Subra Muralidharan Targets “Agents of Terror”  
by: Francis C. Assisi

Boston, 06 November -- In this time of war and terror, Dr. Subra Muralidharan and his research group are helping to usher in a technological revolution from their laboratory at Western Michigan University’s Haenicke Science Hall.

Specifically this Indian American scientist is a leading researcher in nanobioenvironmental chemistry. The goal: to help in the creation of an early warning system for biological, chemical, and radiological terrorism.

Muralidharan and his group are pioneers in nanotechnology, a field that combines chemistry, physics, biology, and engineering together to investigate the interactions, reactions, organization, and construction of materials the size of atoms and molecules. “When the particles of a material become smaller and smaller, scientists can no longer use classical mechanics to observe its properties,” explains Muralidharan. Many nanoparticles contain interesting sensing capabilities that have useful environmental and biological applications.

That’s why a new grant from the U.S. Department of Energy put $2 million in new funding into WMU’s nanotechnology research last month for research towards improving national security. The grant will support two years of continued research on a project that focuses on "Design, Synthesis and Characterization of Nanosensors for Chemical, Biological and Radiological Agents."

The initiative, which began last year with a $950,000 grant from DOE, is directed by Muralidharan, who heads WMUs Nanotechnology Research and Computation Center.

The new funding will be used to continue development of nanosensors that could be used to detect chemical, biological and radiological weapons deployed against civilian populations or in military situations. They could include particles released by a "dirty bomb" or deadly nerve toxins such as sarin.

If successful, Muralidharan says, such sensors could be embedded in uniform fabric or the paint on military vehicles. When exposed to the substance they were designed to detect, the sensors could alert either an individual or a central control center.

The challenges come, he says, from trying to design the nanosensors so that they can detect very small quantities of what he calls "agents of terror" in vast open areas, in water systems and in groundwater. At the same time, they must be capable of adapting to changing temperature and humidity levels as well as wind, dust and other environmental factors. The nanosensors must be able to capture, concentrate and measure the levels of the target toxins and provide a signal that is measurable, such as a digital or audio signal or a change in color.

"These are formidable challenges, but nanosensors have much greater potential for meeting them than conventional approaches," Muralidharan says. "Were grateful for the opportunity to develop this technology."

According to Muralidharan, WMU has been researching nanotechnology for several years now. With a grant from the Department of Energy, WMU is currently working to develop artificial molecules that remove harmful radioactive nuclei from nuclear rays. Radioactive nuclei are harmful to humans because of the radiation they give off. The molecules that WMU is researching to develop would break down these radioactive nuclei.

Muralidharan is clearly using the new developments in nanotechnology to help national security systems.

"This could be extended to a number of different things regarding security, such as the biological and chemical warfare agents," Muralidharan said. "What if we think about an early warning system based on these materials. Something that would generate a signal and say there may be gas or anthrax or radioactive nuclei. Radioactive materials are also weapons of terrorists."

"Were not just talking about specific material for a specific task; its an idea for a whole program which would be developing nanosensors for sensing and destroying any target agents of terror," Muralidharan said.

"We are optimistic that in about four to five years we should have products that have a commercial application," said Muralidharan

Besides nanosensors for the detection of chemical (example: sarin, VX), biological (example: anthrax, small pox), and radiological (example: plutonium) agents of terror for homeland security applications, Muralidharan’s research involves other critical areas in nanotechnology. For example, use of nano prostaglandin biosensors for selective detection and diagnostics, self-assembling molecules for the recognition of radioactive nuclides, microfluidic devices capable of separations and synthesis in picoliter and nanoliter volumes, and synthesis of novel nanomolecules for detection of viruses.

Finally, Muralidharan is involved in fundamental investigations of the toxicity of Nanoparticles. Because the dimensions of the nanoparticles is smaller than that of the cell in human beings and other organisms, a natural question that arises is whether the nanoparticles can penetrate the cell membrane, enter the cell, and disrupt cell functions.

For this he has developed a portable “lab on a chip” to instantaneously perform a complex sequence of tasks that normally would have to be performed in a laboratory. The chip will contain nanoparticles that will separate, synthesize, and perform high throughput screening of molecules in extremely small volumes—capabilities that will greatly improve work in forensics, diagnostics, drug discovery, and environmental science.

Now, Muralidharan and his team are extending this “lab on a chip” into a “lab on a CD.” Whereas the “lab on a chip” is stationary and requires a clean, homogeneous sample, the “lab on a CD” will have the advantage of a spinning chip. “The centrifugal field resulting from spinning chips at a very high speed will allow the separation and analysis of even complex nonhomogeneous mixtures,” he explains.

The Xerox Corporation has also joined the nanotech revolution, having enlisted the help of Muralidharan and his research team to develop more robust nanophotoreceptors for imaging. To this end, the corporation has given WMU $60,000 to support a graduate student’s work in chemistry over a three-year period. Muralidharan has also submitted a larger grant proposal to the National Science Foundation for further support. “The development of nano-photoreceptors will impact the imaging industry in general,” he explains.

Muralidharan stresses the impact the nanotechnology revolution will have on our lives and our understanding of the physical world. “Until recently, our knowledge of materials has been based on/how large systems behave,” he says. “The real excitement of nanotechnology is that we now have anew paradigm to change the way we learn about the world through science. And because nanoscienceand nanotechnology are truly multidisciplinary, the way we do research and the way we teach will change.”

Many of us will see this impact within our lifetimes, Muralidharan predicts. “We are taking these principles and turning them into reality. It will happen sooner than we think.”

Muralidharan obtained his B.S (1972) and M.S. (1974) from the University of Madras, before earning his Ph.D. (1979) from the University of Notre Dame.

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