title: Nanojacketing and dejacketing of ds-DNA: a nondestructive characterization of a nanojacketed sample by impedance spectroscopy.
abstract: A facile approach of nanojacketing DNA in intact conformation is evolved by the in situ polymerization of o-methoxyaniline (OMA) at 30 °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 kΩ, 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.
authors.affiliation: Indian Association for the Cultivation of Science , Jadavpur, Kolkata 700 032, India.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Nandi
authors.forename: Pratap
authors.initials: P
authors.lastname: Mukherjee
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Kundu
authors.forename: Arun K
authors.initials: AK
authors.lastname: Nandi
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002712:Chlorides / Q000737:chemistry; D002725:Chloroform / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D058266:Dielectric Spectroscopy / Q000379:methods*; D025802:Electric Capacitance; D017097:Electric Impedance; D004583:Electrons; D017612:Gold Compounds / Q000737:chemistry; D017613:Iodine Compounds / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D016877:Oxidants / Q000737:chemistry; D011073:Polyamines / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012996:Solutions; D013696:Temperature; D013950:Thymus Gland; D014867:Water / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D002712:Chlorides; D017612:Gold Compounds; D017613:Iodine Compounds; D016877:Oxidants; D011073:Polyamines; D011108:Polymers; D012996:Solutions; C543133:poly(2-methoxyaniline); D014867:Water; D002725:Chloroform; C024568:gold tetrachloride, acid; D004247:DNA; C003898:2-anisidine