Chemical functionalization of a photopolymer resin to enable protein immobilization in 3D-printed microfluidic devices

Commercial photopolymer resins used in additive manufacturing are typically designed to be chemically inert, ensuring print fidelity and long-term stability. However, the ability to chemically functionalize printed surfaces would significantly expand the integration of commercial 3D printing with bioanalytical and lab-on-a-chip systems. Here, we introduce a materials-design strategy in which chemical functionality is incorporated directly into the resin formulation. Addition of a copolymerizable acrylamide monomer produces an activation-ready photopolymer resin with surface-accessible functionality suitable for post-print modification, thereby reducing dependence on geometry-sensitive surface-treatment methods. The modified resin retains low autofluorescence and micron-scale printing resolution, maintaining compatibility with fluorescence-based microfluidic assays. The functionalized surface enables glutaraldehyde-mediated immobilization of model proteins, including bovine haemoglobin and bovine serum albumin. Successful protein immobilization was verified by protein staining and wettability measurements, while selective recognition by fluorescent molecularly imprinted nanoparticles revealed highly specific binding under static and flow conditions, with dissociation constants (K d ) of 2.57 and 53.0 nM for target binding. By incorporating modification-ready functionality into a commercial photopolymer resin while preserving its printing and optical properties, this work provides a practical strategy for the rapid fabrication of protein-functionalized 3D-printed microfluidic devices.