title: Excited-state solvation and proton transfer dynamics of DAPI in biomimetics and genomic DNA.
abstract: The fluorescent probe DAPI (4',6-diamidino-2-phenylindole) is an efficient DNA binder. Studies on the DAPI-DNA complexes show that the probe exhibits a wide variety of interactions of different strengths and specificities with DNA. Recently the probe has been used to report the environmental dynamics of a DNA minor groove. However, the use of the probe as a solvation reporter in restricted environments is not straightforward. This is due to the presence of two competing relaxation processes (intramolecular proton transfer and solvation stabilization) in the excited state, which can lead to erroneous interpretation of the observed excited-state dynamics. In this study, the possibility of using DAPI to unambiguously report the environmental dynamics in restricted environments including DNA is explored. The dynamics of the probe is studied in bulk solvents, biomimetics like micelles and reverse micelles, and genomic DNA using steady-state and picosecond-resolved fluorescence spectroscopies.
authors.affiliation: Unit for Nano Science & Technology, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India.
authors.forename: Debapriya
authors.initials: D
authors.lastname: Banerjee
authors.forename: Samir Kumar
authors.initials: SK
authors.lastname: Pal
mesh_terms: D000042:Absorption; D000818:Animals; D032701:Biomimetics; D004247:DNA / Q000378:metabolism*; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism; D023281:Genomics; D007211:Indoles / Q000737:chemistry* / Q000378:metabolism; D008297:Male; D011522:Protons; D012474:Salmon; D012997:Solvents / Q000737:chemistry*; D013737:Testis; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D007211:Indoles; D011522:Protons; D012997:Solvents; C007293:DAPI; D004247:DNA