title: Visible fluorescence chemosensor for saxitoxin.
abstract: Absorption spectra of a number of shellfish extracts have been obtained and reveal prominent absorptions in all samples at 210 and 260 nm and at 325 nm in some of them. These absorptions preclude the use of chromophores with similar absorptions in testing of shellfish samples for paralytic shellfish toxins. Two crown ether chemosensors featuring a boron azadipyrrin chromophore have been synthesized; both have absorption maxima at 650 nm, where all the shellfish extracts are transparent. The synthetic sensors feature either 18- or 27-membered crown ether rings and have been evaluated as visible sensors for the paralytic shellfish toxin saxitoxin. The binding constant for one of them is in the range of 3-9x10(5) M-1 and exhibits a fluorescence enhancement of over 100% at 680 nm in the presence of 40 microM saxitoxin.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA. bgawley@uark.edu
authors.forename: Robert E
authors.initials: RE
authors.lastname: Gawley
authors.forename: Hua
authors.initials: H
authors.lastname: Mao
authors.forename: M Mahbubul
authors.initials: MM
authors.lastname: Haque
authors.forename: John B
authors.initials: JB
authors.lastname: Thorne
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Pharr
mesh_terms: D000818:Animals; D043844:Crown Ethers; D005453:Fluorescence; D008387:Marine Toxins / Q000032:analysis; D012530:Saxitoxin / Q000032:analysis*; D012758:Shellfish / Q000633:toxicity
chemical_list: D043844:Crown Ethers; D008387:Marine Toxins; D012530:Saxitoxin