Time-Gated DNA Photonic Wires with Förster Resonance Energy Transfer Cascades Initiated by a Luminescent Terbium Donor

Abstract

Functional DNA nanotechnology is a rapidly growing area of research with many prospective photonic applications, including roles as wires and switches, logic operators, and smart biological probes and delivery vectors. Photonic wire constructs are one such example and comprise a Forster resonance energy transfer (FRET) cascade between fluorescent dyes arranged periodically along a DNA scaffold. To date, the majority of research on photonic wires has focused on setting new benchmarks for efficient energy transfer over more steps and across longer distances, using almost exclusively organic fluorescent dyes and strictly DNA structures. Here, we expand the range of materials utilized with DNA photonic wires by demonstrating the use of a luminescent terbium complex (Tb) as an initial donor for a four-step FRET cascade along a ∼15 nm long DNA/locked nucleic acid (LNA) photonic wire. The inclusion of LNA nucleotides increases the thermal stability of the photonic wires while the Tb affords time-gated emission m...