Editing Colloidal gold (section)

===Martin method===
This simple method, discovered by Martin and Eah in 2010,<ref>{{cite journal | vauthors = Martin MN, Basham JI, Chando P, Eah SK | title = Charged gold nanoparticles in non-polar solvents: 10-min synthesis and 2D self-assembly | journal = Langmuir | volume = 26 | issue = 10 | pages = 7410–7 | date = May 2010 | pmid = 20392108 | doi = 10.1021/la100591h }}  A 3-min demonstration video for the Martin synthesis method is available at [https://www.youtube.com/watch?v=nqkwM9o1s-w YouTube]</ref> generates nearly monodisperse "naked" gold nanoparticles in water. Precisely controlling the reduction stoichiometry by adjusting the ratio of NaBH<sub>4</sub>-NaOH ions to HAuCl<sub>4</sub>-HCl ions within the "sweet zone," along with heating, enables reproducible diameter tuning between 3–6&nbsp;nm. The aqueous particles are colloidally stable due to their high charge from the excess ions in solution. These particles can be coated with various hydrophilic functionalities, or mixed with hydrophobic ligands for applications in non-polar solvents. In non-polar solvents the nanoparticles remain highly charged, and self-assemble on liquid droplets to form 2D monolayer films of monodisperse nanoparticles.