Synthesis, characterization of penicillin G capped silver nanoconjugates to combat β-lactamase resistance in infectious microorganism

In the present study, a novel strategy was adopted to synthesize, β lactamase resistant penicillin G molecules by using the unique properties of silver nanoparticles. Ascorbic acid-stabilized spherical monodispersed silver nanoparticles were prepared by a simple chemical reaction. The formation processes of the silver nanoparticles were investigated by UV–vis spectroscopy and Atomic Force Microscopy (AFM). Free amine groups were introduced on the surface of native silver nanoparticles by coating a uniform layer of polyaniline and this was confirmed by FTIR spectroscopy and Scanning Electron Microscopy. Functionalized silver nanoparticles were then grafted to the C3 carboxyl group of the β lactam ring of penicillin G in the presence of N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDAC) with a conjugation yield of 213 μg mg−1. These novel silver penicillin G nanoconjugates showed a very good growth inhibition against both non-resistant Escherichia coli (gram negative) as well as toward β lactam resistant, E. coli (gram negative) and Staphylococcus aureus (gram positive).

► A novel method for quick and easy functionalization of silver nanoparticles.
► A novel chemistry for site specific coupling of silver nanoparticles with Penicillin G.
► A novel strategy to develop β lactamase resistant bactericidal material against the antibiotic resistant infectious pathogens.