Evaluating Quantum Dot Performance in Homogeneous FRET Immunoassays for Prostate Specific Antigen

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Homogeneous Förster resonance energy transfer (FRET) immunoassays offer potential for multiplexed and sensitive clinical diagnostics.
• Semiconductor quantum dots (QDs) present advantages as FRET acceptors due to their tunable photoluminescence and stability.

Purpose of the Study:

• To develop a facile QD-antibody conjugation method for FRET immunoassays.
• To evaluate the sensitivity and multiplexing capability of QD-based FRET immunoassays for biomarker detection.
• To assess the suitability of QD acceptors for clinical diagnostics.

Main Methods:

• Conjugation of three commercially available QDs (605 nm, 655 nm, 705 nm) to antibodies.
• Application of QD-antibody conjugates in homogeneous FRET immunoassays for prostate specific antigen (PSA) detection.
• Utilized Lumi4-Tb (Tb) antibody conjugates as FRET donors and time-gated photoluminescence detection.

Main Results:

• Successful QD-antibody conjugation and application in FRET immunoassays.
• Achieved low limits of detection for PSA: 2 nM (Tb-QD705), 4 nM (Tb-QD655), and 23 nM (Tb-QD605).
• Demonstrated multiplexed PSA detection using Tb-QD655 and Tb-QD705 FRET-pairs, showcasing assay multiplexing ability.

Conclusions:

• QD-based FRET immunoassays are suitable for sensitive and multiplexed biomarker detection.
• The developed QD-antibody conjugation method is facile and functional for clinical diagnostic applications.
• This approach holds promise for advancing clinical diagnostics with enhanced sensitivity and multiplexing capabilities.