Reduced background autofluorescence for cell imaging using nanodiamonds and lanthanide chelates

Area of Science:

• Biomedical Engineering
• Molecular Imaging
• Cell Biology

Background:

• Autofluorescence in bio-imaging interferes with targeted fluorophores, hindering cellular process monitoring.
• Developing methods to reduce background autofluorescence is crucial for advanced bio-imaging applications.

Purpose of the Study:

• To introduce and evaluate two novel techniques for reducing cellular autofluorescence interference in bio-imaging.
• To demonstrate background-free fluorescent staining of E-selectin in endothelial cells using these new methods.

Main Methods:

• Utilized fluorescent nanodiamonds (FNDs) with nitrogen vacancy centers emitting at near-infrared wavelengths.
• Employed europium-chelating tags with long fluorescence lifetimes to overcome short autofluorescence lifetimes.
• Targeted E-selectin, an inflammation-activated glycoprotein, in fixed endothelial cells.

Main Results:

• Both FND and Europium-based staining significantly reduced competition with cellular autofluorescence.
• 30 nm nanodiamonds coated with E-selectin antibodies provided the most sensitive detection.
• A 40-fold increase in E-selectin intensity was detected in inflamed cells.

Conclusions:

• Novel FND and Europium-based methods enhance bio-imaging by minimizing autofluorescence.
• These techniques improve the detection sensitivity of specific biomolecules, such as E-selectin.
• Background-free imaging is achievable, advancing cellular and molecular analysis.