Green Carboxyl Fluorescent Nanoparticle (167–500 nm) – Catalog #B2026047

Green Carboxyl Fluorescent Nanoparticles (Catalog #B2026047) are colloidal suspensions of nanometer-scale particles with bright green fluorescence and reactive carboxyl (–COOH) surface groups. Supplied as 10 mL, these nanoparticles combine ease of conjugation with high quantum yield and excellent photostability, making them suitable for cell labeling, tracking, imaging, and detection workflows. The carboxyl groups enable rapid, stable attachment of proteins, antibodies, peptides, and other targeting molecules via standard carbodiimide (EDC/NHS) or amine coupling chemistries.

Scientific Overview

Fluorescent nanoparticles offer significant advantages over traditional dyes and proteins: bright, photostable fluorescence with low photobleaching; small size for easy cellular uptake or co-localization with target molecules; and quantifiable optical properties for detection and sorting. Carboxyl-functionalized nanoparticles are particularly versatile because the reactive carboxyl groups can be activated (via EDC/NHS or direct carbodiimide coupling) to form amide bonds with amine-containing molecules.

The 167–500 nm size range is ideal for applications requiring sufficient signal intensity while maintaining nanoscale properties for cell and tissue penetration. Green fluorescence (~500/520 nm excitation/emission) is well-separated from autofluorescence and compatible with standard green channel detectors on fluorescence microscopes and flow cytometers.

Key applications include:

• Direct cell labeling for flow cytometry and microscopy
• Conjugation to antibodies for immunofluorescence assays
• Protein tagging and affinity tracking
• Multiplexed detection in combination with other colors
• Particle tracking for cell dynamics and transport studies

Usage & Handling Guidance

Store at 2–8°C and protect from prolonged light exposure. Before use, mix gently to ensure uniform suspension; do not vortex vigorously, as this may cause aggregation.

• Bioconjugation: Activate carboxyl groups with EDC/NHS in MES buffer (pH 5–6) for 15–30 minutes, then incubate with your target protein (pH 7–8) for 1–4 hours at room temperature or 4°C overnight.
• Washing: After conjugation, centrifuge briefly (if needed) and wash with PBS or storage buffer to remove unreacted particles.
• Cell labeling: Incubate conjugated nanoparticles with cells at 4°C (for surface labeling) or 37°C (for internalization) for 30 minutes to several hours, depending on the target and application.
• Detection: Use standard green filter sets (ex ~488 nm, em ~520 nm) on fluorescence microscopes or flow cytometers.

What You Get

• 10 mL of green-emitting carboxyl-functionalized nanoparticles (167–500 nm)
• Bright, photostable fluorescence ready for immediate use or bioconjugation
• Reactive carboxyl groups for protein and antibody coupling
• Compatible with standard fluorescence microscopy and flow cytometry instrumentation
• For research use only (RUO)

Why Researchers Choose It

• High quantum yield and excellent photostability
• Carboxyl surface chemistry enables rapid protein coupling
• Suitable for both fixed and live-cell imaging
• Ideal for multiplexing when combined with other fluorophore colors
• Easier to detect and quantify than small-molecule dyes

Frequently Asked Questions (FAQ)

• What is the typical fluorescence intensity?
  This depends on the specific particle composition and batch. Intensity is generally higher than small-molecule dyes and lower-quantum-yield quantum dots. Request the COA/TDS for lot-specific photophysical characterization.
• Can I use EDC/NHS coupling?
  Yes. EDC (N-ethyl-N′-carbodiimide) activates carboxyl groups for amine coupling; NHS increases the reaction efficiency. This is the standard approach for protein conjugation.
• How do I prevent particle aggregation?
  Mix gently, avoid vortexing, and keep particles in suspension. Store at 2–8°C and use sterile, pyrogen-free buffers.
• Are these particles appropriate for live-cell imaging?
  Yes, provided they are non-toxic at your working concentration and the conjugate does not interfere with cellular function. Test in your system before large-scale experiments.
• Can I get a COA or TDS?
  Yes. Request a quote or contact us and we will provide available lot documentation.

References

• Qian J, Wang Y, Gao X, Zhan Q, Xu Z, He S. Carboxyl-functionalized and bio-conjugated silica-coated quantum dots as targeting probes for cell imaging. J Nanosci Nanotechnol. 2010;10(3):1668-75.
• Jana NR, Erathodiyil N, Jiang J, Ying JY. Cysteine-functionalized polyaspartic acid: a polymer for coating and bioconjugation of nanoparticles and quantum dots. Langmuir. 2010;26(9):6503-7.
• Ho YP, Leong KW. Quantum dot-based theranostics. Nanoscale. 2010;2(1):60-8.