@article {1217, title = {Chemically diverse small molecule fluorescent chemosensors for copper ion}, journal = {Coordination Chemistry Reviews}, volume = {357}, year = {2018}, pages = {50 - 104}, keywords = {Chemosensors, Fluorescence, Live cell imaging, Small molecules, Turn-off, Turn-on}, issn = {0010-8545}, doi = {https://doi.org/10.1016/j.ccr.2017.11.020}, url = {http://www.sciencedirect.com/science/article/pii/S0010854517306537}, author = {Gandhi Sivaraman and Murugan Iniya and Thangaraj Anand and Niranjan G. Kotla and Omprakash Sunnapu and Subramanian Singaravadivel and Akash Gulyani and Duraisamy Chellappa} } @article {1191, title = {Tunable Emission from Fluorescent Organic Nanoparticles in Water: Insight into the Nature of Self-Assembly and Photoswitching}, journal = {Chemistry {\textendash} A European Journal}, volume = {24}, year = {2018}, pages = {2643-2652}, abstract = {

Abstract Excitation-dependent tuning of the emission behavior of fluorescent organic nanoparticles (FONs) with two simple luminescent pyrenyl{\textendash}pyridyl conjugates as model systems is demonstrated. In the case of the compound with a flexible bis-picolyl moiety, the simultaneous presence of multiple ground-state species with distinct absorption and emission characteristics can be observed. The relative ratios of these species can easily be modulated, and it is possible to selectively stimulate any one of them individually by choosing an appropriate excitation channel. Moreover, at high concentration, a drastic change in the nature of the self-assembly is observed, which shifts from donor{\textendash}acceptor-type self-assembly to exciplex-type self-agglomeration. On the contrary, the compound containing a rigid terpyridine unit has only a single ground state and shows no such tunable emission. However, it can exhibit multiple emission bands in water, whereby the positions of their emission maxima depend on the extent of aggregation-induced planarization of the probe molecules. Overall, this work demonstrates multimodal modulation of FON emission and a gives insight into how molecular order can translate into complete switching of nanoparticle self-assembly and photophysics.

}, keywords = {aggregation, Fluorescence, nanoparticles, self-assembly}, doi = {10.1002/chem.201704607}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/chem.201704607}, author = {Gulyani Akash and Dey Nilanjan and Bhattacharya Santanu} } @article {1167, title = {Blue protein with red fluorescence.}, journal = {Proc Natl Acad Sci U S A}, volume = {113}, year = {2016}, month = {2016 10 11}, pages = {11513-11518}, abstract = {

The walleye (Sander vitreus) is a golden yellow fish that inhabits the Northern American lakes. The recent sightings of the blue walleye and the correlation of its sighting to possible increased UV radiation have been proposed earlier. The underlying molecular basis of its adaptation to increased UV radiation is the presence of a protein (Sandercyanin)-ligand complex in the mucus of walleyes. Degradation of heme by UV radiation results in the formation of Biliverdin IXα (BLA), the chromophore bound to Sandercyanin. We show that Sandercyanin is a monomeric protein that forms stable homotetramers on addition of BLA to the protein. A structure of the Sandercyanin-BLA complex, purified from the fish mucus, reveals a glycosylated protein with a lipocalin fold. This protein-ligand complex absorbs light in the UV region (λ of 375 nm) and upon excitation at this wavelength emits in the red region (λ of 675 nm). Unlike all other known biliverdin-bound fluorescent proteins, the chromophore is noncovalently bound to the protein. We provide here a molecular rationale for the observed spectral properties of Sandercyanin.

}, keywords = {Biliverdine, Crystallography, X-Ray, Fluorescence, Models, Molecular, Proteins, Recombinant Proteins}, issn = {1091-6490}, doi = {10.1073/pnas.1525622113}, author = {Ghosh, Swagatha and Yu, Chi-Li and Ferraro, Daniel J and Sudha, Sai and Pal, Samir Kumar and Schaefer, Wayne F and Gibson, David T and Ramaswamy, S} }