Fig. 1

Schematic structure of rutoside (R) and methylene blue (MB) (a). Methylene blue UV/vis spectrum variations in the presence of different concentrations of rutoside (b). Alternation in absorbance at 620 nm (dimeric form of MB) (black circle) and 668 nm (monomeric form of MB) (black circle) by increasing rutoside (c). Benesi-Hildebrand plot for interaction of methylene blue (10 µg/mL) (dimeric form of MB) (red diamond suit) and 668 nm (monomeric form of MB) (blue diamond suit) with rutoside at pH = 7 and at 25 °C (d). R Rutoside, MB methylene blue