Plasmonic bismuth coating for surface disinfection

Overview

This technology offers a novel approach to surface disinfection through a plasmonic coating based on bismuth nanoparticles. Unlike conventional disinfectants that require chemical agents or expensive precious metals, this coating harnesses light energy to generate reactive oxygen species (ROS) that actively destroy bacteria and viruses on coated surfaces. The use of bismuth provides significant advantages over traditional gold and silver plasmonic materials, including lower cost, reduced toxicity, and improved environmental compatibility.

The coating works by absorbing visible light through the surface plasmon resonance (SPR) effect in bismuth nanoparticles. This light absorption produces high-energy electrons and holes that generate highly reactive chemical radicals, which kill pathogens through oxidative damage to cell walls and internal structures. This approach provides a continuous, light-activated disinfection mechanism suitable for high-touch surfaces in healthcare facilities, public transportation, food processing environments, and consumer products.

Technical specifications

Core mechanism:

• Light absorption by plasmonic nanoparticles generates high-energy electrons and holes
• These carriers produce reactive oxygen species, including superoxide anions and hydroxyl radicals
• ROS trigger peroxidation of cell walls, damage internal organelles, and cause cell death

Material advantages:

• Bismuth-based nanoparticles replace expensive gold and silver plasmonic materials
• Environmentally friendly with very low toxicity
• Cost-effective due to bismuth abundance
• Exhibits surface plasmon resonance under visible light illumination

Research parameters:

• Particle size and shape controlled to tune localized surface plasmon resonance (LSPR) frequency
• Wavelength optimization for maximum disinfection efficiency
• Stable coating methods under development for practical application

Technology readiness level

This technology is at an early research stage with proof-of-concept validation. Previous research has demonstrated that bismuth nanostructures exhibit plasmonic properties and can produce ROS under visible light illumination. Plasmonic silver nanostructures have already shown effectiveness as light-activated disinfectants in published studies, establishing the underlying mechanism.

Future validation plans include establishing baseline performance using silver nanoparticles against Escherichia coli and Staphylococcus aureus, synthesizing and characterizing bismuth nanoparticles with controlled size and shape, identifying ROS types through ESR spectroscopy, optimizing wavelength-dependent disinfection efficiency, and developing stable coating methods suitable for real-world surfaces. The project is positioned for sponsored research collaboration to advance toward practical coating formulations and commercial applications.