Project Summary (2005-2008)

Detection of Superfund chemicals is a first step towards eliminating them from the environment or studying their effect on biological processes. Dr. Daunert's team is developing molecular tools for the highly sensitive and direct detection of Superfund chemicals such as PCBs. These molecular tools include whole cell- and protein-based optical sensing systems. The researchers propose to utilize naturally available operons induced in the presence PCBs and the catabolic enzymes involved in their degradation. They are modifying these operons by incorporating the gene for the reporter, which allows monitoring of their induction in the presence of PCBs. Catabolic enzymes involved in the degradation of PCBs, in particular the enzyme biphenyl dioxygenase (BphAt), is isolated and labeled with signal transduction moieties for the analysis of these compounds. In addition, to improve the selectivity of these catabolic enzymes towards PCB congeners, mutagenesis studies aimed at modifying the active site of the enzyme is being undertaken. In order to make these biosensing systems amenable to field studies and high throughput sample analysis, project investigators are incorporating them into a microfluidics platform. This miniaturized analytical platform has potential for on-site monitoring of Superfund chemicals. Specifically, the researchers are adapting the biosensing systems for PCBs to a compact disc centrifugal microfluidics platform. The advantages of these biosensing systems include sensitivity, portability, and the feasibility of analysis of PCBs in different matrices, such as soil, water, and biological samples.