NIU’s C.T. Lin develops sensor
to detect poisons, chemical warfare agents

by Tom Parisi

NIU’s invention man is at it again.

Chemistry Professor C.T. Lin, who has eight patents to his name, unveiled his latest creation recently in San Francisco.

Lin has developed a sensor that selectively changes color immediately upon detection of a toxic chemical agent, including chemical warfare agents, such as nerve and mustard gas.

“The sensor is fast, very sensitive, agent selective and specific, durable and low cost,” Lin said. “As an added benefit, a decontamination catalyst can be encapsulated in the sensor.”

Lin’s device was one of 16 technologies featured in this past weekend’s Innovation Showcase at the 2007 International Meeting of the Association of University Technology Managers.

The technology takes advantage of the unique charge-transfer characteristics exhibited by various toxic agents. Mustard gas, for example, has a lone pair of electrons on the sulfur atom. This makes the toxin a good “electron donor,” Lin said.

The sensor contains an ideal reactive material that acts as an electron acceptor. When the sensor comes in contact with a toxin, it generates a color change through the flow of electrons from the donor to the acceptor by forming a charge-transfer complex. 

The sensor can be produced as a solid strip, array, film or coating. Lin said it could actually be spray-coated onto a uniform or piece of military equipment. In spray form, the sensor’s encapsulated catalysts could decontaminate an area, cleansing the air or surface area by speeding up the chemical reactions without creating toxic byproducts.

Lin has tested the sensor using non-toxic analogues, groups of chemical compounds similar in chemical structure but slightly different than their toxic cousins. The sensor was developed using sol-gel technology, converting nanocatalysts suspended in a liquid solution into a solid array that works as the sensor.

Sol-gel chemistry works at room temperature to produce optically transparent powders, array structures and ultra-thin coatings with a wide range of properties.

In addition to being useful for identifying chemical warfare agents, Lin’s technology can be adapted to detect other toxic agents, including heavy metals and agricultural pesticides and insecticides. Lin said it could potentially be used by Homeland Security, environmental agencies and waste management companies.

A professor who has won every top teaching and research award at NIU, Lin is never short on ideas for new technologies using the sol-gel process.

Among his creations:

• A thin film coating of specialized nanoparticles that act as “molecular fans” to cool nanodevices, such as the components found in advanced computers, high powered LEDs and cell phones.
• A conductive coating that acts as a shield to electromagnetic radiation generated by cell phones, high-tension wires and other electrical devices.
• An environmentally friendly metal-surface coating technology that eliminates the health, safety and waste disposal concerns of standard coatings for metals. The technology led to the creation of ChemNova Technologies, Inc., a university spin-off company that is marketing the process.

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