Application |
Gold Nanoparticle Size Range |
Surface Chemistry |
Benefits |
Protein Conjugation |
5nm-100nm |
Standard (citrate) |
Quick |
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NHS |
Covalent conjugation to primary amines, increased conjugate stability, less non-specific protein binding. |
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Maleimide |
Covalent conjugation to thiols, increased conjugate stability, less non-specific protein binding.
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Carboxyl |
Covalent conjugation to primary amines, increased conjugate stability, less non-specific protein binding.
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Amine |
Conjugation of NHS and carboxyl ligands. |
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Ni-NTA |
Conjugation to histidine tags. Also useful for purification of histidine-tagged proteins and other ligands. |
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Azide |
Covalent conjugation to alkyne ligands through click chemistry. |
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Alkyne |
Covalent conjugation to azide ligands through click chemistry. |
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20nm-100nm |
DBCO |
Covalent conjugation to azide ligands through click chemistry without the need for a copper catalyst. More biologically compatible than typical alkyne click chemistry. |
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Streptavidin |
Conjugation to biotinylated ligands. |
Modification with thiolated ligands |
5nm-100nm |
Standard (citrate-coated) |
Classic starting material, no additional stabilizers added. |
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Stabilized (surfactant) |
Increased stability during functionalization but reduced binding kinetics. |
Oligonucleotide Conjugation |
5nm-20nm |
Standard (citrate) |
Ideal for conjugation of thiol-modified oligos to small particle sizes (5nm-20nm). Does not work well for larger particles. |
|
5nm-100nm |
OligoREADY |
Ideal for conjugation of thiol-modified oligos directly to the gold surface. |
|
5nm-100nm |
NHS |
Ideal for covalent conjugation of amine-modified oligos. Final conjugate will have a PEG-linker between oligo and gold surface. |
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5nm-100nm |
Maleimide |
Ideal for covalent conjugation of thiol-modified oligos.
Final conjugate will have a PEG-linker between oligo and gold surface.
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5nm-100nm |
Azide |
Ideal for covalent conjugation to alkyne-modified oligos through click chemistry. High yield and no non-specific binding. |
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5nm-100nm |
Alkyne |
Ideal for covalent conjugation to azide-modified oligos through click chemistry. High yield and no non-specific binding. |
|
20nm-100nm |
DBCO |
Ideal for covalent conjugation to azide-modified oligos through click chemistry. Much better suited for biological conditions than typical alkyne click chemistry. |
Immunoblotting/Western Blot |
5nm-20nm |
Secondary Antibody Gold Conjugates |
Colorimetric detection. Permanent label |
Immunohistochemistry |
5nm-40nm |
Secondary Antibody Gold Conjugates |
High contrast label |
Flow Cytometry |
70nm-400nm |
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Cellular Uptake |
30nm-80nm |
Transferrin Gold Conjugates |
Active uptake through endocytosis |
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Standard (citrate-coated) |
Non-specific cellular uptake |
Darkfield Microscopy |
50nm-100nm |
Gold Conjugates |
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Lateral Flow/Dip-Stick Assays |
20nm-80nm |
Standard (citrate-coated) |
Ideal for generation of gold conjugates through passive adsorption of antibodies to the gold nanoparticle surface. |
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NHS |
Ideal for covalent conjugation of antibodies to gold nanoparticles. |
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Maleimide |
Ideal for conjugation of thiol-modified ligands to gold nanoparticles. |
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Gold Conjugates |
Pre-made secondary antibody conjugates |
Vertical Flow |
20nm-40nm |
Standard (citrate-coated) |
Ideal for generation of gold conjugates through passive adsorption of antibodies to the gold nanoparticle surface.
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NHS |
Ideal for covalent conjugation of antibodies to gold nanoparticles.
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Maleimide |
Ideal for conjugation of thiol-modified ligands to gold nanoparticles.
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Gold Conjugates |
Pre-made secondary antibody conjugates. |
Tumor Targeting |
20nm-80nm |
Methyl (methoxy) Gold Nanoparticles |
Can in some cases be used for passive targeting of certain tumors in vivo. Inert material with low non-specific protein binding in serum. |
Light Microscopy |
5nm-10nm |
Gold Conjugates |
Ability to label tissue sections for both light and electron microscopy. Alternative to peroxidase and PAP-based stains. Sensitivity can be enhanced with silver enhancement techniques. |
ELISA |
5nm-30nm |
Gold Conjugates |
Colorimetric Detection |