Deoxyribonucleoside-modified squaraines as near-IR viscosity sensors.
Deoxyribonucleoside-modified squaraines were synthesized by Sonogashira coupling reactions using an unsymmetrical, terminal alkynylated benzothiazolium squaraine dye. These non-natural nucleosides exhibited fluorescent 'turn-on' properties in viscous conditions with an enhancement of >300-fold. The viscosity-dependent fluorescence enhancement was attributed to a combination of hampering both molecular aggregation and intramolecular bond rotation of the squaraine probe. Fluorescence microscopy allowed visualization of highly viscous regions during various stages of cellular mitosis.
Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366 (USA).
Yuanwei
Y
Zhang
Xiling
X
Yue
Bosung
B
Kim
Sheng
S
Yao
Kevin D
KD
Belfield
D003503:Cyclobutanes / Q000737:chemistry*; D003853:Deoxyribonucleosides; D005456:Fluorescent Dyes; D008958:Models, Molecular; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry*
D003503:Cyclobutanes; D003853:Deoxyribonucleosides; D005456:Fluorescent Dyes; D010636:Phenols; C480596:squaraine
aggregation; deoxyribonucleosides; near-IR imaging; squaraine dyes; viscosity sensors