Ultrasensitive optical imaging with lanthanide lumiphores

Area of Science:

• Biomedical imaging
• Optical microscopy
• Biophysics

Background:

• Lanthanide chelates offer potential for ultrasensitive biological detection due to their long emission lifetimes.
• Current lanthanide microscopy techniques are limited by low photon flux, inefficient excitation, and background luminescence, hindering sensitivity.
• Existing methods do not surpass conventional fluorescence microscopy sensitivity.

Purpose of the Study:

• To address fundamental limitations in lanthanide microscopy.
• To develop a novel imaging modality for enhanced lanthanide detection.
• To improve signal intensity and signal-to-background ratios for biological imaging.

Main Methods:

• Introduced transreflected illumination with luminescence resonance energy transfer (trLRET).
• Overcame challenges of low photon flux, inefficient excitation, and background luminescence.
• Applied trLRET to visualize endogenous protein expression in zebrafish embryos.

Main Results:

• trLRET increased time-integrated signal intensities of lanthanide lumiphores by 170-fold.
• trLRET improved signal-to-background ratios by 75-fold.
• Demonstrated an order-of-magnitude increase in detection sensitivity compared to epifluorescence microscopy.

Conclusions:

• trLRET significantly enhances lanthanide imaging sensitivity and signal quality.
• The new modality enables ultrasensitive, autofluorescence-free biological imaging.
• trLRET can be used for visualizing endogenous proteins and detecting molecular interactions in vivo.