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Omowunmi A. Sadik

Dr. Omowunmi A. Sadik

Professor of Bioanalytical and Environmental Chemistry

  • Ph.D., University of Wollongong, Australia
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Research Interests:

A core objective of my research program is to understand the mechanisms of how chemical information is transformed from one interface to another, and to use that knowledge to develop innovative sensing technologies, functional materials and devices. We are conducting groundbreaking research in biosensors towards the development of new diagnostic tools and detection devices for various medical, environmental and food applications.

My group and I have authored or co-authored over 160 scientific publications and I have given over 350 invited lectures and conference contributions world-wide. Some of my publications have appeared in very reputable scientific journals such as ACS Nano, RSC Advances, Langmuir, ACS Catalysis, Chemical Communications and Biosensors & Bioelectronics. We have 5 US patents and have successfully translated basic research in biosensors into the design and fabrication of a prototype portable, fully autonomous, and remotely operated sensing device known as U-PAC™ (Ultra-Sensitive Portable Capillary Sensor). My laboratory has discovered a new class of nanostructured, π-conjugated, poly (amic) acid - PAA. The uniqueness of PAA lies in its excellent chromatic, electronic, biodegradable and mechanical properties. We have focused on continued efforts ultimately aimed at small molecule-driven molecular design and preparation of sustainable nanomaterials with precise tuning of electrochromatic properties on demand. The materials provide superior properties which can meet the requirements of society’s expectations for a safer environment and sustainable future.

The concept of sustainable nanotechnology involves the nanoscale control of synthesis and processing of matter without footprints that give rise to environmental degradation. Hence there is a search for synthetic methods that utilize fewer amounts of materials, water, and energy; while reducing or replacing the need for organic solvents. Our group has developed anisotropic nanoparticles using water soluble, naturally-derived flavonoids. One example is Quercetin Pentaphosphate which we have used as reducing agents and stabilizers. Our approach was achieved at room temperature using water as a solvent and it requires no capping agents. The resulting nanoparticles were spherical, triangular, cubicle, hexagonal and rectangular in shape. They also showed excellent antibacterial activities of 99.9%, 100% and 99.9% growth inhibition for Escherichia coli ATCC® 25922™, Staphylococcus epidermidis ATCC® 12228™ and Citrobacter freundii ATCC® 8090 at 104 cfu inoculations.

As the President and co-founder of the Sustainable Nanotechnology Organization-SNO (, I am also promoting the responsible growth of nanotechnology around the world through research, education and outreach.

Selected Publications:

Francis J. Osonga, Idris Yazgan, Victor Kariuki, David Luther, Apryl Jimenez, Phuong Le & Omowunmi A. Sadik, Greener Synthesis and Characterization, Antimicrobial and Cytotoxicity Studies of Gold Nanoparticles of Novel Shapes and Sizes, RSC Advances, 2016, 6, 2302 – 2313.

Kun Xiang, Yinglei Li, William Ford, Walker Land, David Schaffer, Robert Congdon, Omowunmi Sadik Automated Analysis of Food-borne Pathogens using a Novel Microbial Cell Culture, Sensing and Classification System, Analyst, 2016, 141, 1472 – 1482.

Victor M.  Kariuki , Sohaib A Fasih-Ahmad, Francis J Osonga and Omowunmi A. Sadik, Electrochemical Sensor for Nitrobenzene using π-conjugated Polymer-embedded Nanosilver, Analyst 2016, 14, 2259-2269, DOI: 10.1039/C6an00029k.

Veronica Okello, Francis Osonga, Michael Knipfing, Victor Bushlyar & Omowunmi Sadik, Total Removal of Lead in Water and Sediments using Quercetin and Other Flavonoids, Environmental Science: Processes & Impacts, 2016, 18, 306 – 313, DOI: 10.1039/C5EM00580A.

Francis J. Osonga, Idris Yazgan, Victor Kariuki, David Luther, Apryl Jimenez, Phuong Le & Omowunmi A. Sadik, Greener Synthesis and Characterization, Antimicrobial and Cytotoxicity Studies of Gold Nanoparticles of Different Shapes and Sizes, Journal of Total Environment, 2015 (accepted), doi:10.1016/j.scitotenv.2015.12.064.

Kariuki V., Yazgan I., Akgul A., Kowal A., Parlinska M., Sadik O. Synthesis, Catalytic and Biological Evaluation of Gold and Silver Nanoparticles using Poly(amic) Acid, Environmental Science: Nano, 2015, 2, 518 – 527.

Victor M.  Kariuki · Jing Zhang , Andrzej Kowal , Magdalena Parlinska, Sadik O. A., 3D π-Conjugated Poly (amic) Acid Polymer as Support Matrices for Ethanol Electro-oxidation on Palladium and Platinum Catalysts, Electrocatalysis, 2016 (In Press), DOI 10. 1007/s12678-016-0307-0.

Marco Cinelli, Stuart R. Coles, Omowunmi Sadik, Barbara Karn, Kerry Kirwan, A Framework of Criteria for the Sustainability Assessment of Nanoproducts, Journal of Cleaner Production, (2015) (In Press).

Idris Yazgan, Nian Du, Robert Congdon, Veronica Okello, Omowunmi A. Sadik, Biofunctionalized Poly (amic) Acid Membranes for Disinfection of Drinking Water, Journal of Membrane Science, 2014, 472, 261–271.

Idris Yazgan, Naumih M. Noah, Ousmane Toure, Siyi Zhang and Omowunmi A. Sadik, Biosensor for selective detection of E. coli in spinach using the strong affinity of derivatized mannose with fimbrial lectin, Biosensors & Bioelectronics, 2014, 61, 266-273.

Sadik O. A., Du N., Kariuki V., Okello V., & Bushlyar V., Current and Emerging Technologies for the Characterization of Nanomaterials, ACS Sustainable Chemistry & Engineering, 2014, 2, 1707-1716

Last Updated: 8/10/17