Abstract: The invention relates to a nanoscale antenna including a nucleic acid scaffold having a structure selected from the group consisting of a Holliday junction, a star, and a dendrimer; and a plurality of fluorophores attached to the scaffold and configured as a FRET cascade comprising at least three different types of fluorophores including at least one quantum dot, arranged with (a) a plurality of initial donor fluorophores fixed in exterior positions on the structure, (b) a terminal acceptor fluorophore fixed in a central position on the structure, and (c) a plurality of intermediate fluorophores fixed in positions on the scaffold between the initial acceptor fluorophores and the terminal acceptor fluorophores.

Abstract: A construct for detecting cellular membrane potential includes a nanoparticle operable as an electron donor; a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into the plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle; and an electron acceptor. The nanoparticle can be a quantum dot and the electron acceptor can be C60 fullerene. Emission correlates with cellular membrane potential.

Abstract: A nanoparticle (for example, quantum dot) serves as a substrate for immobilizing enzymes involved in consecutive reactions as a cascade. This results in a significant increase in the rate of catalysis as well as final product yield compared to non-immobilized enzymes.

Abstract: The invention relates to a nanoscale antenna including a nucleic acid scaffold having a structure selected from the group consisting of a Holliday junction, a star, and a dendrimer; and a plurality of fluorophores attached to the scaffold and configured as a FRET cascade comprising at least three different types of fluorophores, arranged with (a) a plurality of initial donor fluorophores fixed in exterior positions on the structure, (b) a terminal acceptor fluorophore fixed in a central position on the structure, and (c) a plurality of intermediate fluorophores fixed in positions on the scaffold between the initial acceptor fluorophores and the terminal acceptor fluorophores.

Abstract: Nanoparticles (and optionally a cargo such as a drug) can be delivered to cells by attaching just a single dendritic peptide to the nanoparticle. The dendritic peptide includes a polyhisitidine motif and a hinge and a spacer connecting the polyhistidine to a lysine-based dendritic wedge displaying at least two copies of a cell-penetrating peptide motif.

Abstract: A glass pipette such as an electrode for electrophysiological recording is coated with quantum dots. This greatly aids the ability to observe the glass pipette, particular in tissue as the quantum dots provide an excellent performance under two-photon illumination used to visualize objects at depths of hundreds of microns.

Abstract: Time-resolved nucleic acids include a long-lifetime FRET donor with an emission lifetime of at least one millisecond (such as a terbium complex), configured as a donor in a first FRET process, and at least one fluorescent dye with an emission lifetime of less than 100 nanoseconds configured as an acceptor in the FRET process. They can be configured as photonic wires, hybridization probes or beacons, and/or systems for computing logical operations.

Abstract: Described herein is a time-gated, two-step FRET relay effective to provide temporal transference of a prompt FRET pathway, or provide spectro-temporal encoding analytical signals and other information. A FRET relay assembly includes a long lifetime FRET donor (for example, a lanthanide complex), a semiconductor quantum dot (QD) configured as an intermediate acceptor/donor in FRET, and a fluorescent dye configured as a terminal FRET acceptor, wherein the long lifetime FRET donor has an excited state lifetime of at least one microsecond and the QD and fluorescent dye each have excited state lifetimes of less than 100 nanoseconds.

Abstract: A method of producing a protein includes providing a bacterial cell expressing both (a) a protein of interest fused to one of the SpyTag/SpyCatcher pair and (b) an outer membrane protein fused to the other of the SpyTag/SpyCatcher pair; causing the bacterial cell to express both of the protein of interest fusion and the outer membrane protein fusion in outer membrane vesicles; and purifying the outer membrane vesicles.

Abstract: A ligand design allows compact nanoparticle materials, such as quantum dots (QDs), with excellent colloidal stability over a wide range of pH and under high salt concentrations. Self-assembled biomolecular conjugates with QDs can be obtained which are stable in biological environments. Energy transfer with these ligands is maximized by minimizing distances between QDs/nanoparticles and donors/acceptors directly attached to the ligands or assembled on their surfaces.

Abstract: The invention relates to a nanoscale antenna including a nucleic acid scaffold having a structure selected from the group consisting of a Holliday junction, a star, and a dendrimer; and a plurality of fluorophores attached to the scaffold and configured as a FRET cascade comprising at least three different types of fluorophores, arranged with (a) a plurality of initial donor fluorophores fixed in exterior positions on the structure, (b) a terminal acceptor fluorophore fixed in a central position on the structure, and (c) a plurality of intermediate fluorophores fixed in positions on the scaffold between the initial acceptor fluorophores and the terminal acceptor fluorophores.

Abstract: A modular linker includes an inorganic binding entity having an affinity for a substantially inorganic substance, and an organic binding entity capable of binding with an organic substance covalently bonded thereto. The modular linker is capable of being stored in a stable condition for later use. The modular linker may be synthesized by modifying the inorganic binding entity to be covalently bonded to an organic binding entity and storing the modular linker in an inert environment from about a day up to at least 1 week. The modular linker may be conjugated to an organic substance and to a substantially inorganic substance in substantially a 1:1 ratio. The modular linker may have more than one organic binding entity covalently bonded to an inorganic binding entity or vice-versa. Also, a particular modular linker may have an organic binding entity capable of binding with a nucleic acid sequence.

Abstract: Described herein is a Förster (or fluorescence) resonance energy transfer (FRET) configuration with three energy transfer pathways between three luminescent components, where two of the energy transfer steps occur in sequence as a relay, and the first step of the relay is in competition with a third energy transfer process (energy transfer from the donor to the intermediary is in competition with energy transfer from the donor directly to the terminal acceptor).

Abstract: A glass pipette such as an electrode for electrophysiological recording is coated with quantum dots. This greatly aids the ability to observe the glass pipette, particular in tissue as the quantum dots provide an excellent performance under two-photon illumination used to visualize objects at depths of hundreds of microns.

Abstract: Quantum dots are modified with varying amounts of (a) a redox-active moiety effective to perform charge transfer quenching, and (b) a fluorescent dye effective to perform fluorescence resonance energy transfer (FRET), so that the modified quantum dots have a plurality of photophysical properties. The FRET and charge transfer pathways operate independently, providing for two channels of control for varying luminescence of quantum dots having the same innate properties.

Abstract: A peptide attached to a nanoparticles (such as quantum dots) selectively directs the nanoparticles to neurons in a tissue or organism.

Abstract: Described herein is a Förster (or fluorescence) resonance energy transfer (FRET) configuration with three energy transfer pathways between three luminescent components, where two of the energy transfer steps occur in sequence as a relay, and the first step of the relay is in competition with a third energy transfer process (energy transfer from the donor to the intermediary is in competition with energy transfer from the donor directly to the terminal acceptor).

Abstract: A peptide directs nanoparticles (such as quantum dots) to the plasma membrane of mammalian cells. A method of delivery of a nanoparticle to a plasma membrane of a cell includes providing to the cell a nanoparticle attached to a peptide configured to direct the nanoparticle the plasma membrane, and allowing the cell to take up the nanoparticle. The nanoparticle can be a FRET donor to an organic dye.

Abstract: Quantum dots are modified with varying amounts of (a) a redox-active moiety effective to perform charge transfer quenching, and (b) a fluorescent dye effective to perform fluorescence resonance energy transfer (FRET), so that the modified quantum dots have a plurality of photophysical properties. The FRET and charge transfer pathways operate independently, providing for two channels of control for varying luminescence of quantum dots having the same innate properties.

Abstract: Described are nucleic acids encoding a polypeptide for delivery of a nanoparticle to the cytosol, the peptide comprising: (a) a nanoparticle association domain, (b) a spacer domain, (c) an uptake domain, and (d) a vesicle escape domain, wherein the domains (a) through (d) appear in the same order as listed above, and wherein the peptide, upon addition of a non-hydrolyzable lipophilic moiety to the vesicle escape domain and binding to a nanoparticle, is effective to induce uptake of a nanoparticle by a cell and delivery of the nanoparticle to the cytosol of the cell. Also described are methods of delivery of a nanoparticle to the cytosol of a cell, the method comprising providing to a cell a nanoparticle attached to such a peptide. Exemplary nanoparticles include quantum dots.