Good as Gold

Dr. Chusuei
Dr. Charles Chusuei

Dr. Charles Chusuei’s technology could transform patient care in emergency rooms and health centers worldwide

As with most scientific research, discoveries with big applications often boil down to thinking small. Really small. Yet it also involves the detection of some- thing one can find a bottle of in almost every home—hydrogen peroxide. It turns out that bubbling stalwart of home-based healthcare is also a natural byproduct of the biochemistry of all living organisms. The ability to monitor hydrogen peroxide on a molecular level has a host of practical applications in fields as diverse as healthcare (early cancer detection) and food service (spoilage detection).

As a result, researchers have developed
a variety of nanotech-based sensors. For the most part, those technologies have used sensors dependent on carbon nano- tubes (CNT) coated with oxides derived from precious metals—gold, palladium, ruthenium, etc. As the word “precious” suggests, it’s not cheap to use such metals.

Dr. Chusuei found that the expensive way to do things was hardly the only way. In an effort to establish a cheaper biosensing material, Chusuei turned to zinc. An earth-rich element, zinc is much more abundant and, therefore, cheaper than the precious set. But in order to establish it as a viable substitute, Chusuei and his team first needed to control the shape of the ZnO compound itself. (The more complete the coverage by the ZnO of the CNT, the better the sensor.)

“It was a lot like the fairy tale ‘Goldilocks and the Three Bears,’” Chusuei says. In the end, working the ZnO into its ideal shape required many things being “just right.” It required, among other things, finding just the right temperature (90 degrees Celsius) and pH (7.365) of the solution in which the suspended nanoparticles were formed as well as establishing just the right amount of time for sonication (the application of sound energy to agitate the solution).

With the bulk of the research completed—and with the right balance struck—it’s actually a rather simple procedure to replicate, but as Chusuei’s patent application shows, it wasn’t an obvious one. The real-world potential of the research has Chusuei and his students excited. The cheaper the materials, the more widespread the possible application of the technology.

Cancer is not the only affliction potentially addressed by the research
of Chusuei and his students, nor is hydrogen peroxide the only substance detectable. Another vein of inquiry includes the detection of lactic acid, a marker for anaerobic respiration (the presence of which can indicate that a patient is not breathing well or getting enough oxygen). Such sensors could detect signs of physical distress that show up well “before changes in heart rate
or blood pressure would be registered,” Chusuei points out.


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