Figure 2.

MDR E. coli viability assessment by MTT assay. (a) MDR-1 E. coli viability and (b) MDR-2 E. coli viability after treatment with GO, AgNP, GO-Ag, mixture of GO and AgNP (GO + AgNP) at different final concentrations in LB broth. +, ++, +++ represent different concentrations for different groups. GO (+, 1.5 µg ml⁻¹; ++, 3 µg ml⁻¹; +++, 6 µg ml⁻¹); AgNP (+, 2 µg ml⁻¹; ++, 4 µg ml⁻¹; +++, 8 µg ml⁻¹); GO+AgNP mixture (+, 1.5 µg ml⁻¹ GO and 2 µg ml⁻¹ AgNP; ++, 3 µg ml⁻¹ GO and 4 µg ml⁻¹ AgNP; +++, 6 µg ml⁻¹ GO and 8 µg ml⁻¹ AgNP), GO-Ag (+, 3.5 µg ml⁻¹; ++, 7 µg ml⁻¹; +++, 14 µg ml⁻¹). Error bars represent standard deviations (n ≥ 3). *p < 0.05, **p < 0.01, ***p < 0.001.