Stable antibody attachment prevents desorption under challenging assay conditions (e.g., high salt, surfactants).
Carboxyl-functionalized gold nanoparticles for covalent conjugation
Nano Flow™ carboxyl-functionalized gold nanoparticles are designed for covalent conjugation of antibodies, proteins, and other biomolecules. Their carboxyl (-COOH) surface chemistry allows for stable and oriented binding via EDC/NHS activation, improving conjugate robustness and long-term stability. Produced under ISO 9001:2015 certification, Nano Flow carboxyl colloids are available from small R&D volumes to large-scale batches, supporting diagnostic developers at every stage.
Why choose Nano Flow carboxyl-functionalized nanoparticles?
Particle size selection for assay formats
| Assay format | Recommended sizes | Key benefits | ||
|---|---|---|---|---|
| Competitive assays | 20 nm – 40 nm | Smaller surface area per particle → fewer antibodies coupled → improved sensitivity in competitive formats | ||
| Sandwich assays | 40 nm – 60 nm* – 80 nm | Larger surface area → higher antibody loading → stronger signal and enhanced sensitivity | ||
| *60 nm available on request for large-volume projects. | ||||
| Specification | 20 nm Carboxyl colloids (NF-CG20) | 40 nm Carboxyl colloids (NF-CG40) | 60 nm Carboxyl colloids (NF-CG60) | 80 nm Carboxyl colloids (NF-CG80) |
|---|---|---|---|---|
| Size | 20 ± 3 nm | 40 ± 3 nm | 60 ± 4 nm | 80 ± 5 nm |
| Functional group | -COOH | -COOH | -COOH | -COOH |
| Sphericity | ≥ 99% | ≥ 99% | ≥ 99% | ≥ 99% |
| Odd shapes per 100 particles | ≤ 1 | ≤ 1 | ≤ 1 | ≤ 1 |
| CV on particle sizes | < 15% | < 13% | < 10% | < 10% |
| Suspension | Water | Water | Water | Water |
| Single batch scale | from mL to >10 L | from mL to >10 L | from mL to >10 L | from mL to >10 L |
| Stability | 18 months | 18 months | 18 months | 18 months |
All Nano Flow gold nanoparticles are supplied with a Certificate of Analysis, including TEM, DLS, and UV-Vis spectroscopy data, to ensure compliance with specifications and reproducibility across batches.
