Surface Patterning of Biomolecules Using Click Chemistry and Light-Activated Electrochemistry to Locally Generate Cu(I)

Here we report a light-assisted variant of click chemistry suitable for chemical patterning of semiconducting surfaces. Using a visible light beam to illuminate desired locations of an electrode surface, localized electrogeneration of the Cu(I) click catalyst was achieved. It was demonstrated that surface click reactions were correlated with a user-defined 2D light pattern projected on a silicon photoelectrode. This new process is mask-free and parallel, i. e., separate discrete regions of a semiconducting surface can be simultaneously reacted with a range of functional molecules. The covalent patterning of azido-poly (ethylene glycol) molecules (PEG) over alkyne-functionalized electrodes was employed as a proof-of-principle. By modulating the exposed chemical group of the clicked azido-PEGs, the adhesion of antibodies and cells was further possible with spatial control. The use of structured light, instead of physical masks, drastically reduces patterning time to a couple of hours.