title: Standoff detection of explosives and buried landmines using fluorescent bacterial sensor cells.
abstract: A standoff detection scheme for buried landmines and concealed explosive charges is presented. The detection procedure consists of the following: Live bacterial sensor strains, genetically engineered to produce a dose-dependent amount of green fluorescent protein (GFP) in the presence of explosives' vapors, are encapsulated and spread on the suspected area. The fluorescence produced by the bacteria in response to traces of the explosive material in their microenvironment is remotely detected by a phase-locked optoelectronic sampling system. This scheme enables fast direct access to a large minefield area, while obviating the need to endanger personnel and equipment. Moreover, the employment of phase locking detection efficiently isolates the bacterial sensors' fluorescent output from the background optical signals. This facilitates the application of bacterial sensors in an outdoor environment, where control of background illumination is not possible. Using this system, we demonstrate standoff detection of 2,4-DNT both in aqueous solution and when buried in soil, by sensor bacteria either in liquid culture or agar-immobilized, respectively, at a distance of 50 m in a realistic optically noisy environment.
authors.affiliation: Department of Applied Physics and the Brojde Center for Innovative Engineering and Computer Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. Electronic address: yossi.kabessa@mail.huji.ac.il.
authors.forename: Yossef
authors.initials: Y
authors.lastname: Kabessa
authors.affiliation: Department of Applied Physics and the Brojde Center for Innovative Engineering and Computer Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Ori
authors.initials: O
authors.lastname: Eyal
authors.affiliation: Department of Applied Physics and the Brojde Center for Innovative Engineering and Computer Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Ofer
authors.initials: O
authors.lastname: Bar-On
authors.affiliation: Department of Applied Physics and the Brojde Center for Innovative Engineering and Computer Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Victor
authors.initials: V
authors.lastname: Korouma
authors.affiliation: Department of Plant & Environmental Sciences, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Sharon
authors.initials: S
authors.lastname: Yagur-Kroll
authors.affiliation: Department of Plant & Environmental Sciences, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Shimshon
authors.initials: S
authors.lastname: Belkin
authors.affiliation: Department of Applied Physics and the Brojde Center for Innovative Engineering and Computer Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Aharon J
authors.initials: AJ
authors.lastname: Agranat
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004136:Dinitrobenzenes / Q000032:analysis*; D004867:Equipment Design; D004926:Escherichia coli / Q000235:genetics; D053834:Explosive Agents / Q000032:analysis*; D005453:Fluorescence; D017930:Genes, Reporter; D005818:Genetic Engineering; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D012989:Soil Pollutants / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004136:Dinitrobenzenes; D053834:Explosive Agents; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D049452:Green Fluorescent Proteins; C016403:2,4-dinitrotoluene
keywords: Bacterial whole-cell biosensors; Explosives; Fluorescence; GFP reporter gene; Remote sensing; Standoff detection