Carbonate terminated nanoparticles have a surface that is the closest to “bare” of all our particles. Similar to citrate, carbonate molecules provide a negative zeta potential across a wide range of pH. However, instead of three carboxylic acid groups like citrate (MW 189), carbonate has only a single carboxyl group and has a lower molecular weight (MW of CO32– is 60.0). The smaller size and reduced effective charge of the molecule makes it easier to displace resulting in higher surface loadings of physisorbed protein. The ability to load higher amounts of protein onto particles with this surface makes them ideal starting materials for bioconjugation applications such as lateral flow where a robust and dense antibody layer can increase assay sensitivity.
- Highly displaceable surface groups for performing ligand exchange with proteins or other ligands. Molecules with thiols or amine will strongly associate with gold or silver surfaces, readily displacing carbonate.
- Carbonate has a minor effect on hydrodynamic diameter with the TEM measured diameter very close to the hydrodynamic diameter as measured with DLS.
- Negatively charged Zeta potential
Representative Source: Potassium carbonate (Sigma Aldrich P5833)
Molecular Weight: K2CO3 (138.2), CO3 (60.0)
Comparison to Alternatives
Displaceable: Carbonate is more displaceable than citrate and tannic acid stabilized particles; closest to “bare” surface of all our particles
- Negatively charged
Toxicity: Very low
Solvent compatibility: Water, low osmolarity buffers
- Lateral Flow
- Color engineering