Fig. 3
From: Copper-free click chemistry for attachment of biomolecules in magnetic tweezers
Stepwise linkage of DNA to the surface with copper-free click chemistry. Bifunctionalized PEG-linkers are attached to an amine-coated surface via their NHS group. The NHS ester on the PEG conjugates to the amine on the surface. Non-reactive PEG linkers (terminated with a CH3-group) are used to passivate the surface. Finally, a DBCO group on DNA clicks with the azide and thus forms a covalent bond between the DNA and the surface