Detection of Superfund chemicals is a first step towards eliminating them from the environment or studying their effect on biological processes. To that end, we propose to design and develop molecular tools for the highly sensitive and direct detection of Superfund chemicals such as PCBs and their metabolites, hydroxylated PCBs (OH-PCBs). These molecular tools will include whole-cell- and protein-based optical sensing systems. For that, we propose to utilize naturally available bacterial resistance operons induced in the presence of PCBs and OH-PCBs, and the regulatory proteins from such operons involved in their recognition and degradation.
We plan to engineer these operons by incorporating the gene for a reporter, which will allow us to monitor their induction in the presence of PCBs and OH-PCBs. Regulatory proteins involved in the recognition and modulation of the degradation of PCBs and their metabolites, for example the HbpR protein from thehbpoperon, will be redesigned, expressed and purified to develop protein-based molecular switches for these toxic compounds.
In order to make these biosensing systems amenable to field studies and high throughput sample analysis, we propose to incorporate them into a portable, miniaturized analytical platform based on microfluidics principles. Specifically, we plan to adapt our biosensing systems for PCBs and OH-PCBS to a compact disc centrifugal microfluidics platform. As part of the implementation of enabling technologies to enhance the on-site monitoring of Superfund chemicals, we will develop a strategy involving the transformation of our whole-cell sensing systems into naturally hardy spores to achieve long-term, highly-rugged elements for storage and transport of biosensors. These spore-based biosensing systems could also be incorporated into a variety of portable sensing platforms.
The advantages of our proposed biosensing systems include sensitivity, selectivity, rapidity, portability, and the feasibility of analysis of PCBs and OH-PCBs in different matrices, such as soil, water, and biological samples.
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