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Photonic crystal sensor for organophosphate nerve agents utilizing the organophosphorus hydrolase enzyme

Walker, JP and Kimble, KW and Asher, SA (2007) Photonic crystal sensor for organophosphate nerve agents utilizing the organophosphorus hydrolase enzyme. Analytical and Bioanalytical Chemistry, 389 (7-8). 2115 - 2124. ISSN 1618-2642

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We developed an intelligent polymerized crystalline colloidal array (IPCCA) photonic crystal sensing material which reversibly senses the organophosphate compound methyl paraoxon at micromolar concentrations in aqueous solutions. A periodic array of colloidal particles is embedded in a poly-2- hydroxyethylacrylate hydrogel. The particle lattice spacing is such that the array Bragg-diffracts visible light. We utilize a bimodular sensing approach in which the enzyme organophosphorus hydrolase (OPH) catalyzes the hydrolysis of methyl paraoxon at basic pH, producing p-nitrophenolate, dimethylphosphate, and two protons. The protons lower the pH and create a steady-state pH gradient. Protonation of the phenolates attached to the hydrogel makes the free energy of mixing of the hydrogel less favorable, which causes the hydrogel to shrink. The IPCCA's lattice constant decreases, which blueshifts the diffracted light. The magnitude of the steady-state diffraction blueshift is proportional to the concentration of methyl paraoxon. The current detection limit is 0.2 μmol methyl paraoxon per liter. © 2007 Springer-Verlag.


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Item Type: Article
Status: Published
CreatorsEmailPitt UsernameORCID
Walker, JP
Kimble, KW
Asher, SAasher@pitt.eduASHER
Date: 1 December 2007
Date Type: Publication
Journal or Publication Title: Analytical and Bioanalytical Chemistry
Volume: 389
Number: 7-8
Page Range: 2115 - 2124
DOI or Unique Handle: 10.1007/s00216-007-1599-y
Schools and Programs: Dietrich School of Arts and Sciences > Chemistry
Refereed: Yes
ISSN: 1618-2642
MeSH Headings: Aryldialkylphosphatase--chemistry; Aryldialkylphosphatase--metabolism; Biosensing Techniques--methods; Chemical Warfare Agents--analysis; Colloids--chemistry; Crystallization; Hydrogels--chemistry; Hydrogen-Ion Concentration; Microarray Analysis; Microchemistry; Nitrophenols--chemistry; Organophosphates--analysis; Paraoxon--analogs & derivatives; Paraoxon--analysis; Photons; Water--chemistry
PubMed ID: 17899031
Date Deposited: 08 Feb 2013 21:06
Last Modified: 02 Feb 2019 16:55


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