Metal-free, strain-promoted alkyne–azide cycloaddition (SPAAC) is employed as a versatile technology for the modification of glass with biomolecules. Patterning is executed by stamping of a fluorogenic azidocoumarin or a cyclooctyne to the glass surface, to obtain a unique anchor point for subsequent functionalization by SPAAC. The azidocoumarin at the same time enables straightforward fluorescent read-out of surface reactions. A strong increase in fluorescence is indeed observed upon metal-free reaction with two readily available cyclooctynes, BCN or DIBAC. In addition, functionalized BCN derivatives are employed for glass surface patterning with biotin or even a 27 kDa protein (green fluorescent protein), upon simple incubation.
Wijdeven, M. A., Nicosia, C., Borrmann, A., Huskens, J., & van Delft, F. L. (2014). Biomolecular patterning of glass surfaces via strain-promoted cycloaddition of azides and cyclooctynes. RSC advances, 4(21), 10549-10552. https://doi.org/10.1039/C3RA46121A