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Interview: Monitoring the environment
04 March 2010
Omowunmi Sadik talks to Keith Farrington about chemical sensors and nanotechnology in the environment
Omowunmi Sadik is a professor of chemistry at the State University of New York at Binghamton, US. Her research currently centres on interfacial molecular recognition processes, sensors and biomaterials, and immunochemistry with tandem instrumental techniques. Her work utilizes electrochemical and spectroscopic techniques to study human exposure assessment, endocrine disrupters, and toxicity of naturally occurring chemical compounds.
What inspired you to become a scientist?
My father was a pharmacist technician and he generally encouraged an interest in the sciences. In high school I was interested in physics, chemistry and biology and even though I loved history, the right direction seemed to be science. Most of my family followed similar scientific paths with three doctors and two nurses.
You're working at the boundary of materials and environmental chemistry. How do you feel this area has grown recently and what are its potential gains?
One general theme across these multiple areas is the concept of chemical and biological sensors. For instance chemically selective layers made up of polymers that are often used in sensors requires knowledge of the materials aspects. Then the polymers need to have properties that allow biologically active molecules to retain their activity. A transducer can be electrochemical or optically based and there also needs to be a form of signal processing. So sensors by their nature are multi-disciplinary and we have students developing skills across all of these disciplines to make sensors for a wide variety of applications
Tell us about some of your recent research
One of my recent projects was using microbial enzymes to convert highly toxic chromium (VI) to the non-toxic chromium (III). We had been using natural enzymes stable at low pH and it took 16 days and gave only 40% conversion. I had another student working on polymeric nanoparticles and it occurred to us to spike the broth with the nanoparticles to attempt to catalyse the conversion of the chromium. To our surprise the conversion increased to 98% within 5 minutes - a real eureka moment. It was very exciting. This paper was reported in the Journal of Environmental Monitoring and we have performed much follow on work on nanoreactors.
What do you think has been the high point of your career so far?
I had a project funded by the US Department of Defence that that was to make an ultra portable fluorescence capillary sensor (UPAC). The idea was to develop a bench top instrument into a portable sensor. It required knowledge of electronics and computer aspects and a lot of improvisation and innovation was necessary. A lot of my students liked to play with technology tools even though their backgrounds are in chemistry and biochemistry. It was great to see the projects evolve and also the students evolve too.
How do you think nanotechnology will impact on the environment?
There are many important applications of nanotechnology in the environment, such as in consumer electronics, personal products, bioimaging and remediation. I would like to see more positive applications of nanotechnology for environmental purposes, for example green nanotechnology and for improved energy efficiency. However, I also want to show that as with any new technology there are implications to consider. The potential negative aspects need to be identified. Are the nanomaterials toxic? What is the fate and transport of nanomaterials? where do they end up?
What areas would you like to see environmental scientists focus on in the future?
In the future I would like to see low cost, simple, more efficient and affordable. technologies that could impact on the third world. The most pressing area right now is global warming and impact of technologies and I would like to see more changes of policy backed by the sciences.
Omowunmi Sadik's homepage
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Foreword: JEM Spotlight: Environmental monitoring of airborne nanoparticles
Omowunmi (Wunmi) A. Sadik, J. Environ. Monit., 2009, 11, 1757
Sensors as tools for quantitation, nanotoxicity and nanomonitoring assessment of engineered nanomaterials
O. A. Sadik, A. L. Zhou, S. Kikandi, N. Du, Q. Wang and K. Varner, J. Environ. Monit., 2009, 11, 1782
Tuning the surfaces of palladium nanoparticles for the catalytic conversion of Cr(VI) to Cr(III)
Isaac O. KOwino, Marcells A. Omole and Omowunmi A. Sadik, J. Environ. Monit., 2007, 9, 657
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