Prism coupler and microscopic investigations of DNA films

Anna Samoc; Zbigniew Galewski; Marek Samoc; James G. Grote

doi:10.1117/12.737248

10 September 2007 Prism coupler and microscopic investigations of DNA films

Anna Samoc, Zbigniew Galewski, Marek Samoc, James G. Grote

Proceedings Volume 6646, Nanobiotronics; 664607 (2007) https://doi.org/10.1117/12.737248
Event: NanoScience + Engineering, 2007, San Diego, California, United States

Abstract

DNA is a polyelectrolyte capable of forming thin films with interesting optical properties. We investigated refractive indices and optical anisotropy of films of the native, sodium ion-based DNA (Na-DNA) and DNA bearing the cetyltrimethylammonium ion (DNA-CTMA) using a prism coupler technique. The light polarization direction was either parallel (n_TE) or perpendicular to the surface plane of the films (n_TM). The index values and the birefringence of DNA films vary considerably depending on the type of the counter-ion, the film fabrication method and the relative humidity (RH) of the environment. A high negative birefringence in films of Na-DNA, n_TE-n_TM = -0.03 at an RH ~ 55 %, was measured in solution-cast films, indicating that the optically anisotropic DNA molecules are aligned in the plane parallel to the film surface. Refractive indices of DNA-CTMA thin films were smaller and more isotropic than those for films of Na-DNA polymer. The prism coupler reflectance curves showed a hysteresis of the index values when the RH of a DNA-CTMA film environment varied. Polarization microscopy studies showed liquid-crystalline textures at the edges of Na-DNA and DNA-CTMA films.

Citation Download Citation

Anna Samoc, Zbigniew Galewski, Marek Samoc, and James G. Grote "Prism coupler and microscopic investigations of DNA films", Proc. SPIE 6646, Nanobiotronics, 664607 (10 September 2007); https://doi.org/10.1117/12.737248

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available