Biofilm interfacial acidity evaluation by pH-Responsive luminescent nanoparticle films

Area of Science:

• Biomaterials Science
• Nanotechnology
• Microbiology

Background:

• Bacterial biofilms on medical devices cause persistent infections.
• Extracellular polymeric substances (EPS) hinder antibiotic penetration.
• Biofilms create acidic microenvironments, offering a therapeutic target.

Purpose of the Study:

• To develop a high-throughput method for measuring biofilm acidity at the medical device interface.
• To create a pH-responsive nanomaterial for biofilm acidity detection.
• To investigate the influence of bacterial species on biofilm acidity.

Main Methods:

• Fabrication of luminescent, pH-responsive carbonated hydroxyapatite nanoparticles doped with Eu3+.
• In-situ deposition of nanoparticles onto substrates for biofilm growth.
• Fluorometric analysis of nanoparticle luminescence changes due to pH-induced carbonate removal.
• Cultivation and analysis of clinically relevant bacterial biofilms.

Main Results:

• The developed nanoparticles exhibit pH-responsive luminescence, correlating with acidity.
• The system successfully quantifies interfacial acidity of biofilms.
• Biofilm acidity varies significantly between different bacterial species and strains, independent of biomass.

Conclusions:

• A novel all-inorganic nanoparticle system enables fluorometric determination of biofilm acidity.
• This technology provides a new tool for characterizing the biofilm microenvironment.
• Understanding biofilm acidity is crucial for developing targeted anti-biofilm strategies.