Chiral nano heterobimetallic DNA receptors: In vitro binding studies, cleavage activity and DNA condensation studies (TEM and AFM imaging)

A new chiral nano heterobimetallic Co-Sn and Zn-Sn complexes were designed and thoroughly characterized by various spectroscopic viz H-1, C-13, Sn-119 NMR, ESI-MS, magnetic moment, analytical and visualization techniques. The electronic absorption and spectroscopic data reveal that the Co(II) ion exhibits a square pyramidal geometry. Sn-119 NMR spectral data and powered XRD measurements support the hexa-coordinated geometry of the Sn(IV) atom. The binding studies of the heterobimetallic Co-Sn complex with CT-DNA were carried out by using various biophysical techniques viz UV-vis absorption, emission spectroscopy and cyclic voltammetric measurements, recommended predominantly electrostatic mode of interaction of the complex with CT-DNA. The gel electrophoretic patterns of supercoiled pBR322 DNA with varying concentration of the Co-Sn complex exhibit an ability to cleave DNA and follow hydrolytic pathway mechanism. Furthermore, the application of chiral nano heterobimetallic Co-Sn complex as DNA gene transporter was evaluated by DNA condensation and ascertained by employing the visualization techniques i.e. TEM and AFM, which illustrated that the Co-Sn complex induces the condensation of CT-DNA to a particulate nanostructure. (C) 2012 Elsevier B.V. All rights reserved.