Liquid photonic-molecule microlasers for ultrasensitive biosensing.

Area of Science:

• Biophotonics
• Biomedical Sciences
• Nanotechnology

Background:

• Droplet microlasers offer reconfigurable, sensitive, label-free biosensing capabilities.
• Simultaneously achieving low lasing thresholds, high spectral purity, and ultimate sensitivity in biosensors remains a challenge.

Purpose of the Study:

• To develop a versatile strategy for creating liquid photonic molecules (LPMs) that integrate low lasing thresholds, high spectral purity, and enhanced sensitivity.
• To engineer LPMs for dynamic tunability and superior biomolecular sensing performance.

Main Methods:

• Tailoring spectral Vernier overlap in size-mismatched droplets to achieve single-mode lasing.
• Employing a molecular isomerization strategy for dynamic tunability and spectral mode hopping.
• Leveraging self-referenced intensity response for enhanced biomolecular detection.

Main Results:

• Achieved single-mode lasing with a low threshold of approximately 610 nJ mm^-2.
• Demonstrated a nearly ten-fold enhancement in spectral sensitivity compared to single droplets.
• Obtained a three-orders-of-magnitude enhancement in biomolecular sensing with a detection limit of 30 aM and a nine-orders-of-magnitude dynamic range.

Conclusions:

• Liquid photonic molecules (LPMs) offer a promising platform for advanced bio-integrated liquid sensors.
• The developed LPM strategy successfully integrates critical properties for high-performance biosensing.
• This approach opens exciting prospects for diverse applications in biophotonics and biomedical sciences.