title: Evaluating Quantum Dot Performance in Homogeneous FRET Immunoassays for Prostate Specific Antigen.
abstract: The integration of semiconductor quantum dots (QDs) into homogeneous Förster resonance energy transfer (FRET) immunoassay kits for clinical diagnostics can provide significant advantages concerning multiplexing and sensitivity. Here we present a facile and functional QD-antibody conjugation method using three commercially available QDs with different photoluminescence (PL) maxima (605 nm, 655 nm, and 705 nm). The QD-antibody conjugates were successfully applied for FRET immunoassays against prostate specific antigen (PSA) in 50 µL serum samples using Lumi4-Tb (Tb) antibody conjugates as FRET donors and time-gated PL detection on a KRYPTOR clinical plate reader. Förster distance and Tb donor background PL were directly related to the analytical sensitivity for PSA, which resulted in the lowest limits of detection for Tb-QD705 (2 nM), followed by Tb-QD655 (4 nM), and Tb-QD605 (23 nM). Duplexed PSA detection using the Tb-QD655 and Tb-QD705 FRET-pairs demonstrated the multiplexing ability of our immunoassays. Our results show that FRET based on QD acceptors is suitable for multiplexed and sensitive biomarker detection in clinical diagnostics.
authors: NanoBioPhotonics, Institut d'Electronique Fondamentale, Université Paris-Saclay, Université Paris-Sud, CNRS, 91405 Orsay, France. shashi.bhuckory@u-psud.fr.
authors: Shashi
authors: S
authors: Bhuckory
authors: NanoBioPhotonics, Institut d'Electronique Fondamentale, Université Paris-Saclay, Université Paris-Sud, CNRS, 91405 Orsay, France. olivier.lefebvre@u-psud.fr.
authors: Olivier
authors: O
authors: Lefebvre
authors: NanoBioPhotonics, Institut d'Electronique Fondamentale, Université Paris-Saclay, Université Paris-Sud, CNRS, 91405 Orsay, France. xue.qiu@u-psud.fr.
authors: Xue
authors: X
authors: Qiu
authors: NanoBioPhotonics, Institut d'Electronique Fondamentale, Université Paris-Saclay, Université Paris-Sud, CNRS, 91405 Orsay, France. kwegner@chem.ubc.ca.|Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada. kwegner@chem.ubc.ca.
authors: Karl David
authors: KD
authors: Wegner
authors: NanoBioPhotonics, Institut d'Electronique Fondamentale, Université Paris-Saclay, Université Paris-Sud, CNRS, 91405 Orsay, France. niko.hildebrandt@u-psud.fr.
authors: Niko
authors: N
authors: Hildebrandt
keywords: FRET; Qdots; TPSA; antibodies; bioconjugation; clinical diagnostics; homogeneous; immunoassay; serum; terbium; time-gating