title: Label free fluorometric characterization of DNA interaction with cholate capped gold nanoparticles using ethidium bromide as a fluorescent probe.
abstract: We demonstrated label free ethidium bromide assisted characterization of DNA interaction with cholate capped AuNPs. Interactions between ss/ds DNA and AuNPs with two different lengths (0.5 and 0.85 kb) were analyzed through fluorescence spectrophotometer and agrose gel electrophoresis analysis. Further results were confirmed by UV-globally visible spectrophotometer, DLS and TEM. As 0.5 and 0.85 kb of ssDNA effectively interacted with AuNPs through the van der Waals interaction which consequently led to the prevention of salt induced aggregation, EtBr intercalations as well as fluorescence shift with less binding constant 0.098 and 0.108 μM, respectively. On the contrary, the same length of dsDNA (0.5 and 0.85 kb) not interacted with AuNPs which led to the NPs aggregation, EtBr intercalation as well as fluorescence shift with increased binding constant 0.166 and 0.599 μM, respectively. This approach helped to understand the mode of interactions of DNA with cholate capped AuNPs without any modifications in a simple method and the results could be readout through the naked eye under the UV transilluminator.
authors.affiliation: Department of Biotechnology, University of Madras, Guindy Campus, Chennai, 600 025, Tamil Nadu, India.
authors.forename: Gunasekaran
authors.initials: G
authors.lastname: Dharanivasan
authors.forename: Denison Michael Immanuel
authors.initials: DM
authors.lastname: Jesse
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Chandirasekar
authors.forename: Nagappan
authors.initials: N
authors.lastname: Rajendiran
authors.forename: Krishnan
authors.initials: K
authors.lastname: Kathiravan
mesh_terms: D020355:Cholates / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004996:Ethidium / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D005470:Fluorometry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D020355:Cholates; D005456:Fluorescent Dyes; D006046:Gold; D004247:DNA; D004996:Ethidium