Multiplexed Nucleic Acid Hybridization Assays Using Single-FRET-Pair Distance-Tuning

Multiplexed photoluminescence (PL) detection plays an important role in chemical and biological sensing. Here, it is shown that time-gated (TG) detection of a single terbium-donor-based Forster resonance energy transfer (FRET) pair can be used to selectively quantify low nanomolar concentrations of multiple DNAs or microRNAs in a single sample. This study demonstrates the applicability of single-TG-FRETpair multiplexing for molecular (Tb-to-dye) and nanoparticle (Tb-to-quantum-dot) biosensing. Both systems use acceptor-sensitization and donor-quenching for quantifying biomolecular recognition and modification of the donor-acceptor distance for tuning the PL decays. TG intensity detection provides extremely low background noise and a quick and simple one-step assay format. Single-TG-FRET-pair multiplexing can be combined with spectral and spatial resolution, paving the way for biosensing with unprecedented high-order multiplexing capabilities.