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Several New Clarkson University Professors Join CAMP

CAMP introduces its newest faculty members.
They include Professors Silvana Andreescu, Feng Hua, Narayanan Neithalath, and Suresh Dhaniyala.

Professor Silvana Andreescu

Dr.Silvana Andreescu joined the Department of Chemistry and Biomolecular Science at Clarkson University in July 2005. She received her Ph.D. in 2002 in Analytical Chemistry from the University of Bucharest, Romania and in Agrochemistry from the University of Perpignan, France as a result of an international collaboration. Before joining Clarkson, she was a NATO-NSF postdoctoral fellow at the State University of New York at Binghamton. Andreescu’s research interests include both basic and applied research in Analytical and Bio-analytical Chemistry, (Bio)electrochemistry and the Environment. Her research focuses on the development of novel (bio)compatible materials and nanomaterials for more effective, reliable biosensing systems. This will have applications to environmental monitoring, public safety, food and clinical control. Other interests include modification of surfaces with (bio) molecule receptors, nano(bio)materials, microencapsulation techniques and bioremediation.

Professor Andreescu is currently investigating the use of natural biopolymers for the removal of phenols and pesticides from wastewaters. The purpose is for the development of polymeric microcapsules with entrapped biological materials (cells or enzymes). The microcapsules are fabricated in a core-shell structure. A biomolecule is encapsulated inside the core and is selected to ensure a biocatalytic conversion of the contaminant of interest into a product, which can then be adsorbed or reacted with the core material. This can be easily noticed by the change in color from white to brown or black (Figure 4). The shell prevents the leaching of the bioreagent and/or reaction product into the solution and avoids direct exposure to the environment. These capsules are fully functional and extremely stable at room temperature (for several weeks), which is remarkable considering the fragility of biological material, which generally requires special storage and handling conditions. During the study, the group is investigating the conditions for ensuring high stability and activity of the biological material and to avoid leaching. These core-shell structures with encapsulated biological materials could also find application in catalytic processes in biotechnology, for the construction of bioreactors and in drug delivery.

Natural biopolymers containing a high density of functional –COOH and NH 2 groups are also explored by Andreescu’s group for immobilizing biological material (cells and enzymes) onto electrode surfaces. The ultimate goal is to develop biosensors in which biological material remains fully active over a long period of time (several months) and that are able to detect very low amounts of pesticides in aqueous and organic media.

A                                                               B

Figure 4. Polymeric core-shell microcapsules containing biocatalytic material in the absence (A) and presence (B) of a phenolic contaminant.

Another research direction pursued by Andreescu’s group involves the study and characterization of nanostructured materials for use in biotechnology and biosensors. The group has recently developed a method for preparing stable microfibers of Au nanoparticles-conducting polymer composite (Figure 5) in which enzymes remain fully active during manufacturing, storage and use. The synthesis occurs in mild aqueous conditions and does not involve surfactants or solvents that could affect the biological activity of the enzyme. The enzyme is entrapped within the fibers and shows remarkable long-term stability. The fibers are stable, robust, easy to handle and could be obtained either in a dry state or suspended in aqueous solution. Due to the high conductivity of the polymer that is further enhanced by the presence of gold nanoparticles, these microstructures could be used as transducer materials in electrochemical biosensors. Following this approach, Andreescu’s group has recently developed enzyme biosensors for sensitive detection of various analytes of interest in environmental (phenols, pesticides) and clinical (glucose) control. In addition, an interesting application of these polymer supported metallic particles is their use in catalysis. The polymer stabilizes the particles and serves as a matrix for the incorporation and the self-assembly of metal nanoparticles on anode materials. Their high conductivity and electronic properties could facilitate better transport of fuel and much higher catalyst utilization. The group is now exploring the potential of these structures as anode material in direct methanol fuel cells.

A                               B

Figure 5. SEM analysis of Au-polymer composite at x 4000 magnification (A). TEM image of metallic gold entrapped within the polymer microfibers (B).

For more information about Professor Silvana Andreescu and her research,
you may call her at 315-268-2394 or send email to eandrees@clarkson.edu
.

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