer arrays, vector machines, and the most simple, color change paper sensors. Most of these systems have have certain limitations including low sensitivity and slow response times. By using readily synthesized network films of single-walled carbon nanotube bundles researchers have built a sensor capable of detecting G-series nerve agents such as Soman and Sarin (Sarin was used in the Tokyo subway terrorist attack in 1995). This research opens new opportunities in the design of real-time chemical warfare agent (CWA) sensors with independent response signatures.
Due to the the increased use of modern bombs in terrorist attacks worldwide, where the amount of metal used is becoming very small, the development of a new approach capable of rapidly and cost-efficiently detecting volatile chemical emission from explosives is highly desirable and urgently necessary nowadays. The trained dogs and physical methods such as gas chromatography coupled to a mass spectrometer, nuclear quadrupole resonance, electron capture detection as well as electrochemical approaches are highly sensitive and selective, but some of these techniques are expensive and others are not easily fielded in a small, low-power package. As a complementary method, however, chemical sensors provide new approaches to the rapid detection of ultra-trace analytes from explosives, and can be easily incorporated into inexpensive and portable microelectronic devices. Researchers in PR China have developed a nanocomposite film that shows very fast fluorescence response to trace vapors of explosives such as TNT, DNT or NB.
Carbon nanotubes (CNTs) have great potential applications in making ballistic-resistance materials. The remarkable properties of CNTs makes them an ideal candidate for reinforcing polymers and other materials, and could lead to applications such as bullet-proof vests as light as a T-shirt, shields, and explosion-proof blankets. For these applications, thinner, lighter, and flexible materials with superior dynamic mechanical properties are required. A new study by researchers in Australia explores the energy absorption capacity of a single-walled carbon nanotube under a ballistic impact. The result offers a useful guideline for using CNTs as a reinforcing phase of materials to make devices to prevent from ballistic penetration or high speed impact.
All major powers are making efforts to research and develop nanotechnology- based materials and systems for military use. Asian and European countries, with the exception of Sweden (Swedish Defence Nanotechnology Programme), do not run dedicated programs for defense nanotechnology research. Rather, they integrate several nanotechnology- related projects within their traditional defense-research structures, e.g., as materials research, electronic devices research, or bio-chemical protection research. Not so the U.S. military. Stressing continued technological superiority as its main strategic advantage, it is determined to exploit nanotechnology for future military use and it certainly wants to be No. 1 in this area. The U.S. Department of Defense (DoD) is a major investor, spending well over 30% of all federal investment dollars in nanotechnology. Of the $352m spent on nanotech by the DoD in 2005, $1m, or roughly 0.25%, went into research dealing with potential health and environmental risks. In 2006, estimated DoD nanotechnology expenditures will be $436m - but the risk-related research stays at $1m.
Anthrax is an acute infectious disease caused by the bacteria Bacillus anthracis and is highly lethal in some forms. Anthrax spores can and have been used in biological warfare. "Weaponizing" the spores requires a process to make an aerosol form of anthrax so that they easily can enter the lungs. Inhalation is the most lethal form of anthrax infection. Consequently there has been significant interest in the surface structure and characteristics of anthrax spores as related to their binding by molecular species. The investigation of such binding is obviously important to the development of countermeasure technologies for the detection and decontamination of anthrax spores. A group of researchers at Clemson University have come up with an agent that clings to the anthrax spores to make their inhalation into the lungs difficult.
The just released 2007 National Nanotechnology Initiative (NNI) budget request is $1.28 billion, slightly less than the 2006 estimated spend of $1.30 billion. The 2007 numbers would bring the overall NNI investment since its inception in 2001 to $6.6 billion. The lion share of this amount, $2 billion or 30.3%, went to the Department of Defense (DoD). In 2006, the DoD's share even reached 33.5% of the entire NNI budget.
Researchers in Singapore functionalized a polymer nanofiber membrane to capture chemical warfare agents such as nerve agents. The nanofibers in the membrane act as a substrate on which the nerve agents get physically adsorbed followed by chemical decomposition.