A5044424478- Quantum Dots Synthesis And Properties
- Advanced biosensing and bioanalysis techniques
- Cold Atom Physics and Bose-Einstein Condensates
- Nanocluster Synthesis and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Molecular Junctions and Nanostructures
- Quantum optics and atomic interactions
- Synthetic Organic Chemistry Methods
- Strong Light-Matter Interactions
- Advanced Fluorescence Microscopy Techniques
- RNA Interference and Gene Delivery
- Electrochemical sensors and biosensors
- Biochemical and Structural Characterization
- Enzyme Catalysis and Immobilization
- Quantum Information and Cryptography
- Advanced Biosensing Techniques and Applications
- Chalcogenide Semiconductor Thin Films
- Photoreceptor and optogenetics research
- Atomic and Subatomic Physics Research
- Nanoparticle-Based Drug Delivery
- Neuroscience and Neural Engineering
- Organometallic Complex Synthesis and Catalysis
- Quantum Mechanics and Applications
- Biosensors and Analytical Detection
- Biotin and Related Studies
United States Naval Research Laboratory
2015-2025
Optical Sciences (United States)
2013-2025
United States Navy
2015-2025
Stony Brook University
2015-2020
Osteogenesis Imperfecta Foundation
2020
K Lab (United States)
2011-2016
Sotera Defense Solutions (United States)
2013
Scripps Research Institute
2010
Naval Research Laboratory Center for Bio/Molecular Science and Engineering
2010
University of Michigan
2004-2007
Efficient mid-infrared sources are of considerable general interest for gas analysis, remote sensing, and atmospheric monitoring, but existing technologies limited. Here, we report the synthesis first colloidal QDs having photoluminescence (PL) in mid-infrared. We show particle-size-tunable emission large (10-17 nm), quantum-confined, PbSe QDs, with efficient, narrow-bandwidth PL at energies as low 0.30 eV (4.1 mum). Applying two new synthetic routes, have achieved fine control QD size...
The unique photophysical properties of semiconductor quantum dot (QD) bioconjugates offer many advantages for active sensing, imaging, and optical diagnostics. In particular, QDs have been widely adopted as either donors or acceptors in Förster resonance energy transfer (FRET)-based assays biosensors. Here, we expand their utility by demonstrating that can function a simultaneous role within time-gated FRET relays. To achieve this configuration, the QD was used central nanoplatform...
Abstract Access to efficient enzymatic channeling is desired for improving all manner of designer biocatalysis. We demonstrate that enzymes constituting a multistep cascade can self-assemble with nanoparticle scaffolds into nanoclusters access substrate and improve catalytic flux by orders magnitude. Utilizing saccharification glycolytic quantum dots (QDs) as model system, nanoclustered-cascades incorporating from 4 10 steps are prototyped. Along confirming using classical experiments, its...
We present the design and synthesis of a new set poly(ethylene glycol) (PEG)-based ligands appended with multidentate anchoring groups test their ability to provide colloidal stability semiconductor quantum dots (QDs) gold nanoparticles (AuNPs) in extreme buffer conditions. The are made PEG segment two thioctic acid (TA) or dihydrolipoic (DHLA) groups, bis(TA)-PEG-OCH3 bis(DHLA)-PEG-OCH3. utilizes Michael addition create branch point at end chain combined carbodiimide-coupling attach TA per...
The nanoscale size and unique optical properties of semiconductor quantum dots (QDs) have made them attractive as central photoluminescent scaffolds for a variety biosensing platforms. In this report we functionalize QDs with dye-labeled peptides using two different linkage chemistries to yield Förster resonance energy transfer (FRET)-based sensors capable monitoring either enzymatic activity or ionic presence. first sensor targets the proteolytic caspase 3, key downstream effector...
The unique properties provided by hybrid semiconductor quantum dot (QD) bioconjugates continue to stimulate interest for many applications ranging from biosensing energy harvesting. Understanding both the structure and function of these composite materials is an important component in their development. Here, we compare architecture that results using two common self-assembly chemistries attach DNA QDs. modified display either a terminal biotin or oligohistidine peptidyl sequence was...
Combining the inherent scaffolding provided by DNA structure with spatial control over fluorophore positioning allows creation of DNA-based photonic wires capacity to transfer excitation energy distances greater than 150 Å. We demonstrate hybrid multifluorophore DNA-photonic that both self-assemble around semiconductor quantum dots (QDs) and exploit their unique photophysical properties. In this architecture, QDs function as central nanoscaffolds ultraviolet harvesting donors drive Förster...
Cell penetrating peptides facilitate efficient intracellular uptake of diverse materials ranging from small contrast agents to larger proteins and nanoparticles. However, a significant impediment remains in the subsequent compartmentalization/endosomal sequestration most these cargoes. Previous functional screening suggested that modular peptide originally designed deliver palmitoyl-protein thioesterase inhibitors neurons could mediate endosomal escape cultured cells. Here, we detail...
Recent studies show that polyvalent, ligand-modified nanoparticles provide significantly enhanced binding characteristics compared to isolated ligands. Here, we assess the ability of substrate-modified enzymatic activity. Energy transfer assays allowed quantitative, real-time measurement proteolytic digestion at polyvalent quantum dot-peptide conjugates. Enzymatic progress curves were analyzed using an integrated Michaelis–Menten (MM) formalism, revealing mechanistic details, including...
Botulinum neurotoxins (BoNTs) are extremely potent bacterial toxins that contaminate food supplies along with having a high potential for exploitation as bioterrorism agents. There is continuing need to rapidly and sensitively detect exposure these verify their active state, the latter directly affects diagnosis helps provide effective treatments. We investigate use of semiconductor quantum dot (QD)−peptide Förster resonance energy transfer (FRET) assemblies monitor activity BoNT serotype A...
The growing utility of semiconductor quantum dots (QDs) in biochemical and cellular research necessitates, turn, continuous development surface functionalizing ligands to optimize their performance for ever more challenging diverse biological applications. Here, we describe a new class multifunctional polymeric as stable, compact high affinity alternative multidentate thiolated molecules. are designed with poly(acrylic acid) backbone where pyridines used anchoring groups that not sensitive...
The intrinsic properties of quantum dots (QDs) and the growing ability to interface them controllably with living cells has far-reaching potential applications in probing cellular processes such as membrane action potential. We demonstrate that an electric field typical those found neuronal membranes results suppression QD photoluminescence (PL) and, for first time, PL is able track profile a firing neuron millisecond time resolution. This effect shown be connected electric-field-driven...
Bismuth has been investigated as a potential n-type dopant in hybrid lead halide perovskites, but its behavior all-inorganic perovskites such CsPbBr3 not thoroughly characterized. We show that Bi behaves deep defect and gives rise to broad near-infrared emission, similar phenomenon previously reported CsPbBr3. Using inverse temperature crystallization, we synthesized series of Bi-doped crystals quantified their concentrations by inductively coupled plasma optical emission spectroscopy....
Quantum dots (QDs) are loaded with a series of peptides and proteins increasing size, including <20 residue peptide, myoglobin, mCherry, maltose binding protein, which together cover range masses from <2.2 to approximately 44 kDa. Conjugation the surface dihydrolipoic acid-functionalized QDs is facilitated by polyhistidine metal affinity coordination. Increasing ratios dye-labeled self-assembled then bioconjugates separated analyzed using agarose gel electrophoresis. Fluorescent...
Semiconductor quantum dots (QDs) are attractive probes for optical sensing and imaging due to their unique photophysical attributes nanoscale size. In particular, the development of assays biosensors based on QDs Förster resonance energy transfer (FRET) continues be a prominent focus research. Here, we demonstrate application as simultaneous donors acceptors in time-gated FRET relay multiplexed detection protease activity. contrast current state-of-the-art, which uses multiple colors QDs,...
We demonstrate controlled in vivo bioconjugation of a targeted intracellular protein to semiconductor quantum dots (QDs). Metal-affinity driven coordination oligohistidine-appended proteins for chelated divalent cations was exploited facilitate this interaction. Monomeric mCherry red fluorescent recombinantly engineered express an N-terminal hexahistidine sequence expressed from eukaryotic plasmid vector following transfection into COS-1 cells. QDs solubilized with carboxylated polymeric...
We report the development of a quantum dot (QD)–peptide–fullerene (C60) electron transfer (ET)-based nanobioconjugate for visualization membrane potential in living cells. The bioconjugate is composed (1) central QD donor, (2) membrane-inserting peptidyl linker, and (3) C60 acceptor. photoexcited donor engages ET with acceptor, resulting quenching photoluminescence (PL) that tracks positively number moieties arrayed around QD. nature QD-capping ligand also modulates efficiency; neutral...
As a specific example of the enhancement enzymatic activity that can be induced by nanoparticles, we investigate hydrolysis organophosphate paraoxon phosphotriesterase (PTE) when latter is displayed on semiconductor quantum dots (QDs). PTE conjugation to QDs underwent extensive characterization including structural simulations, electrophoretic mobility shift assays, and dynamic light scattering confirm orientational ratiometric control over enzyme display which appears necessary for...
Luminescent semiconductor ∼9.5 nm nanoparticles (quantum dots: QDs) have intrinsic physiochemical and optical properties which enable us to begin understand the mechanisms of nanoparticle mediated chemical/drug delivery. Here, we demonstrate ability CdSe/ZnS core/shell QDs surface functionalized with a zwitterionic compact ligand deliver cell-penetrating lipopeptide developing chick embryo brain without any apparent toxicity. Functionalized were conjugated palmitoylated peptide...