Plasmonic Circular Dichroism Study of Gold Nanorod-Quadruplex Nanobioconjugates

Document Type: Article

Authors

1 Protein Research Center, Shahid Beheshti University G.C., Velenjak Tehran, Iran

2 Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, 154-14115 Tehran, Iran

3 Department of Bioscience and Biotechnology, Malik-Ashtar University of Technology, Tehran, Iran

4 5- Laser and Plasma Research Institute, Shahid Beheshti University G.C., Velenjak Tehran. Iran.

5 5- Laser and Plasma Research Institute, Shahid Beheshti University G.C., Velenjak Tehran. Iran

6 Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, 154-14115 Tehran, Iran

Abstract

Circular dichroism spectroscopy is a simple way to study G-quadruplex structure and is very useful for monitoring the conformational changes in G-quadruplex structure induced by modifications of the environment. Plasmonic nanoparticles with localized surface plasmon resonance (LSPR) can create strong electromagnetic fields at the surface of plasmonic metals, which remarkably influence the optical properties of molecules. Plasmonic CD is a new CD signal which originates from the dipole–dipole interactions between surface plasmons of NPs and chiral biomolecules have received interest research in various fields of nanotechnology. In this paper we study the interaction between gold nanorods (GNR) and two types of G-quadruplex (parallel and antiparallel), to monitor the alterations in DNA conformation and plasmonic CD signal upon formation of GNR-quadruplex nanobioconjugate. The results from this study indicate the plasmonic CD signals in visible regions are more sensitive than Far-UV CD signals to detect the spatial conformational state of G-quadruplex-GNR nanobioconjugate. 

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