Editing Conjugated system (section)

===Chromophores===
Conjugated systems form the basis of [[chromophore]]s, which are light-absorbing parts of a molecule that can cause a compound to be colored. Such chromophores are often present in various organic compounds and sometimes present in [[polymer]]s that are colored or glow in the dark. Chromophores often consist of a series of conjugated bonds and/or ring systems, commonly aromatic, which can include C–C, C=C, C=O, or N=N bonds.

[[File:Beta-Carotene conjugation.svg|class=skin-invert-image|thumb|center|530 px|Chemical structure of [[beta-carotene]]. The eleven conjugated double bonds that form the [[chromophore]] of the molecule are highlighted in red.]]

Conjugated chromophores are found in many [[organic compound]]s including [[azo dyes]] (also [[Food coloring|artificial food additives]]), compounds in fruits and vegetables ([[lycopene]] and [[anthocyanidin]]s), [[photoreceptor cell|photoreceptor]]s of the eye, and some pharmaceutical compounds such as the following:

[[File:Amphotericin B new.svg|class=skin-invert-image|thumb|500px|center|This [[polyene antimycotic]] called  [[Amphotericin B]] has a conjugated system with seven double bonds acting as a chromophore that absorbs strongly in the [[ultraviolet–visible spectroscopy|ultraviolet–visible]] spectrum, giving it a yellow color]]

Conjugated polymer [[nanoparticle]]s (PDots) are assembled from hydrophobic fluorescent conjugated polymers, along with [[amphiphilic]] polymers to provide water solubility. Pdots are important labels for [[Single-molecule experiment|single-molecule]] [[fluorescence microscopy]], based on high brightness, lack of [[Fluorescence intermittency in colloidal nanocrystals|blinking]] or [[fluorophore|dark fraction]], and slow [[photobleaching]].<ref>{{Cite journal|vauthors = Wu C, Hansen SJ, Hou Q, Yu J, Zeigler M, Jin Y, Burnham DR, McNeill JD, Olson JM, Chiu DT| title = Design of highly emissive polymer dot bioconjugates for in vivo tumor targeting  |journal=Angewandte Chemie | volume = 50 | issue = 15 | pages = 3430–4 | date = 2011 | pmid =  21381164 | pmc = 3095208 |doi = 10.1002/anie.201007461 |doi-access=free }}</ref><ref>{{cite journal |vauthors=Koner AL, Krndija D, Hou Q, Sherratt DJ, Howarth M |year=2013|title= Hydroxy-terminated conjugated polymer nanoparticles have near-unity bright fraction and reveal cholesterol-dependence of IGF1R nanodomains |journal=ACS Nano |pmid=23330847 |doi=10.1021/nn3042122 |volume=7 |pages=1137–1144 |issue=2 |pmc=3584654|doi-access=free }}</ref>