1 Center of Excellence for Polysaccharide Research, Member of the European Polysaccharide Network of Excellence, Friedrich Schiller University of Jena, Humboldtstrasse 10, 07743 Jena, Germany. thomas.heinze@uni-jena.de.
2 Institute of Physiology II, Universitätsklinikum Jena, Teichgraben 8, 07740 Jena, Germany.
3 Institute of Physical Chemistry, Friedrich Schiller University of Jena, Lessingstrasse 10, 07743 Jena, Germany. gerhard.mohr@uni-jena.de.
Dialysis of a mixture of fluorescein and sulforhodamine B marked dextran derivatives yields biocompatible and tuneable nanosensors that can be used for ratiometric pH measurements.