AgAuSe QDs

Cat. No.: A1452639

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

Overview

AgAuSe QDs (AgAuSe) is a near infrared (NIR) fluorescent quantum dots (QDs), with a bright emission from 820 to 1170 nm. AgAuSe QDs can be used for the research in biomedical imaging and NIR devices.

Specifications

Storage

Store at -20°C

Shipped In

Ice chest + Ice pads

This product requires cold chain shipping. Ground and other economy services are not available.

Application Protocols

No item-specific validated protocols are provided for this product. The following generalized procedures (literature-based) can serve as starting points; optimize to your system and refer to the CoA for any lot-specific guidance.

• Preparing a working dispersion:
  1. Warm the stock to ambient temperature to avoid moisture condensation. 2) Vortex gently and, if compatible, briefly sonicate (bath sonicator, ≤5 min) to redisperse any settled particles. 3) Filter through a 0.2 µm solvent-compatible filter to remove dust/aggregates.
• Steady-state photoluminescence (PL):
  • Prepare an optically dilute sample (Abs < 0.1). Excite at a fixed wavelength away from strong re-absorption. Record excitation/emission spectra; correct for solvent/background.
• TEM sample prep:
  • Drop-cast 3–5 µL of dilute dispersion onto carbon-coated copper grids; wick excess after 30–60 s; dry under inert gas and protect from light.
• Aqueous bioconjugation (if carboxylate/amine ligands are present; general):
  • Activate carboxyl groups with EDC/NHS at pH 5.5–6.5; add amine-bearing ligand/biomolecule; incubate 0.5–2 h; quench and purify via centrifugal filtration/SEC. Avoid competing amines/thiols in buffers.
• Thin-film deposition:
  • Spin-coat from toluene/chlorobenzene; perform post-deposition ligand exchange with short bifunctional ligands to enhance conductivity as needed.

Always perform small-scale pilot runs to validate colloidal stability, optical response, and compatibility with matrices/buffers before scaling.

Biological Roles

This is a synthetic nanomaterial, not a biomolecule, and it has no native role in biological pathways. The following points are general, literature-based considerations for interactions with biological systems when AgAuSe QDs are used in research contexts:

• Cellular interactions: Surface chemistry dictates protein corona formation, cellular uptake pathways (clathrin/caveolae/macropinocytosis), and intracellular trafficking. Hydrophilic, zwitterionic, or PEGylated shells can reduce nonspecific adsorption.
• Optical roles: Size/composition-tunable emission and high extinction enable use as fluorescent labels or reporters in microscopy and flow cytometry. Excitation can often be performed at a fixed wavelength with size-tuned emission readouts.
• Energy/charge transfer: QDs participate in FRET, photoinduced electron transfer (PET), and plasmon–exciton coupling (with Ag/Au content), enabling lifetime-based biosensing schemes.
• Biocompatibility factors: Core composition (Ag/Au/Se), shelling, and ligand robustness influence ion release and ROS generation under illumination. Thorough cytotoxicity assessment is recommended for each formulation and application.
• Clearance/stability (in vitro systems): Hydrodynamic size and surface charge control colloidal stability in buffers and serum; aggregation can alter apparent bioresponses and signal.

No clinical/therapeutic claims are made. Any biological use should be performed in accordance with institutional biosafety approvals, and performance/toxicity must be empirically determined for the specific lot and surface chemistry. Item-specific biological data: Not specified for this item; refer to CoA/Spec Sheet.

Buffer Applications

AgAuSe QDs themselves are not buffering agents. However, for applications involving aqueous dispersions or bioassays, buffer choice critically influences colloidal stability and photophysics (general literature guidance):

• Recommended buffer characteristics (for hydrophilic QDs):
  • pH near neutrality (pH 6.8–8.0) to minimize ligand protonation/deprotonation that can induce aggregation.
  • Moderate to low ionic strength (e.g., 10–50 mM) to limit electrostatic screening; higher salt may be tolerated with strong steric ligands (PEG, zwitterions).
  • Additives: 0.01–0.05% nonionic surfactant (Tween-20, Pluronic) can suppress nonspecific adsorption.
• Common systems: PBS, HEPES, or Tris buffers (10–50 mM); avoid primary amines during EDC/NHS coupling steps. For metal-affinity or thiol-responsive assays, avoid competing thiols (DTT, βME) that can displace ligands and quench PL.
• Filtration and sterilization: Use 0.22 µm filters suitable for nanoparticles; pre-block filters with buffer + 0.01% surfactant to reduce loss.
• Light and oxygen: Protect from strong light during preparation; deoxygenate when measuring excited-state lifetimes to reduce quenching.

Item-specific buffer compatibility is Not specified for this item; refer to CoA/Spec Sheet. Always verify colloidal stability by DLS/UV–Vis before critical experiments.

Green Alternatives

Selection of quantum dots has environmental and safety implications due to heavy-metal content and solvent systems.

• Considerations (general):

  • Ag/Au/Se composition involves precious/heavy elements. While Au/Ag reduce concerns associated with Cd/Pb toxicity, selenium-containing nanomaterials still require controlled disposal and may present aquatic toxicity risks.
  • Common synthesis/processing uses high-boiling aromatics or chlorinated solvents; greener media can reduce VOC and toxicity footprints.

• Alternative materials (literature, general):

  • Indium phosphide (InP), copper indium sulfide/selenide (CIS/CISe), and carbon dots as cadmium/lead-free emitters. Tradeoffs include broader emission, lower PLQY without advanced passivation, and different band-edge positions.
  • Plasmonic enhancement can be achieved with separate Au/Ag nanostructures coupled to benign semiconductors rather than alloying.

• Greener processing strategies:

  • Use cyclopentyl methyl ether (CPME), anisole, or 2-methyltetrahydrofuran (2-MeTHF) instead of chlorinated solvents where colloidal stability allows.
  • Implement ligand exchange to water-soluble, zwitterionic or PEGylated ligands enabling aqueous processing and reducing VOCs.
  • Recycle/centrifuge solvents and implement closed-loop purification (antisolvent precipitation with greener alcohols if compatible).

• Summary table (general):

  • AgAuSe QDs: high photophysical tunability; heavy metals; require careful waste handling.
  • InP/CIS QDs: lower toxicity profile; may need complex passivation; sometimes broader FWHM.
  • Carbon dots: metal-free, greener; typically lower extinction coefficients and different emission mechanisms.

Pharmaceutical Uses

This product is offered for research use only and is not intended for diagnostic, therapeutic, or clinical applications.

• Formulation/excipient status: Not applicable; no pharmacopeial monograph is associated with AgAuSe QDs. Item-specific regulatory status: Not specified for this item; refer to CoA/Spec Sheet.
• Process development research (general): Quantum dots may be used as optical tracers or surrogates in formulation/process studies (e.g., monitoring mixing, film formation, or as model nanoparticles for filtration and sterilization studies). Such uses remain non-clinical and exploratory.
• Compatibility considerations in formulation research:
  • Ligand shell integrity under shear, heat, and lyophilization stresses.
  • Interactions with polymers/surfactants in films, inks, or coatings; potential migration and aggregation on curing.
  • Extractables/leachables from packaging in contact with nanodispersions.

No claims are made regarding therapeutic benefit, safety, or suitability for human/animal use. For any work near regulated spaces, conduct independent risk assessments and obtain necessary approvals.

Physical Properties

Item-specific physicochemical constants for this nanoparticle product are not provided.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Dispersed/solid form: Not specified for this item; refer to CoA/Spec Sheet.
• Density, melting point, boiling point, refractive index: Not applicable/Not specified for colloidal nanoparticles; refer to CoA/Spec Sheet.
• Solubility/dispersion media: Depends on surface ligands (e.g., nonpolar solvents for hydrophobic ligands; water/buffer for hydrophilic ligands). Specific ligand/solvent system: Not specified for this item; refer to CoA/Spec Sheet.
• Photophysical properties (literature, general for Ag/Au–chalcogenide QDs):
  • Quantum confinement yields size-tunable absorption onsets and photoluminescence (PL) spanning visible to near-infrared, depending on composition/size/defects.
  • Ag/Au incorporation can introduce plasmonic features (broad visible/NIR extinction) and modify radiative/nonradiative rates via alloying or core–shell coupling.
  • PL quantum yields vary widely (few % to >50%) depending on synthesis and passivation; item-specific PLQY: Not specified for this item; refer to CoA/Spec Sheet.
• Colloidal stability (general): Sensitive to ionic strength, pH (for ionizable ligands), and competitive ligands; aggregation elevates scattering and quenches PL.
• Thermal/photostability (general): Improved by strong X-type ligands (thiol/carboxylate) and inert-environment storage; photo-oxidation of chalcogenide surfaces can red-shift/blue-shift features and reduce PL.
• Zeta potential and hydrodynamic size (DLS): Not specified for this item; refer to CoA/Spec Sheet.

Quality & Grades

• Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
• What defines quality for AgAuSe QDs (general, for professional buyers):
  • Size and size dispersity (FWHM of absorption/PL; TEM histograms). Narrow dispersity improves spectral purity and device uniformity.
  • Composition/stoichiometry control (Ag:Au:Se ratios via ICP-OES/EDX) determines band structure and plasmon-exciton coupling.
  • Crystal phase and defect density (XRD, HRTEM) correlate with PL quantum yield and charge transport.
  • Surface chemistry identity and coverage (XPS, TGA, FTIR); ligand type dictates solvent compatibility and bioconjugation routes.
  • Optical metrics: Absorption onset/first exciton, PL peak position, FWHM, PLQY, lifetime; suppression of trap emission.
  • Colloidal cleanliness (low free ligand/solvent residues) and batch-to-batch reproducibility.
• Stabilizers/ligands: Not specified for this item; refer to CoA/Spec Sheet. In general, X-type thiols/carboxylates and L-type amines/phosphines are used; their presence impacts long-term stability and conjugation chemistry.
• Documentation: For method validation and regulated workflows, request the batch CoA including ICP composition, TEM size distribution, PLQY, solvent/ligand identity, and residual metal/halide assays if available.
• Fit-for-purpose selection: Choose lots with emissions/excitons aligned to your optical setup and with ligand shells compatible with your matrix (polymer, solvent, or aqueous buffer).

Reaction & Applications

This product class (AgAuSe quantum dots) is primarily used as functional nanomaterials rather than stoichiometric reagents. Key application domains (literature/general):

• Photoluminescence and spectroscopy: Size/composition-tunable emission for imaging probes, FRET donors/acceptors, and calibration standards. Alloying with Au/Ag can modulate radiative/nonradiative rates and introduce plasmon–exciton coupling.
• Photocatalysis: Visible/NIR-light-driven redox catalysis (e.g., dye degradation models, organic transformations) leveraging chalcogenide band edges; noble-metal content can enhance charge separation and surface reaction kinetics.
• Sensing: Changes in PL intensity/lifetime or scattering upon analyte binding (e.g., thiol/halide quenching, heavy-metal ion interactions). Surface functionalization enables selective chemosensing.
• Optoelectronics: Active layers in photodetectors, solar conversion, and nonlinear optics. Film casting with cross-linkable ligands or inorganic shells enhances stability.
• Surface-enhanced optical effects: Au/Ag domains support plasmonic enhancement of local fields, enabling boosted PL or SERS substrates when assembled appropriately.

Practical notes:

• Maintain ligand integrity to preserve quantum yield; avoid aggressive polar solvents unless exchanging ligands deliberately.
• Degas dispersions for sensitive photophysics; oxygen can quench excitons and oxidize surfaces.
• For photocatalysis, quantify photon flux and monitor catalyst photobleaching; include dark controls and radical scavengers to probe mechanism.
• For sensing/imaging, validate linearity, limit of detection, and matrix effects; calibrate with matched blanks to decouple scattering.

Reaction Conditions

No item-specific synthesis or processing conditions are provided. The following are general, literature-based conditions for preparation, modification, and use of Ag/Au–chalcogenide QDs:

• Colloidal synthesis (hot-injection/heat-up, literature):
  • Precursors: Metal salts (acetates/halides) or metal–thiolates with selenium sources (trioctylphosphine selenide, silyl selenides) in high-boiling coordinating solvents (oleylamine, trioctylphosphine oxide, octadecene).
  • Temperatures: ~120–250°C depending on ligand/precursor reactivity; inert atmosphere (N2/Ar) with rigorous degassing.
  • Growth control: Reaction time from seconds to tens of minutes; quench by cooling/addition of solvent; purification via antisolvent precipitation (e.g., ethanol/isopropanol) and redispersion in nonpolar solvent.
• Ligand exchange (to polar media, literature):
  • Phase transfer with thiolated PEGs, multidentate carboxylates, or zwitterionic ligands in DMF/DMSO/water mixtures; monitor PL to avoid quenching.
  • Post-exchange purification by size-exclusion chromatography or centrifugal filtration to remove excess ligands.
• Film formation (literature):
  • Spin-coating/casting from toluene/chlorobenzene; post-deposition exchanges with short ligands (ethanedithiol) or inorganic treatments (NH4SCN, halides) to improve conductivity.
• Photophysical measurements:
  • Use optically dilute solutions (Abs < 0.1 at excitation wavelength) to avoid inner-filter and re-absorption.

Yields, exact times, and stoichiometries are system- and ligand-dependent and should be optimized experimentally. For this catalog item, specific protocols/conditions are Not specified; refer to CoA/Spec Sheet and SDS.

Safety & Handling

• GHS classification, signal word, hazard statements, pictograms: Not specified for this item; refer to SDS.
• General hazards (nanoparticle and composition-related, literature/general):
  • Nanoparticles may pose inhalation hazards; avoid aerosol generation. Handle in a fume hood or enclosure.
  • Contains heavy metals (Ag, Au) and selenium; treat as potentially toxic to aquatic life and as hazardous waste. Prevent environmental release.
  • Organic capping ligands and dispersants may be flammable or irritant depending on solvent system.
• Personal protective equipment (PPE): Lab coat, safety glasses, and appropriate chemically resistant gloves (e.g., nitrile). Use respiratory protection if aerosol risk cannot be eliminated (per institutional policy/SDS).
• Engineering controls: Work in a chemical fume hood or nanoparticle handling enclosure; use closed containers and secondary containment.
• Storage incompatibilities (general): Segregate from strong oxidizers and acids/bases that can strip ligands or release H2Se/selenides under extreme conditions. Keep away from light if photo-oxidation is a concern.
• First aid (overview; defer to SDS):
  • Inhalation: Move to fresh air; seek medical attention if symptoms persist.
  • Skin/eye contact: Rinse with water for ≥15 minutes; remove contaminated clothing; seek medical attention for irritation.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical attention.
• Spill/cleanup: Avoid dry sweeping; use damp disposable wipes or HEPA-filtered vacuum designed for nanoparticles. Dispose of waste as hazardous heavy-metal waste per regulations.
• SDS: Consult the product SDS for authoritative, item-specific safety information.

Solvent Selection

Because solvent compatibility of QDs is governed by their surface ligands, solvent selection must match the ligand polarity and binding chemistry.

• Item-specific dispersant/ligands: Not specified for this item; refer to CoA/Spec Sheet.
• General guidance (literature):
  • Hydrophobic (oleylamine/oleate/alkylthiol capped): Disperse in nonpolar media (hexane, toluene, chloroform, chlorobenzene) and select higher-boiling aromatics (toluene, chlorobenzene, o-dichlorobenzene) for film casting and device processing.
  • Amphiphilic/ionic (thiol-PEG, carboxylates, amines): Disperse in water and common biological buffers; include low ionic strength or steric stabilizers to deter aggregation.
  • Coordinating solvents (pyridine, DMF, DMSO) can perform ligand exchange or assist dispersion of partially polar shells; monitor for PL quenching.
• Dielectric/polarity considerations (general): Higher dielectric solvents screen Coulombic interactions and can reduce interparticle aggregation; nonpolar solvents preserve high PL in hydrophobic dots by minimizing surface solvation.
• When to choose alternatives:
  • For photonics/LED inks, chlorobenzene or toluene balance volatility and film quality.
  • For aqueous bioassays, buffered saline with surfactant (e.g., 0.01–0.05% Tween-20) can stabilize hydrophilic dots.
• Practical tips:
  • Avoid alcohols with hydrophobic dots (can trigger precipitation).
  • Filter dispersions (0.2 µm PTFE or PES, solvent-appropriate) to remove dust/aggregates.
  • Minimize exposure to strong Lewis bases or halides unless intentionally exchanging ligands.

Storage & Reconstitution

• Storage conditions (from Product Data): Store at -20°C. Protect from light. Maintain containers tightly closed to minimize solvent loss and oxidation. Minimize freeze–thaw cycles.
• Shipped in (from Product Data): Ice chest + Ice pads.
• Appearance and physical state: Not specified for this item; refer to CoA/Spec Sheet (dispersion vs dry powder/paste not specified).
• Stability considerations (general):
  • Avoid repeated thawing; if frequent access is needed, create aliquots under inert atmosphere when feasible.
  • Oxygen, moisture, and light can degrade chalcogenide surfaces and ligands, reducing PL and altering dispersibility.
• Reconstitution/redisperison (general guidance; item-specific solvent/ligand Not specified):
  • If supplied as a dried solid/film: Reconstitute in an appropriate solvent matched to ligand polarity (e.g., toluene/hexane for hydrophobic ligands; water or buffer for hydrophilic shells). Start with small volumes, gentle vortexing, and brief bath sonication. Filter (0.2 µm) before use.
  • If supplied as a frozen dispersion: Thaw at 4–10°C, equilibrate to room temperature, invert to mix, and inspect for precipitation. If needed, mild sonication can aid redispersion. Do not heat above ligand/solvent limits.
• Shelf-life and specifications: Not specified for this item; refer to CoA/Spec Sheet.
• Research use note (from Product Data): For research use only.

Structure & Identity

AgAuSe QDs are ternary metal–chalcogenide quantum dots consisting of silver (Ag), gold (Au), and selenium (Se) in a nanoscale crystalline semiconductor/plasmonic composition. As quantum dots, their identity is defined by core composition, crystal phase, particle size, and surface-capping ligands rather than a single small-molecule formula.

• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet (note: nanoparticle materials are polydisperse; no single MW applies).
• CAS, CID, InChIKey, SMILES: Not applicable to polydisperse nanoparticle preparations; Not specified for this item; refer to CoA/Spec Sheet.
• Structural features (general/literature):
  • Ternary chalcogenide lattice containing Ag–Au–Se; may be alloyed or core–shell-like depending on synthesis (literature, not item-specific).
  • Typical QD diameters range from ~2–10 nm with quantum-confinement-dependent optical properties (literature).
  • Surface-stabilized by organic ligands (e.g., oleylamine, thiols, carboxylates) or polymer/bioligands after ligand exchange (literature). Specific ligand for this item: Not specified for this item; refer to CoA/Spec Sheet.
  • Crystallography often derivative of chalcopyrite or related Ag–Au–Se phases; exact phase and stoichiometry determine band structure (literature).
• 2D structural description: Spheroidal/crystalline nanocrystals comprising a close-packed arrangement of Ag/Au cations with Se anions, passivated by an organic ligand shell that controls colloidal stability and surface chemistry. No discrete small-molecule connectivity (hence no line notation identifiers).

Synthetic Utility

While AgAuSe QDs are not typical stoichiometric reagents, they offer utility as nanostructured catalysts and functional building blocks in materials synthesis (literature/general):

• Heterogeneous/photocatalysis: Noble-metal-containing chalcogenide QDs can catalyze reductions/oxidations under visible light, leveraging interband transitions and surface states. Au/Ag domains facilitate electron trapping and promote multi-electron processes.
• Seeded growth/templates: Serve as seeds for overcoating (e.g., ZnS, silica) to tune surface passivation, or as plasmonic–semiconductor hybrids in hierarchical assemblies.
• Thin-film/self-assembly: Ligand engineering enables close packing into superlattices for optoelectronic films; post-deposition ligand exchange (short bifunctional ligands, halides, or chalcogenidometallates) improves charge transport.
• Bioconjugation scaffold: Carboxylate/amine/thiol-functional shells permit attachment of peptides, oligonucleotides, or polymers for sensing constructs (general guidance; item-specific ligand availability Not specified for this item; refer to CoA/Spec Sheet).

Retrosynthetic/design perspective:

• Band-edge positioning can be designed by varying Ag:Au:Se ratios and particle size to match redox potentials of target transformations.
• Surface Lewis acidity/basicity (metal vs chalcogen-rich facets) guides choice of ligands and catalysis co-catalysts.

Quality metrics for synthetic utility include narrow size dispersity, robust ligand shells, and reproducible surface stoichiometry to ensure consistent catalytic/assembly behavior.

Target Specificity

Not applicable. This product is a nanoparticle material (AgAuSe quantum dots), not an antibody, enzyme, or affinity reagent. No antigen/epitope specificity, clone, isotype, or species reactivity applies to this item.