Fabrication and characterization of a nitric oxide-releasing optical fiber pH sensor

ANYL 114

Gregory W. Charville, gc@unc.edu, Kevin P. Dobmeier, dobmeier@email.unc.edu, and Mark H. Schoenfisch, schoenfi@email.unc.edu. Department of Chemistry, University of North Carolina at Chapel Hill, CB #3290, Chapel Hill, NC 27599
Nitric oxide (NO)-releasing polymers have been shown to reduce platelet adhesion and enhance the performance of intravascular chemical sensors. Herein, we report the fabrication of a NO-releasing, xerogel-derived optical fiber pH sensor. The tapered end of an optical fiber was coated with a biphasic membrane consisting of an indicator-doped tetramethylorthosilicate (TMOS) layer applied on top of a N-(6-aminohexyl) aminopropyltrimethoxysilane (AHAP3)-modified ethyltrimethoxysilane (ETMOS) layer capable of releasing NO. Seminaphthorhodamine-1 carboxylate, a self-referencing pH indicator, was employed to limit signal drift due to photobleaching. The sensor exhibited a response time of 7.8 ± 1.3 sec (t90% for a pH shift from 7.0 to 7.8), a signal drift of 2.1% over a 7 h period, and a minimum resolvable pH shift of 0.02 units. Sensor response was linear (R2=0.983) over a physiologically relevant range. Following exposure to platelet-rich media, the NO-releasing membrane retained significantly fewer platelets relative to the control.
 

General Papers
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Analytical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006