@article {1606, title = {Highly Responsive Fluorescent Assemblies Allow for Unique, Multiparametric Sensing of the Phospholipid Membrane Environment.}, journal = {Chemistry}, volume = {25}, year = {2019}, month = {2019 Jan 28}, pages = {1507-1514}, abstract = {

Despite decades-long extensive research, probes that provide a comprehensive description of the lipid membrane microenvironment are still lacking. Here, a "smart" pyrene-terpyridine probe for multiparametric sensing of lipid membranes is reported. The complexity of the associated local microenvironment can be described by the distinct features of the probe fluorescence. The self-assembly of the probe molecules in phospholipid bilayers was sensitive to membrane order and phase state. The self-assembled probes showed a unique emission, influenced by dye-dye interactions and excited-state charge transfer. Moreover, this emission was sensitive to interfacial hydration, with very specific changes in emission wavelengths and fluorescence lifetimes upon variation of lipid compositions and properties. In parallel, changes in the lipid order and hydration affected the ground-state interactions in the dye aggregates and, thus, could be measured through ratiometric changes in the excitation and emission readouts. In addition, fluorescence anisotropy measurements provided another way to study the nature of dye aggregates in lipid bilayers. Overall, this report demonstrates how multiple aspects of the membrane microenvironment can be sensed through the unique fluorescence signatures of this "smart" probe in lipid membranes, and it establishes a new paradigm in lipid-membrane sensing.

}, keywords = {Fluorescence Polarization, Fluorescent Dyes, Lipid Bilayers, Phospholipids, Pyrenes, Spectrometry, Fluorescence, Water}, issn = {1521-3765}, doi = {10.1002/chem.201803627}, author = {Gulyani, Akash and Dey, Nilanjan and Bhattacharya, Santanu} } @article {1190, title = {A unique self-assembly-driven probe for sensing a lipid bilayer: ratiometric probing of vesicle to micelle transition}, journal = {Chem. Commun.}, volume = {54}, year = {2018}, pages = {5122-5125}, abstract = {

An amphiphilic pyrene-terpyridine (Pytpy) probe forms novel{,} fluorescent nanoaggregates in phospholipid membranes. This unique membrane-driven self-assembly of Pytpy shows large Stokes shifts and long-lived fluorescent states and efficiently reports on vesicle-micelle transition through ratiometric changes. Strikingly{,} Pytpy can even distinguish between bilayer-like domains and more-dynamic micelle-like {{\textquoteright}}rim{{\textquoteright}} phases that co-exist in mixed assemblies (bicelles).

}, doi = {10.1039/C8CC01635F}, url = {http://dx.doi.org/10.1039/C8CC01635F}, author = {Gulyani, Akash and Dey, Nilanjan and Bhattacharya, Santanu} }