Figure 4.
(A) The UV-Vis absorption spectra of VB6-TMB system upon adding different concentrations of H2O2 (50.0–600.0 μM, from bottom to top); (B) Calibration plot of the absorbance versus the concentrations of H2O2 under the optimal conditions; (C) The corresponding digital photograph. The error bars represent the standard deviations of three independent measurements.