Selective patterning and immobilization of biomolecules within precisely-defined micro-reservoirs

Herein, we present the fabrication of well-defined micro-reservoirs and a simple strategy to immobilize biomolecules selectively inside the reservoirs. The micro-reservoirs are fabricated using a photocurable prepolymer, which enables the formation of concrete structures with high-fidelity, so that the reservoirs are spatially-segregated from each other by rigid physical barriers. For the directed binding of the protein, two steps are involved. First, poly(ethylene glycol) (PEG) is contact-printed on those areas where the protein binding is not desired, and next, protein binding is promoted where desired via carbodiimide chemistry. Fluorescein-tagged albumin is successfully immobilized inside the micro-reservoirs and microchannel arrays with high sensitivity, regardless of the sizes of the reservoirs and channels. The proposed system can be used for constructing multi-functional biosensors by immobilizing individual bioorganisms specifically in each micro-reservoir or microchannel.