title: A novel colorimetric biosensor for monitoring and detecting acute toxicity in water.
abstract: This work presents a new colorimetric microorganism biosensor for monitoring and detecting acute toxicity in water, where prussian blue (PB) is used as the colorimetric indicator and E. coli as the model bacterial. In this biosensor, the electron mediator, ferricyanide, accepts electrons from E. coli during respiration to produce ferrocyanide, which subsequently reacts with ferric ions to yield PB, a famous material with a blue color. Since toxicants can inhibit the respiratory activity of E. coli and then reduce the ferrocyanide and consequent PB production, toxicity can be easily detected by measuring the decrease in the production of PB induced by toxicants. Three important toxicants, 3,5-dichlorophenol (DCP), As(3+), Cr(6+) are tested and the detection limits are 3.2, 25, and 3.2 ppm, respectively. Moreover, we could identify the yellow green to dark green color change by naked eye even at concentrations as low as 12.5 ppm for both DCP and Cr(6+). Subsequently, the acute toxicities of groundwater and south lake water are successfully determined by this sensor. This biosensor is rapid, sensitive and cost-effective, and can thus be regarded as a promising biosensor for giving an early warning of acute water toxicity.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhai
authors.forename: Daming
authors.initials: D
authors.lastname: Yong
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D015374:Biosensing Techniques; D002733:Chlorophenols / Q000032:analysis* / Q000737:chemistry; D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D003124:Colorimetry; D004926:Escherichia coli; D005292:Ferricyanides / Q000737:chemistry; D005295:Ferrocyanides / Q000378:metabolism; D060587:Groundwater / Q000737:chemistry; D060106:Lakes / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D014877:Water Pollution, Chemical
chemical_list: D002733:Chlorophenols; D005292:Ferricyanides; D005295:Ferrocyanides; D014874:Water Pollutants, Chemical; D002857:Chromium; C007931:hexacyanoferrate III; C116190:3,5-dichlorophenol; C020354:hexacyanoferrate II; D001151:Arsenic