Aggregation control of squaraines and their use as near-infrared fluorescent sensors for protein.
A series of squaraine dyes are found to be in H- or J-aggregates and are almost nonfluorescent in aqueous solution. Upon addition of bovine serum albumin (BSA), however, the fluorescence intensity (at lambda(em) approximately 690 nm) increases by a factor of up to 200. Transformation of the dye molecules from the aggregates to the monomeric species appears to be responsible for the large fluorescence turn-on. While both H- and J-aggregates contribute to the observed fluorescence turn-on, the former appears to play a more important role. Electrophoresis imaging shows that these probes are good BSA indicators.
Xu
Yongqian
Y
Department of Chemistry & Maurice Morton Institute of Polymer Science, The University of Akron, Akron, Ohio 44325, USA.
Li
Zhiyong
Z
Malkovskiy
Andrey
A
Sun
Shiguo
S
Pang
Yi
Y
D000818:Animals; D002417:Cattle; D003503:Cyclobutanes / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D008968:Molecular Conformation; D010636:Phenols / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D003503:Cyclobutanes; D010636:Phenols; C480596:squaraine; D012710:Serum Albumin, Bovine