•Molecular thermodynamic association parameters for the bulk and nano-vanadyl sulfate were determined by the conductometry in aqueous solution at various temperatures for understanding the mechanism of oxidation and reduction of various vanadyl species in solutions.•From the interaction of the bulk & nano VOSO4 with Orange G, in the instance of the 1:1 complex as opposed to the 1:2 (VOSO4/Orange G) complex in water as the solvent, the estimated Kf and ΔGf were higher.•Molecular docking of VOSO4 versus 7 jwy of amino acid of covid-19 allows us to better understand the probable modes of engagement that provide more clarity on how well the molecules exert bioactivity towards the target.•VOSO4 show greater antioxidant behavior than the stander ascorbic acid with the same concentration. Molecular thermodynamic association parameters for the bulk and nano-vanadyl sulfate were determined by the conductometry in aqueous solution at various temperatures. The thermodynamic parameters for complex formation 1:1, 1:2 (M/L) between bulk & nano vanadyl with Orange G were also determined by the conductivity measurements. From the interaction of the bulk & nano vanadyl sulfate (VOSO4) with Orange G, in the instance of the 1:1 complex as opposed to the 1:2 (VOSO4/Orange G) complex in water as the solvent, the estimated Kf and ΔGf were higher. When the temperature rises, the complex formation constants decrease. The molecular complexation's negative ΔGf values show that the production of molecular complexes is spontaneous and that it gets higher as the temperature rises. The molecular complexation is an endothermic and entropy-controlled reaction, which is supported by the negative values of ΔHf. Molecular docking of vanadyl sulfate versus 7 jwy of amino acid of covid-19 allows us to better understand the probable modes of engagement and binding affinities of the targeted molecule (vanadyl sulfate), that provide more clarity on how well the molecules exert bioactivity towards the target. The vanadyl sulfate show greater antioxidant behavior than the stander ascorbic acid with the same concentration. Also, the oxygen radicals ranging from 1.1 to 1.4 V which are reduced giving reduction peaks (broad) facilitating the use of vanadyl sulfate as a strong antioxidant solution.