Fluorescence Resonance Energy Transfer with Quantum Dots

Fluorescence resonance energy transfer (FRET) with quantum dots (QDs) exploits the non-radiative transfer of excitation energy from a fluorescent donor nanoparticle to a proximal acceptor molecule or nanoparticle. Quantum dots are semiconductor nanocrystals whose size-tuned emission spectra, high quantum yields and exceptional photostability make them superior donors in FRET systems. Efficient energy transfer requires close spatial proximity (typically 1–10 nm), substantial spectral overlap between donor emission and acceptor absorption, and favourable dipole orientation. Surface engineering of QDs with bioconjugation ligands or polymer coatings allows precise control of donor–acceptor distances and offers modular platforms for biosensing, live-cell imaging and diagnostics. The high brightness of QDs enhances sensitivity in detecting conformational changes, enzyme activities or molecular interactions, while their narrow emission bands facilitate multiplexed assays. Challenges include minimising direct acceptor excitation and managing potential cytotoxicity through benign compositions (for example indium phosphide cores) and robust surface passivation. Recent advances focus on cascade FRET architectures for solar energy harvesting, ratiometric pH and ion sensing in physiological conditions, and integration of time-gated detection schemes to suppress background autofluorescence. Overall, QD-based FRET represents a versatile toolkit for quantitative studies of dynamic processes at the nanoscale with global applications in chemical biology, medical diagnostics and environmental monitoring.

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Fluorescence Resonance Energy Transfer with Quantum Dots publication trend

The graph below shows the total number of articles in fluorescence resonance energy transfer with quantum dots across all publications each year (not limited to Nature Index journals).

Technical terms

Förster Resonance Energy Transfer (FRET): A distance-dependent non-radiative process by which energy is transferred from an excited donor fluorophore to an acceptor chromophore via dipole–dipole coupling.

Quantum Dot (QD): A semiconductor nanocrystal exhibiting size-tunable fluorescence emission, high quantum yield and remarkable resistance to photobleaching, used as a donor or acceptor in FRET systems.

Donor–Acceptor Pair: Two fluorophores or nanoparticles chosen for appropriate spectral overlap and separated by a few nanometres to enable efficient FRET.

Förster Distance (R₀): The characteristic separation at which FRET efficiency is 50 per cent, dependent on donor quantum yield, spectral overlap integral and relative dipole orientation.

Time-Gated Detection: A technique that delays fluorescence measurement after excitation to discriminate long-lived lanthanide or QD emissions from short-lived background autofluorescence, enhancing signal-to-noise ratio.

References

1. Förster Resonance Energy Transfer between Quantum Dot Donors and Quantum Dot Acceptors. Sensors (2015).
2. Single‐Nanoparticle Cell Barcoding by Tunable FRET from Lanthanides to Quantum Dots. Angewandte Chemie International Edition (2018).
3. Electrostatically driven resonance energy transfer in “cationic” biocompatible indium phosphide quantum dots. Chemical Science (2017).
4. A nanocrystal -based ratiometric pH sensor for natural pH ranges. Chemical Science (2012).
5. Quantum Dot–Based FRET Immunoassay for HER2 Using Ultrasmall Affinity Proteins. Small (2018).