Stabilization of gold nanoparticles by thiolated tridentate nitrogen donor ligands and investigation of their DNA binding properties

In this study, three unique compounds: 2-[bis (2-(3, 5-dimethyl-1H-pyrazole-1-yl)ethyl) ethanethiol], 2-[bis (2-(3, 5-diphenyl-1H-pyrazol-1-yl) ethyl) amino] ethane thiol, and 2-[bis (2-pyridynylmethyl) amino] ethanethiol, were successfully synthesized via nucleophilic substitution reactions. The deprotonated forms of the compounds were used to synthesize a series of gold nanoparticles (AuNPs) via direct and ligand exchange methods. An interaction between these AuNPs and calf thymus DNA, demonstrated strong binding affinities, predominantly via intercalative interactions. This study projects the potential of these nanoparticles for DNA-targeted therapies and drug delivery systems. This provides a basis for further exploration into broader biomedical applications. • Three unique thiolated tridentate ligands have been synthesized via nucleophilic substitution reactions. • Gold nanoparticles (AuNPs) were synthesized using deprotonated ligands via direct and ligand exchange methods. • Strong DNA binding affinity of the AuNPs through intercalative interactions with calf thymus DNA was revealed. • Potential biomedical applications in DNA-targeted therapies and drug delivery systems are predicted.