Investigation on Co(II), Ni(II), Cu(II) and Zn(II) complexes derived from novel Nʹ-(3-hydroxybenzoyl)thiophene-2-carbohydrazide: structural characterization, electrochemical detection of biomolecules, molecular docking and biological evaluation

A series of transition metal (Co(II), Ni(II), Cu(II) and Zn(II)) complexes of novel Nʹ-(3-hydroxybenzoyl)thiophene-2-carbohydrazide ligand was synthesized and their structures were confirmed using 1H,13C NMR, IR, UV–visible, mass spectra, magnetic susceptibility, thermogravimetric analysis (TGA) and powder XRD techniques. The results obtained by the above mentioned techniques justified the promising bidendate coordination of the synthesized ligand and octahedral geometry was proposed to all the metal-coordinated compounds. In addition, with the help of cyclic voltammogram, the electrocatalysis ability of Co(II) HTC/GCE was examined utilizing different concentrations of dopamine (DA) and uric acid (UA). The Co(II)HTC/GCE sensor showed an excellent electrochemical performance with DA and UA at the concentration ranges 0.2 to 10 µML−1 and 0.1 to 0.8 µML−1 with detection limits (LOD) of 0.066 µML−1 and 0.333 µML−1 and sensitivities of 1.069 µAµM−1 cm−2 and 5.170 µAµM−1 cm−2 for DA and UA. Thus, the modified electrode exhibited better performance, extended shelf life, better reduplication and procreation. Further, bioefficacies of prepared ligand and its metal-coordinated compounds were examined against the bacteria (Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Bacillus subtilis) and fungi (Aspergillus niger and Candida albicans) strains using standard procedures. Moreover, the ligand and its metal complexes were evaluated for the antioxidant and cytotoxic studies on four different strain of cells (MCF-7, HeLa, K-562, and Vero) where Co(II) and Cu(II)coordinated compounds revealed admirable cytotoxity for MCF-7 and Hela cell lines. Lastly, molecular docking studies were performed on cancer receptors for the determination of binding mode of ligand and its transition metal complexes.