OSA's Digital Library

Virtual Journal for Biomedical Optics

Virtual Journal for Biomedical Optics


  • Editor: Gregory W. Faris
  • Vol. 5, Iss. 11 — Aug. 25, 2010

Photophysics Associated with Site Selectively Templated and Tagged Xerogel Sensor Platforms

Ellen L. Holthoff and Frank V. Bright

Applied Spectroscopy, Vol. 64, Issue 7, pp. 714-719 (2010)

View Full Text Article

Acrobat PDF (9895 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

  • Export Citation/Save Click for help


The analytical signal produced from a site selectively templated and tagged xerogel (SSTTX) based sensor is more completely elucidated. In an SSTTX, target analyte (TA) binding sites are created within a xerogel and a fluorescent reporter molecule (e.g., nitrobenzo-2-oxa-1,3-diazole, NBD) is covalently and selectively positioned within the template site. TA binding modulates the NBD cybotactic region, yielding a TA concentration-dependent change in the NBD reporter fluorescence. Our results reveal that there are two NBD sub-populations within the SSTTX. One sub-population is associated with misformed template sites that bind TA poorly and the NBD reporter molecules are heavily quenched by an adjacent amine residue that is intentionally positioned within close proximity to the NBD reporter molecule. The second NBD sub-population is associated with a properly formed template site that binds TA; the adjacent amine is still present but it is not as close to the NBD in comparison to the misformed site. When TA is present, the TA-responsive site binds TA, the TA disrupts the adjacent amine–NBD interaction (dequenching), and the NBD fluorescence increases. All NBD quenching occurs via photo-induced electron transfer (PET) from the adjacent amines to the excited NBD reporter molecules. As the mole fraction ratio of n-octyltrimethoxysilane (C8-TMOS) to tetramethoxysilane (TMOS) within an SSTTX increases, the misformed site mole fraction decreases and the dissociation constant (Kd) for TA binding to the TA-responsive site decreases by 13-fold.

Virtual Issues
Vol. 5, Iss. 11 Virtual Journal for Biomedical Optics

Ellen L. Holthoff and Frank V. Bright, "Photophysics Associated with Site Selectively Templated and Tagged Xerogel Sensor Platforms," Appl. Spectrosc. 64, 714-719 (2010)

Sort:  Journal  |  Reset


References are not available for this paper.

Cited By

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited