Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Dr. Sherine O. Obare

Second Advisor

Dr. Carla Koretsky

Third Advisor

Dr. Yirong Mo

Fourth Advisor

Dr. Ekkehard Sinn


Advances in the chemical, medical and agricultural fields have provided valuable products and resources for a global community. However, some of these advances have had a negative impact on the environment. Chemical and biological pollutants affect our food and water systems and consequently, our quality of life. Pandemic diseases brought about by pathogenic bacteria are of growing concern as we now live in a global community and unexpected exposure is an inevitable possibility. The threat of pandemic diseases is compounded by factors such as the increase in intercontinental travel and commerce, and the expansion of antibiotic resistant among Gram-positive and Gram-negative microorganisms. Thus, new and effective methods to control microbial pathogens are critically needed. The rational design of materials that detect and/or remediate pollutants continues to be in high demand. This dissertation focuses on two classes of pollutants: (1) organophosphorus pesticides and (2) Gram-positive and Gram-negative bacteria. We have developed well-defined metallic and bimetallic nanomaterials based on silver (Ag) and gold (Au) metallic nanoparticles, and Ag/Au bimetallic nanoparticles. The interactions of the unfunctionalized metallic and bimetallic nanoparticles with organophosphorus pesticides were studied in an effort to develop a colorimetric detection system. Furthermore, by functionalizing the surface of metallic nanoparticles with an antibiotic, we have developed an effective method to overcome the antibiotic resistance of microbial pathogens. We show a comparative study for the antimicrobial effects of ampicillin functionalized Ag NPs and Au NPs on clinical isolates of food and water borne pathogens. The design, synthesis, characterization and applications of the materials will be presented.


Though this dissertation is available electronically only on the WMU campus, a print copy can be found in Waldo Library at call number QD 9999.2.S328 and can be requested through Interlibrary Loan.

Access Setting

Dissertation-Campus Only

Restricted to Campus until