Synthesis, Characterization and DNA Binding Study of Silver N-Heterocyclic Carbene Complex [Bis (1,3-Dipentyl-1,3-Dihydro-2-Imidazole-2-Ylidene) Silver (I) hexafluorophosphate (V)] by Surface-Enhanced Raman Spectroscopy (SERS)

Abstract

The silver organometallic compounds favorably target DNA in cancerous cells and stop their growth by inhibiting DNA replication. Specific properties of these compounds help in their action as drugs and different changes occur in the structure of DNA. In-depth study of the binding mechanism of drugs is of potential use for novel drug synthesis. Surface-enhanced Raman spectroscopy (SERS) coupled with multivariate data analysis was employed to probe the interaction of silver N-heterocyclic carbene complex (drug) with DNA. In this study, silver N-heterocyclic carbene complex was synthesized and various concentrations were exposed to known concentrations of DNA. Silver nanoparticles were used for enhancement of Raman signals, which enabled sensitive detection and characterization of molecular changes occurring during binding process. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were applied to extract meaningful information from the spectral data. Changes in intensity and position of significant SERS signals were noted, which gave an indication of the bonding of the drug with DNA. The results reveal the strong intercalative binding of drug with nitrogenous bases of DNA. PCA and PLS-DA provide evidence for successful DNA-drug interaction.