Abstract: Disclosed herein are formulations, substrates, and arrays. In certain embodiments, substrates and arrays comprise a porous layer for synthesis and attachment of polymers or biomolecules. Also disclosed herein are methods for manufacturing and using the formulations, substrates, and arrays, including porous arrays. Also disclosed herein are formulations and methods for one-step coupling, e.g., for synthesis of peptides in an N->C orientation. In some embodiments, disclosed herein are formulations and methods for high efficiency coupling of biomolecules to a substrate.