Antimicrobial bionanocomposite–from precursors to the functional material in one simple step

Abstract

The mesoporous biosilica with unique 3D hierarchy in/organic functional groups is attractive material in terms of interfacial phenomena, and its high biocompatibility accelerates development in biomedical devices. In addition, their benefits also play a fundamental role in antimicrobial assessment. We hypothesize that the Diadesmis gallica biosilica surface acts as a biotemplate for AgCl and Au nanoparticle (NP) biosynthesis. Moreover, it exhibits antibacterial action human pathogenic bacteria. Nanoparticle biosynthesis was performed via a pure environmental-friendly, static, bottom-up in vitro regime. Minimal inhibitory concentrations evaluated systems with bionanocomposites for antibacterial efficiency in temporal time-dose-dependency. TEM and XRD depicts a biosilica “local sphere” which affects formation, stabilization and encapsulation of crystalline Au (9–27 nm) and AgCl (3–51 nm) NPs in one simple step. FTIR analysis reveals various functional in/organic groups, including Si–OH and polyamides. While both metal-bionanoparticles have analogical spherical shape with determined aggregation, ICP-AES analysis determined more effective 5.29 wt% Au NP formation than 1 wt% AgCl NPs. MIC analysis confirms that bionanocomposite with AgCl by concentration 0.014 mg/mL has the most effective antibacterial system for gram-positive and gram-negative bacteria strains. Although dual effect of Au/AgCl NP bionanocomposite has almost analogical influence on gram-positive bacteria, the synergic-antagonistic effect is irrelevant in this instance.