Pillararene-Gold Nanoparticle Composites

Adapted from ref. 28 with permission from The Royal Society of Chemistiy. 

The TEM image of gold nanoparticles stabilized by water-soluble pil-lar[5]arenes at a concentration of 200 pM reveals a spherical shape with an average diameter of 1.88 0.58 nm and the relatively narrow particle size distribution. The well-defined Ctystalline planes can be observed from the high-resolution TEM image. 

Reprinted with permission from ref. 29. Copyright 2013 American Chemical Society. 

The CP[5]A-stabilized gold nanoparticles can be used as optical probes to detect herbicide. Viologen I can stably complex with CP[5]A at a 1 1 molar ratio. Upon addition of different amounts of viologen I, the solution color of CP[5]A-modified AuNPs changes in five minutes. Because the CP[5]A-modi-fied gold nanoparticles have negatively charged surfaces due to the 

---