Luminescent nanobeads for optical sensing and imaging of pH

CHED 271

Sergey M. Borisov, sergey.borisov@tugraz.at1, Danielle L. Slomberg, d-slomberg@onu.edu2, and Ingo Klimant, ingo.klimant@tugraz.at1. (1) Institute of Analytical Chemistry and Radiochemistry, University of Technology Graz, Stremayrgasse 16, 8010 Graz, Austria, (2) Department of Chemistry and Biochemistry, Ohio Northern University, 525 S. Main St., Ada, OH 45810
Luminescent nanosensors represent highly versatile analytical tools which enable non-invasive and contactless determination of oxygen, pH, temperature, and ions in a variety of biological and physiological media. Moreover, the nanosensors allow for 3-D imaging using confocal methods. Optical nanosensors for pH are of much interest in biology and marine science. Here we present a variety of fluorescent pH nanosensors based on poly(styrene-block-vinylpyrrolidone) nanobeads (diameter < 500 nm). The lipophilic derivatives of fluorescein and 8-hydroxy-pyrene-1,3,6-trisulfonate are incorporated into the nanobeads and do not leach out, even in complex media. Important features include the possibility of self-referenced ratiometric measurements for fluorescein-based nanosensors, virtually instantaneous response times, and high flexibility in tuning the dynamic range of the sensors. The nanosensors are suitable for measurements in slightly acidic and basic media in addition to physiological media. We also present a cascade system which enables reliable monitoring of pH in a broad range (pH 3-10).
 

Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008