Interdisciplinary PhD in Molecular Biosciences

Dr. Charles Chusuei - Research

The Chusuei Laboratory has two primary research interests pertaining to which are intertwined by a theme of using a surface science approach to characterize atomic-scale surface structures of solids that interact with their surroundings:

I. FABRICATION OF CARBON NANOMATERIALS FOR BIOLOGICAL SENSING:

Our laboratory explores strategies to functionalize carbon nanomaterials to alter its surface properties for applications in biological sensing. The relevance of this work has recently been underscored by the 2010 Nobel Prize in Physics. The principle question we wish to explore is: Within the carbon nanomaterial graphene surface structure, what is the role of chemical activity played by surface adsorbed or functionalized non-reactants? By non-reactants, I mean those additives that influence the electronic or structural nature of the surface-active species. They may be adsorbed metallic or metal oxide nanoparticles, functional groups or electron withdrawing or donating moieties that influence the active site directly or through the support. Changes in structure may affect surface properties important for electrocatalytic behavior and fluorescence of tethered metal oxide particles, both of which are important for biological sensors. Success in understanding the modification of local electronic structures accompanying these non-reactants will help rationalize material design to detect trace amounts of biological markers, e.g., release of H 2O 2 in solution for cancer screening.

II. ELUCIDATING THE FATE AND IMPACT OF NANOMATERIALS:

With the rise in global population and increasing pressure on the Earth's limited resources, the world is facing formidable challenges in environmental health and protection. Sensing, detection and remediation of environmental pollutants are therefore urgent challenges that need to be addressed with existing and emerging technologies. Equally as important as designing improved devices for these applications is keeping abreast of fundamental phenomena governing toxicity of nanomaterials and their adsorption and release into aqueous solution environments (i.e., groundwater) that may well impact biological systems (applications in nanomedicine) or ecosystems. To this end, our studies entail characterization of specific binding interactions of toxic (or potentially toxic) materials with the solid surface to aid in remediation and containment strategies.

Our laboratory offers expertise in and applies the following surface analytical tools:

  • X-ray photoelectron (XPS) and Auger electron (AES) spectroscopies
  • Atomic force microscopy (AFM)
  • Attenuated Total Reflection Infrared Spectroscopy (ATR-IR)
  • Extended X-ray Absorption Fine Structure (EXAFS) (available at the National Synchrotron Light Source at Brookhaven National Laboratory)
  • Transmission electron microscopy (TEM) (equipped with energy dispersive spectroscopy)