"Clicking" Surfaces with Sunlight

Engineering the chemistry and topography of surfaces affords technological advancements for a variety of applications ranging from biosensors to microelectronics. In this work, graduate student Ryan Hensarling and coworkers demonstrated thiol-yne click chemistry as a modular platform for rapid fabrication of highly functional, patterned, and multicomponent surfaces.  The radical-mediated reaction of a thiol with an alkyne generates a dithioether adduct in near quantitative yields under ambient air, temperature, and humidity conditions.  Here, brush surfaces expressing a three-dimensional configuration of “yne” functionalities were modified with high efficiency and short reaction times (several minutes) using a library of commercially available thiols, including functional thiols that demonstrate applicability for pH responsive surfaces and for bioconjugation.  Patterned and multicomponent brush surfaces were obtained using a simple UV photopatterning technique and sequential thiol-yne reactions.  Since thiyl radicals can be generated using visible light, surfaces were modified with thiol-yne click reactions outdoors using sunlight as the radiation source.  These results suggest the possibility of large scale surface modifications using renewable energy resources. 

Further reading: Hensarling, R.; Doughty, V.; Chan, J.; Patton, D.
 "Clicking Polymer Brushes with Thiol-Yne Chemistry: Inside and Out"
J. Am. Chem. Soc. 2009, 131, 14673-14675. Link