1. A paper-based, cell-free biosensor system for the detection of heavy metals and date rape drugs
- Author
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Gräwe, Alexander, Dreyer, Anna, Vornholt, Tobias, Barteczko, Ursela, Buchholz, Luzia, Drews, Gila, Ho, Uyen Linh, Jackowski, Marta Eva, Kracht, Melissa, Lüders, Janina, Bleckwehl, Tore, Rositzka, Lukas, Ruwe, Matthias, Wittchen, Manuel, Lutter, Petra, Müller, Kristian, and Kalinowski, Jörn
- Subjects
Agrobacteria ,Light ,Hydroxybutyrates ,Gene Expression ,Biosensing Techniques ,Protein Synthesis ,Plant Science ,Biochemistry ,Plant Microbiology ,Physics ,Electromagnetic Radiation ,Chemical Synthesis ,Detectors ,Substance Abuse Detection ,Chemistry ,Artificial Light ,Physical Sciences ,Engineering and Technology ,Medicine ,Synthetic Biology ,Research Article ,Chemical Elements ,Biosynthetic Techniques ,Science ,Green Fluorescent Proteins ,Equipment ,Research and Analysis Methods ,Agrobacterium Tumefaciens ,Microbiology ,Metals, Heavy ,DNA-binding proteins ,Genetics ,Humans ,Gene Regulation ,Communication Equipment ,Cell-Free System ,Bacteria ,Illicit Drugs ,Organisms ,Biology and Life Sciences ,Proteins ,Regulatory Proteins ,Biosensors ,Rape ,Metallic Mercury ,Cell Phones ,Water Pollutants, Chemical ,Synthetic Biosensors ,Transcription Factors - Abstract
Biosensors have emerged as a valuable tool with high specificity and sensitivity for fast and reliable detection of hazardous substances in drinking water. Numerous substances have been addressed using synthetic biology approaches. However, many proposed biosensors are based on living, genetically modified organisms and are therefore limited in shelf life, usability and biosafety. We addressed these issues by the construction of an extensible, cell-free biosensor. Storage is possible through freeze drying on paper. Following the addition of an aqueous sample, a highly efficient cell-free protein synthesis (CFPS) reaction is initiated. Specific allosteric transcription factors modulate the expression of 'superfolder' green fluorescent protein (sfGFP) depending on the presence of the substance of interest. The resulting fluorescence intensities are analyzed with a conventional smartphone accompanied by simple and cheap light filters. An ordinary differential equitation (ODE) model of the biosensors was developed, which enabled prediction and optimization of performance. With an optimized cell-free biosensor based on the Shigella flexneri MerR transcriptional activator, detection of 6 mug/L Hg(II) ions in water was achieved. Furthermore, a completely new biosensor for the detection of gamma-hydroxybutyrate (GHB), a substance used as date-rape drug, was established by employing the naturally occurring transcriptional repressor BlcR from Agrobacterium tumefaciens.
- Published
- 2019