Supported Supramolecular Hydrogel Nanoarchitectonics for Tunable Biocatalytic Flow Activity

Abstract Enzymatically‐active polyelectrolyte multilayers containing n layers of phosphatase (AP _n ‐PEM) induce the formation of supported biocatalytic supramolecular hydrogels when brought in contact with the precursor tripeptide Fmoc‐FF p Y (Fmoc = N‐fluorenylmethyloxycarbonyl; F = Phenylalanine; Y = Tyrosine; p = phosphate group). AP _n ‐PEM triggers the spatially‐localized hydrogelation reaching 2, 17 and 350 µm of thickness for n = 1, 2 and 3, respectively. As observed by cryo scanning electron microscopy, a dense nanofibrous network underpinning the hydrogel shows parallelly orientated Fmoc‐FFY peptide‐based fibrils, perpendicular to the substrate. For the gel generated by the AP ₃ ‐PEM, fluorescence confocal microscopy images show that during the peptide self‐assembly, some enzymes are distributed in the hydrogel, preferentially located in few dozens of micrometers above the substrate. In addition, a self‐assembly growth rate of 5 µm min ⁻¹ is determined when the hydrogelation starts. Through transmission electron microscopy immuno‐labelling experiments on self‐assemblies generated in solution, we observe that AP are decorating the Fmoc‐FFY nanofibers. It is observed both a long‐term stability and a higher biocatalytic activity of the so AP‐encapsulated hydrogel compared to the bare AP _n ‐PEM. This bioactivity can be tuned by the number n in batch and under continuous flow conditions. To illustrate the versatility of this enzyme‐supported strategy, multi‐catalytic transformations in continuous flow conditions have been successfully carried out using supported supramolecular hydrogel.