Hi Melika Gorgani,

avoiding aggregation of gold nanoparticles during antigen conjugation can be a challenging task, but there are several strategies you can try to improve the stability of the conjugates and prevent aggregation. Try using stabilizing agents such as polyethylene glycol (PEG) or Tween-20 during the conjugation process. These agents can help prevent particle aggregation and provide steric stabilization to the nanoparticles. Another possibility that comes to mind is maneuvering the parameters of nanoparticle formation. For example ensure that the pH adjustment of the target antigen and the addition of the antigen to the gold solution are performed carefully to minimize any sudden changes in pH that could trigger aggregation. Maybe, try the Quality by Design approach when developing your next experiments following:

Article Quality by Design (QbD) based process optimisation to develo...

Good luck

Hi Melika Gorgani,

Conjugation is the process by which one bacterium transfers genetic material to another through direct contact. Therefore, many citrate-effects in stabilization of aggregated of gold nanoparticles that work as a crucial role such as add a surfactant (salt), temperature, pH of the solution, and etc. which fabricate to surface charge of the gold nanoparticle becomes neutral, causing nanoparticles to aggregate.

Having tween 20 helps, you still need to add enough antigen to have a stable system.