Surface Plasmon-Enhanced fluorescence of Spirulina microalgae via triangular silver nanoparticles

Area of Science:

• Biophotonics
• Materials Science
• Biomedical Imaging

Background:

• Spirulina microalgae possess natural chromophores for photonics and biomedical imaging.
• Challenges like low quantum yield and aggregation limit Spirulina's fluorescence applications.
• Plasmonic nanoparticles (NPs) offer a method to enhance fluorescence properties.

Purpose of the Study:

• To improve the fluorescence properties of Spirulina microalgae using plasmonic nanoparticles.
• To investigate the effect of silver triangular nanoparticles (Ag-TNPs) on Spirulina's photoluminescence.
• To explore the potential of Spirulina-Ag-TNP composites for biophotonic sensing.

Main Methods:

• Synthesized triangular silver nanoparticles (Ag-TNPs).
• Combined Ag-TNPs with Spirulina microalgae.
• Analyzed nanoparticle-microalgae interaction using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX).
• Evaluated fluorescence enhancement based on spectral overlap and NP concentration.

Main Results:

• Ag-TNPs exhibited plasmon resonance in the visible spectrum, aligning with Spirulina's fluorescence.
• SEM and EDX confirmed Ag-TNP adherence to Spirulina, increasing with NP density.
• Optimal Ag-TNP concentrations enhanced fluorescence, while excessive amounts caused quenching.
• A complex fluorescence behavior was observed in Spirulina-Ag-TNP composites.

Conclusions:

• The combination of Spirulina and Ag-TNPs shows potential for enhancing fluorescence.
• Careful control of Ag-TNP concentration is crucial for optimal fluorescence amplification.
• Spirulina-Ag-TNP composites are suitable for developing biophotonic sensors monitoring photoluminescence changes.