Excitation modalities for enhanced micro and nanoparticle imaging in a smartphone coupled 3D printed fluorescent...

Area of Science:

• Biomedical Imaging
• Microscopy Technology

Background:

• Smartphone fluorescent microscopes (SFM) offer cost-effective alternatives to benchtop microscopes for biomarker detection.
• Imaging sub-micron and nano-scale bioparticles with SFMs presents challenges due to performance requirements.

Purpose of the Study:

• To explore and compare the performance of different excitation modalities in SFMs for sub-micron particle imaging.
• To develop and evaluate distinct SFM variants based on excitation source positioning.

Main Methods:

• Three SFM variants were developed using parallel, perpendicular, and oblique excitation configurations.
• Performance was assessed using fluorescent beads (0.8-8.3 μm) across varying excitation voltages.
• Key performance metrics included signal-difference-to-noise ratio (SDNR) and contrast-to-noise ratio (CNR).

Main Results:

• SFMs with perpendicular and oblique excitation successfully imaged all bead sizes (0.8-8.3 μm).
• Oblique excitation yielded the highest SDNR and CNR, indicating superior image quality.
• Perpendicular excitation demonstrated the best power efficiency.

Conclusions:

• SFM variants with perpendicular and oblique excitation significantly enhance sub-micron imaging capabilities.
• Oblique excitation is optimal for image quality, while perpendicular excitation balances performance and power consumption.
• These findings are applicable to improving both SFM and benchtop microscopy performance for sub-micron applications.