Bactericidal Effect of Silica Gel-Supported Porphyrinatophosphorus(V)Catalysts on Escherichia coli under Visible-Light Irradiation

摘要

Dihydroxo-and dimethoxo(tetraphenylporphyrinato)phosphorus(V)complexes ([P(OR)_2tpp]~+)were immobilized on silica-gel powder affording a visible-light drNen photocatalyst ([P(OR)_2tpp]/SiO_2;1).Bactericidal effect of complexes la (R = H)and 1b (R = Me)on Escherichia coli were investigated under visible-light irradiation.In the case of complex la,the amount of E.coli decreased linearly versus the irradiation time,showing that the bactericidal reaction obeyed zero-order kinetics.Adsorption of bacteria on the catalyst is thought to be a key pathway by analysis according to Michaelis-Menten's equation.Complex la was more effectNe for sterilization than complex lb.Stabilities of the [P(OR)_2tpp]~+immobilized on silica-gel beads (2)were investigated in aqueous CaCl_2 and NaCl solutions.The elution of the [P(OH)_2tpp]~+chromophore from complex 2a (R = H)was faster than it was from complex 2b (R = Me).