Multiple Scattering-Enhanced Fluorescence Within Randomly Oriented Low-Index Polymer Nanofiber Sensors

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Fluorescence enhancement is vital for biological and chemical sensors.
• Current sensors use noble metals or high-index dielectrics, facing optical losses and complex fabrication.
• Low-index nanostructures offer advantages but struggle with weaker electric field enhancement.

Purpose of the Study:

• To design and fabricate a low-index, randomly oriented polyvinyl acetate (PVAc) nanofiber sensor.
• To leverage multiple scattering for enhanced surface fluorescence.
• To achieve a cost-effective and scalable fluorescence sensing platform.

Main Methods:

• Scalable electrospinning technique to produce randomly oriented PVAc nanofibers.
• Utilized multiple scattering within the disordered nanofiber network for fluorescence enhancement.
• Characterized sensor performance using rhodamine 6G and analyzed photoluminescence decay dynamics and random lasing.

Main Results:

• Achieved a high surface-enhanced fluorescence factor of 1170.
• Demonstrated a low detection limit of 7.24 fM for rhodamine 6G, surpassing existing sensors.
• Validated the role of multiple scattering in fluorescence enhancement via decay dynamics and random lasing.

Conclusions:

• The randomly oriented, low-index PVAc nanofiber sensor provides an efficient pathway for surface-enhanced fluorescence via multiple scattering.
• This scalable and cost-effective approach offers superior performance compared to traditional methods.
• The PVAc nanofiber platform is extendable to other low-index materials for diverse high-performance fluorescence sensing applications.