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Progress toward the development of a point-of-care photonic crystal ammonia sensor

Kimble, KW and Walker, JP and Finegold, DN and Asher, SA (2006) Progress toward the development of a point-of-care photonic crystal ammonia sensor. Analytical and Bioanalytical Chemistry, 385 (4). 678 - 685. ISSN 1618-2642

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We have developed an ammonia-sensitive material by coupling the Berthelot reaction to our polymerized crystalline colloidal array (PCCA) technology. The material consists of a periodic array of highly charged colloidal particles (110 nm diameter) embedded in a poly(hydroxyethyl acrylate) hydrogel. The particles have a lattice spacing such that they Bragg-diffract visible light. In the Berthelot reaction, ammonia, hypochlorite, and phenol react to produce the dye molecule indophenol blue in an aqueous solution. We use this reaction in our sensor by covalently attaching 3-aminophenol to the hydrogel backbone, which forms cross-links through the Berthelot mechanism. Ammonia reacts with hypochlorite, forming monochloramine, which then reacts with a pendant aminophenol to form a benzoquinone chlorimine. The benzoquinone chlorimine reacts with another pendant aminophenol to form a cross-link. The creation of new cross-links causes the hydrogel to shrink, which reduces the lattice spacing of the embedded colloidal array. This volume change results in a blue-shift in the diffracted light proportional to the concentration of NH3 in the sample. We demonstrate that the NH3 photonic crystal sensing material is capable of quantitative determination of concentrations in the physiological range (50-350 μmol NH3 L-1) in human blood serum.


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Item Type: Article
Status: Published
CreatorsEmailPitt UsernameORCID
Kimble, KW
Walker, JP
Finegold, DN
Asher, SAasher@pitt.eduASHER
Date: 1 June 2006
Date Type: Publication
Journal or Publication Title: Analytical and Bioanalytical Chemistry
Volume: 385
Number: 4
Page Range: 678 - 685
DOI or Unique Handle: 10.1007/s00216-006-0453-y
Schools and Programs: Dietrich School of Arts and Sciences > Chemistry
Refereed: Yes
ISSN: 1618-2642
MeSH Headings: Ammonia--chemistry; Calibration; Colloids; Crystallization; Microarray Analysis; Molecular Structure; Photochemistry
PubMed ID: 16741766
Date Deposited: 08 Feb 2013 21:11
Last Modified: 22 Jun 2021 11:55


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