1. Department of Physics &2. Astronomy , University of Toledo , Toledo, Ohio, 43606, USA;3. Division of Physical Chemistry Arrhenius Laboratory , University of Stockholm , S-106 91, Stockholm, SWEDEN
Abstract:
The observation of optical second harmonic generation (SHG) from wetspun films of Na-DNA is reported. The SHG signal is stronger at a relative humidity of 92% (corresponding to the B conformation of Na-DNA) than at low humidity of -33% (corresponding to a disordered conformation of Na-DNA). The strength of the SHG signal is also dependent on the orientation of the incident laser beam polarization with respect to the DNA helical axes.