Dual-fluorophore ratiometric pH nanosensor with tuneable pKa and extended dynamic range

Abstract

Ratiometric pH nanosensors with tuneable pKa were prepared by entrapping combinations of two pH-sensitive fluorophores (fluorescein isothiocyanate dextran (FITC-D) and Oregon Green® dextran (OG-D)) and a reference fluorophore (5-(and-6)-carboxytetramethylrhodamine dextran (TAMRA-D)), in a biocompatible polymer matrix. Dual-fluorophore pH nanosensors permit the measurement of an extended dynamic range, from pH 4.0 to 7.5. © 2011 The Royal Society of Chemistry.