Microorganisms Cell conc., CFU/ml AuTiO2 10 ug/l Survival ratio, %* AuTiO2 20 ug/ml Survival ratio, %* E.coli 2.8×105 2.3×103 0.82 - - 1.0×104 2.2×102 2.2 - - 6.6×103 45 0.68 - - 2.7×105 - - 1.1×103 0.40 1.2×104 - - 90 0.75 6.2×103 - - ND 0.016 S.aureus 2.5×105 - - 1.3×103 0.52 1.3×104 - - 40 0.31 5.9×103 - - ND 0.017 ND: Not Detected *Ratio of cell concentration after 60 min in solar light to the corresponding initial concentration

Table 1: Effect of Escherichia coli, Staphylococcus aureus and AuTiO2 concentrations on its disinfection.