000167527 001__ 167527
000167527 005__ 20190316235152.0
000167527 0247_ $$2doi$$a10.1039/c1lc20274j
000167527 022__ $$a1473-0189
000167527 02470 $$2ISI$$a000292168500010
000167527 037__ $$aARTICLE
000167527 245__ $$aDevelopment of a microfluidics biosensor for agarose-bead immobilized Escherichia coli bioreporter cells for arsenite detection in aqueous samples
000167527 269__ $$a2011
000167527 260__ $$c2011
000167527 336__ $$aJournal Articles
000167527 520__ $$aContamination with arsenic is a recurring problem in both industrialized and developing countries. Drinking water supplies for large populations can have concentrations much higher than the permissible levels (for most European countries and the United States, 10 mu g As per L; elsewhere, 50 mu g As per L). Arsenic analysis requires high-end instruments, which are largely unavailable in developing countries. Bioassays based on genetically engineered bacteria have been proposed as suitable alternatives but such tests would profit from better standardization and direct incorporation into sensing devices. The goal of this work was to develop and test microfluidic devices in which bacterial bioreporters could be embedded, exposed and reporter signals detected, as a further step towards a complete miniaturized bacterial biosensor. The signal element in the biosensor is a nonpathogenic laboratory strain of Escherichia coli, which produces a variant of the green fluorescent protein after contact to arsenite and arsenate. E. coli bioreporter cells were encapsulated in agarose beads and incorporated into a microfluidic device where they were captured in 500 x 500 mu m(2) cages and exposed to aqueous samples containing arsenic. Cell-beads frozen at -20 degrees C in the microfluidic chip retained inducibility for up to a month and arsenic samples with 10 or 50 mu g L-1 could be reproducibly discriminated from the blank. In the 0-50 mu g L-1 range and with an exposure time of 200 minutes, the rate of signal increase was linearly proportional to the arsenic concentration. The time needed to reliably and reproducibly detect a concentration of 50 mu g L-1 was 75-120 minutes, and 120-180 minutes for a concentration of 10 mu g L-1
000167527 6531_ $$aGenetically-Engineered Bacteria
000167527 6531_ $$aGroundwater
000167527 6531_ $$aWater
000167527 6531_ $$aAntimonite
000167527 6531_ $$aToxicity
000167527 6531_ $$aBioassay
000167527 6531_ $$aHealth
000167527 6531_ $$aKits
000167527 700__ $$0242548$$g166591$$aBuffi, Nina
000167527 700__ $$aMerulla, Davide
000167527 700__ $$aBeutier, Julien
000167527 700__ $$aBarbaud, Fanny
000167527 700__ $$aBeggah, Siham
000167527 700__ $$0240656$$g117098$$aVan Lintel, Harald
000167527 700__ $$aRenaud, Philippe$$g107144$$0240219
000167527 700__ $$aRoelof Van Der Meer, Jan
000167527 773__ $$j11$$tLab on a Chip$$k14$$q2369-2377
000167527 8564_ $$uhttps://infoscience.epfl.ch/record/167527/files/Buffi%272011-LabChip.pdf$$zn/a$$s564947$$yPublisher's version
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000167527 917Z8 $$x113143
000167527 937__ $$aEPFL-ARTICLE-167527
000167527 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000167527 980__ $$aARTICLE