Multivalent Binding of Small Guest Molecules and Proteins to Molecular Printboards inside Microchannels

β‐Cyclodextrin (β‐CD) monolayers have been immobilized in microchannels. The host–guest interactions on the β‐CD monolayers inside the channels were comparable to the interactions on β‐CD monolayers on planar surfaces, and a divalent fluorescent guest attached with a comparable binding strength. Proteins were attached to these monolayers inside microchannels in a selective manner by employing a strategy that uses streptavidin and orthogonal linker molecules. The design of the chip, which involved a large channel that splits into four smaller channels, allowed the channels to be addressed separately and led to the selective immobilization of antibodies. Experiments with labeled antibodies showed the selective immobilization of these antibodies in the separate channels. Down‐sized channels: The immobilization of β‐CD monolayers inside microchannels is described. These microchips are designed such that they can be used for the selective immobilization of proteins in different channels. One example is the alternating fashion in which two fluorescently labeled antibodies are immobilized in the chip (see figure).