Instant Detector Devised

Commercializing a new type of detector that can instantly identify biochemical contaminants in liquid is the objective of Gene (Guenadi) Rabinski, a Canadian physicist, and David Mathine, an optical scientist with the University of Arizona.

Rabinski, president of scientific consulting firm R&D Innovative Solutions Inc. and an adjunct professor of physics at the University of Ottawa, has been well known to the Canadian scientific community, especially in Ottawa, for innovations and patents he developed for JDS Uniphase Corp. (now JDSU), a major provider of broadband test and measurement solutions and optical products.

Mathine joined the faculty of the College of Optical Sciences at the University of Arizona (UA) in 1996; he was formerly a faculty associate at Arizona State University, in Tempe, involved with the integration ov VCSELs (vertical-cavity surface-emitting lasers), MESFETs (metal-semiconductor field effect transistors) and photodiodes with CMOS circuitry.

His current interests involve the development of a biochip for toxicity testing of chemicals, a high-bandwidth electro-optic modulator, a microphotonic integration with CMOS circuitry and the development of electro-optic eyeglasses. Previously, he was a device engineer at Rockwell International, where he helped develop MCT (mercury cadmium telluride) infrared focal plane arrays integrated with silicon circuitry.

Rabinski's master's degree in physics from Russian State University (1983) was issued in Moscow, and his thesis subject was "Electromagnetic emission of biological objects," which he said was "quite unique in the former USSR." He received a PhD in physics in 1991 from the Earth Sciences Institute in Kiev, where he developed electro-optomechanical instrumentation for in-situ underground analysis of mining samples.

COS-7 cells integrated on a custom CMOS chip. COS-7 cells are derived from African green monkey kidney cells. The cells were stained with DAPI (a fluorescent stain that binds strongly to DNA) and imaged under a fluorescent microscope. (Image: David Mathine)

Mathine received BS and MS degrees in electrical engineering from the University of Nebraska-Lincoln (in 1981 and 1983, respectively) and a PhD in electrical engineering from Purdue University in 1991. His thesis work involved the optical study of materials by spectroscopic ellipsometry, and his dissertation work involved the MBE growth and material characterization of the wide gap II-VI selinides and tellurides as well as the III-V antimonides and arsenides.

The two met at Photonics North, sponsored by the Canadian Photonics Consortium, in June in Ottawa. Their backgrounds and scientific approaches are different, but complementary: Mathine is involved in the detection of chemical contamination, and Rabinski is focusing on biological contamination.

Mathine said he had realized the potential for an "instant" detector as a result of his work on a microchip that will instantly test the toxicity of chemicals to animals and humans without the need to formally test them on animals.

The ability to concurrently test liquids for chemical and biological contamination is a logical next step, the researchers agree.

Mathine's biological sensors are based on optical, electrical, chemical and capacitance. "These sensors are using custom CMOS electronics and integrating live cells directly on the microchips," he said.

The work is being developed through a collaboration with Joseph J. Bahl of the Sarver Heart Center and Raymond Runyan of Cell Biology and Anatomy, both at the University of Arizona. It is being sponsored by the Semicondcutor Research Corp. (SRC) through the Engineering Research Center for Environmentally Benign Semiconductor Processing at UA.

"Detecting toxins is critical to many areas, such as pharmacology, toxicology and environmental monitoring," Mathine said. "One method for toxin detection is the use of a cell-based biosensor." By using living cells, cell physiology can be monitored to screen for toxicity and provides an alternative to live-animal testing.

Mathine added, "Currently, many chemicals are not tested for toxicity because of the sheer number of new chemicals that are developed every year. The goal of this work is to screen these chemicals and identify toxic or potentially toxic chemicals before they are moved to a manufacturing line and find their way into the environment."

Rabinski was offered an opportunity to join a new venture and to lead research and development of instrumentation for in-situ detection of dangerous bacteria in potable water after a 2000 outbreak of E. coli O157:H7 infection in southern Ontario, Canada, that claimed 7 lives and hospitalized several others. The following year, he invented a method of digital optical measurement of particle populations using reduced magnification that was patented in the US (with minor modifications).

"The invention became a breakthrough technology," Rabinski said. The instrumentation based on the invention is currently sold in the US, the UK, Canada, China, Japan, South Korea and Taiwan. It is capable of in-situ detection of certain signs of the presence of dangerous bacteria in water, rather then in-situ direct detection of bacteria. He has also been a valuable contributor to a strategic environmental program on lake sediment supported by the Canadian Government (http://www.science.uottawa.ca/lsse).

"Standard commercially available methods of bacteria detection usually involve sampling water, growing bacteria culture and analyzing the bacteria colonies," Rabinski said. "A typical process of analysis of bacteria in water usually takes two to three days -- which is way too long, taking into consideration the magnitude of natural and intentionally introduced threats."

"Detection of chemical contamination of water, which is a totally different field than biological contamination of water, usually takes much less time, he said. "Nevertheless, there are serious holes in this field as well, especially when concentration of dangerous chemicals is low, or when certain dangerous chemicals were intentionally introduced to water."

Since many types of dangerous bacteria may reside in drinking water and there are different bacterial life forms (i.e., spores), in-situ detection of dangerous bacteria in water is an extremely complex problem, Rabinski said. Since 2003, he has focused on in-situ detection of biological contamination. He was able to develop the entirely new technology so that it is capable of not only in-situ detection of the threat of dangerous bacteria in water, but also of addressing the cleanliness and biological safety of medical reusable invasive instruments, such as endoscopes. (The technology is far superior to, and is not based on, the digital optical measurement invention mentioned previously.)

A scientific technology proof study has been completed with support and auditing of the National Research Council Canada which "shows that it works," Rabinski said.

R&D Innovative Solutions Inc. is looking for investment sources to commercialize the technology for use in water, medical and some other applications, and for collaborators in the areas of chemistry, biochemistry and microbiology to further advance it.

For more information, visit: www.dgrsol.com. Rabinski can be reached at drrabinski@dgrsol.com.