Fig. 4: Detection of enzyme-mimicking activity and steady-state kinetics of M_xV₂O₅·nH₂O.

A UV-vis absorption spectra of oxTMB in the presence of H₂O₂ with M_xV₂O₅·nH₂O, V₂O₅ powder, V₂O₅ nanobelt, respectively. B The generation of ·OH testified by ESR spectra of M_xV₂O₅·nH₂O, V₂O₅ powder, V₂O₅ nanobelt in the presence of H₂O₂. C Absorbance of oxTMB in the presence of H₂O₂ and M_xV₂O₅·nH₂O/V₂O₅ nanobelt after adding isopropanol. n  =  3 experimental replicates. Data are presented as mean values  ±  SD. The data were analyzed by using a one-sided unpaired t-test. ****P < 0.0001. D Time-dependent absorbance of oxTMB (a), reaction rate (b) with different concentrations of TMB and fixed concentrations of MgVO/H₂O₂, and the corresponding double reciprocal (Lineweaver-Burk) plots (inset). E Time-dependent absorbance of oxTMB (a), reaction rate (b) with different concentrations of H₂O₂ and fixed concentrations of MgVO/TMB, and the corresponding double reciprocal (Lineweaver-Burk) plots (inset). n  =  3 experimental replicates (D, E (b)). Data are presented as mean values  ±  SD (D, E (b)). V_max and K_m values of M_xV₂O₅·nH₂O/V₂O₅ nanobelt towards to TMB (F) and (G) H₂O₂. H The comparison of the TON and V_max values of M_xV₂O₅·nH₂O with other recently reported catalysts. I The comparison of the relative catalytic activity of M_xV₂O₅·nH₂O and synthesized peroxidase mimics. n  =  3 experimental replicates. Data are presented as mean values  ±  SD. Data were analyzed by one-way ANOVA with Turkey’s multiple comparisons test, ns represented no statistical difference, ****P < 0.0001.