Nanojacketing and Dejacketing of ds-DNA: A Nondestructive Characterization of a Nanojacketed Sample by Impedance Spectroscopy

作者：Nandi Sudipta; Mukherjee Pratap; Kundu Aniruddha; Nandi Arun K^*

来源：Journal of Physical Chemistry B, 2014, 118(10): 2649-2661.

DOI：10.1021/jp412373m

A facile approach of nanojacketing DNA in intact conformation is evolved by the in situ polymerization of o-methoxyaniline (OMA) at 30 degrees C using HAuCl4 as an oxidant and DNA as a soft template. It concomitantly produces poly(o-methoxyaniline) (POMA) and a Au nanojacket encapsulating the double stranded DNA (ds-DNA). The POMA chains remain adhered to the Au nanojacket, facilitating the dissolution of nanojacketed DNA (DNA-Au-POMA) in organic solvent without affecting its conformation. Digestion of the nanojacketed system with saturated iodine solution dejackets the ds-DNA with retention of its conformation, leaving the POMA nanotube. The nanojacketing and dejacketing phenomena are established by transmission electron microscopy (TEM), UV-vis spectroscopy, and CD spectroscopy, and the nanostructure is further characterized by FTIR, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The impedance study of the DNA-Au-POMA sample suggests the Cole-Cole plots at both the impedance and modulus planes and the values of capacitance and electron-transfer resistance of the material (R-et) are calculated to be 13.74 pF and 388 k Omega, respectively. The presence of a single Debye peak-in both the impedance and modulus vs frequency plots suggests an isotropic nature of the system, and the frequency dependent ac-conductivity suggests the presence of short-range translational and reorientational (localized) hopping of charge carriers at lower and higher frequency region.

• 出版日期2014-3-13