Question

Gold nanoparticles research

1. Based on the fact that the citrate anions cover the surface of each nanoparticle, explain what keeps the nanoparticles from sticking together (aggregating) in the original solution. 2. Why does adding the salt solution produce a different result from adding the sugar solution? 3. How could the effect in part C be used to detect the binding of biomolecules, such as DNA or antibodies, that stick to one another or to other molecules? How could these molecules be used to cause aggregation of the nanoparticles?

psdt. Part C is data collected in the second picture

Answer 1

Q. 1 Answer Colloidal gold and silver can be made using sodium cipate to reduce the metal ions and estabilize the nanoparticles Cipate anions attach to the surface of the metal particle, blocking the Coagulating. Gold nanoparticles are about 13 nm. - cipate ions interact with the surface of the nanoparticles to foom a barrieš around the nanoparticle. This is what prevents Hanoperteles sponn Øticking Jogether and clumping into larger profieles By adding Nach the relationship between cipate ion and nanoparticle Dessupted, allowing nang pentiele to clump together. I cipate ý negative on the surface on gold nano particles. Adding citrate to the gold surface gives them some charge and helpos stabilize them in water st s also beneficial as it has a relatively low affinity for the gold surface and can be easily exchanged for something else I