Team:Bielefeld-CeBiTec/Overview
Abstract
We developed versatile cell-free biosensors that can be used as paper-based test strips. These offer significant advantages over conventional biosensors regarding biosafety, ease of use and shelf life. We created two technical approaches built upon self-made E. coli cell extract for cell-free protein synthesis (CFPS) and our newly established, fluorescence based Plasmid Repressor Interaction Assay (PRIA). Both can be immobilized on paper and lyophilized for long term storage. We developed an app that enables the detection of a fluorescence signal with your smartphone in combination with our specially designed black case. With these novel biosensor designs we show the universal applicability of our concept. To show this we tackle the problem of date rape drug intoxication, which is of increasing relevance in our area, by detecting a common ingredient. The second major problem we wanted to address is the contamination of water with heavy metals. Heavy metal sensors designed by previous iGEM teams as well as novel biosensors are combined to a modular, cell-free test strip for simultaneous detection. All in all, we are providing an extensible biosensor system on paper as a valuable tool for water quality analysis for everyone.
Our biosensors are based on cell-free protein synthesis. The cell extract, made from disrupted E. coli cells, can be applied onto paper. In the presence of an analyte, a reporter protein such as GFP is expressed.
The Plasmid Repressor Interaction Assay is an alternative biosensor design. It works on the principle of a repressor binding to DNA. Interaction with the analyte induces a conformational change, which results in release of the DNA and a loss of the fluorescence signal.
We designed biosensors to detect heavy metals, which are still a massive problem all over the world, as well as date rape drugs, which are currently a major problem in our area. These biosensors are based on a common concept, detection is carried out by fluorescence.
Fluorescence analysis outside the lab sounds complicated, but it is not. Two filters and a smartphone enable everyone to specifically detect fluorescence, and our app analyzes the results.
