A novel thermal decomposition approach to synthesize hydroxyapatite–silver nanocomposites and their antibacterial action against GFP-expressing antibiotic resistant E. coli

A novel thermal decomposition approach to synthesize hydroxyapatite–silver (Hap-Ag) nanocomposites has been reported. The nanocomposites were characterized by X-ray diffraction, field emission scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy and diffuse reflectance spectroscopy techniques. Antibacterial activity studies for the nanocomposites were explored using a new rapid access method employing recombinant green fluorescent protein (GFP) expressing antibiotic resistant Escherichia coli (E. coli). The antibacterial activity was studied by visual turbidity analysis, optical density analysis, fluorescence spectroscopy and microscopy. The mechanism of bactericidal action of the nanocomposites on E. coli was investigated using atomic force microscopy, and TEM analysis. Excellent bactericidal activity at low concentration of the nanocomposites was observed which may allow their use in the production of microbial contamination free prosthetics.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Hydroxyapatite–Ag nanocomposites has been synthesized by a novel thermal decomposition method. ► Green fluorescent protein expressing antibiotic resistant E. coli used to test antibacterial activity. ► The nanocomposites show excellent bactericidal activity with low minimum killing concentration.