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 1H, 13C, 119Sn 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. 119Sn 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.