Understanding the surface chemistry of different colloidal systems – applications towards chemical and biological sensing, and waste disposal

Gopala-Krishna Darbha

Geoscience Center Göttingen, Dept. of Sedimentology/Environmental Geology

Talk by Gopala-Krishna Darbha in MN 16, on Tuesday, 9th December 2008, 16:15h

The topic is aimed at understanding the interaction of gold nanostructures with bio and chemo systems and thus, exploring the application of gold nanoparticles (spheres and rods) in DNA diagnostics and sensing chemical toxins such as mercury. Contamination of the environment with pathogens and heavy metal ions has been an important concern throughout the world for decades. Rapid differentiation and accurate identification of these biological and chemical hazards are crucial to timely planning and appropriate measures for public safety. Compared to other nanoparticles, gold nanoparticles are proven to be useful in biological systems because of their non-toxicity and extraordinary physical and chemical properties. A miniaturized, battery operated, portable sensor has been designed to sense the bioagents (such as E-coli and anthrax) for on-site analysis. The same sensor has been utilized to analyze the Hg2+ concentration in various environmental samples at EPA permissible limit 2ppb. Continuation to the research, current interests are toward understanding the interaction between different metals colloids and rock surfaces for sedimentation.