title: Programmable living material containing reporter micro-organisms permits quantitative detection of oligosaccharides.
abstract: The increasing molecular understanding of many diseases today permits the development of new diagnostic methods. However, few easy-to-handle and inexpensive tools exist for common diseases such as food disorders. Here we present a living material based analytical sensor (LiMBAS) containing genetically modified bacteria (Escherichia coli) immobilized and protected in a thin layer between a nanoporous and support polymer membrane for a facile quantification of disease-relevant oligosaccharides. The bacteria were engineered to fluoresce in response to the analyte to reveal its diffusion behavior when using a blue-light source and optical filter. We demonstrated that the diffusion zone diameter was related semi-logarithmically to the analyte concentration. LiMBAS could accurately quantify lactose or galactose in undiluted food samples and was able to measure food intolerance relevant concentrations in the range of 1-1000 mM requiring a sample volume of 1-10 μL. LiMBAS was storable for at least seven days without losing functionality at 4 °C. A wide range of genetic tools for E. coli are readily available thus allowing the reprogramming of the material to serve as biosensor for other molecules. In combination with smartphones, an automated diagnostic analysis becomes feasible which would also allow untrained people to use LiMBAS.
authors.affiliation: Institute for Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Mora
authors.affiliation: Institute for Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland.
authors.forename: Antoine F
authors.initials: AF
authors.lastname: Herzog
authors.affiliation: Institute for Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland.
authors.forename: Renzo A
authors.initials: RA
authors.lastname: Raso
authors.affiliation: Institute for Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland. Electronic address: wendelin.stark@chem.ethz.ch.
authors.forename: Wendelin J
authors.initials: WJ
authors.lastname: Stark
mesh_terms: D001681:Biological Assay / Q000295:instrumentation*; D015374:Biosensing Techniques / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology*; D017930:Genes, Reporter; D005818:Genetic Engineering / Q000379:methods; D008163:Luminescent Measurements / Q000295:instrumentation*; D009844:Oligosaccharides / Q000032:analysis* / Q000494:pharmacology*
chemical_list: D009844:Oligosaccharides
keywords: Bacteria; Fluorescence; Food allergies; Galactosaemia; Genetic engineering; Membrane; Whole-cell biosensor