Miniaturized bacterial biosensor system for arsenic detection holds great promise for making integrated measurement device.
Combining bacterial bioreporters with microfluidics systems holds great promise for in-field detection of chemical or toxicity targets. Recently we showed how Escherichia coli cells engineered to produce a variant of green fluorescent protein after contact to arsenite and arsenate can be encapsulated in agarose beads and incorporated into a microfluidic chip to create a device for in-field detection of arsenic, a contaminant of well known toxicity and carcinogenicity in potable water both in industrialized and developing countries. Cell-beads stored in the microfluidics chip at -20°C retained inducibility up to one month and we were able to reproducibly discriminate concentrations of 10 and 50 μg arsenite per L (the drinking water standards for European countries and the United States, and for the developing countries, respectively) from the blank in less than 200 minutes. We discuss here the reasons for decreasing bioreporter signal development upon increased storage of cell beads but also show how this decrease can be reduced, leading to a faster detection and a longer lifetime of the device.
Laboratory of Microsystems Engineering LMIS4, Ecole Polytechnique Fédérale Lausanne, EPFL-STI-LMIS, Station 17, CH-1015 Lausanne, Switzerland. Nina.buffi@epfl.ch
Nina
N
Buffi
Davide
D
Merulla
Julien
J
Beutier
Fanny
F
Barbaud
Siham
S
Beggah
Harald
H
van Lintel
Philippe
P
Renaud
Jan Roelof
JR
van der Meer
D001151:Arsenic / Q000032:analysis* / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism; D014881:Water Supply
D014874:Water Pollutants, Chemical; D001151:Arsenic