Abstract
Silver nanoparticles were produced with AgF as the starting Ag(I) salt, with pectin as the reductant and protecting agent. While the obtained nanoparticles (pAgNP-F) have the same dimensional and physicochemical properties as those already described by us and obtained from AgNO(3)and pectin (pAgNP-N), the silver nanoparticles from AgF display an increased antibacterial activity againstE. coliPHL628 andStaphylococcus epidermidis RP62A(S. epidermidisRP62A), both as planktonic strains and as their biofilms with respect to pAgNP-N. In particular, a comparison of the antimicrobial and antibiofilm action of pAgNP-F has been carried out with pAgNP-N, pAgNP-N and added NaF, pure AgNO3, pure AgF, AgNO(3)and added NaF and pure NaNO(3)and NaF salts. By also measuring the concentration of the Ag(+)cation released by pAgNP-F and pAgNP-N, we were able to unravel the separate contributions of each potential antibacterial agent, observing an evident synergy between p-AgNP and the F(-)anion: the F(-)anion increases the antibacterial power of the p-AgNP solutions even when F(-)is just 10 mu M, a concentration at which F(-)alone (i.e., as its Na(+)salt) is completely ineffective.