Hydrogels can be composed of natural or synthetic polymers. They form a three-dimensional (3D) scaffold that can absorb a large quantity of water (>99% by volume). They can mimic the extracellular matrix, having good biocompatible and biodegradable qualities, which enables them to support the growth of cultured cells. Among the various polymers for forming hydrogels, short peptides are an important group. It has been shown that several peptides can undergo gelation and form the 3D structure of a hydrogel, such as peptides that influence the selective differentiation of neural cells, short alternating charged amino acid peptides, and peptide clusters from the nuclear pore complex. Moreover, the addition of the protective group N-fluorenylmethoxycarbonyl (Fmoc) to the short peptides may improve the hydrogel formation process. Naturally self-assembled nanostructures of protein fibrils are associated with neurodegenerative conditions such as Alzheimer's disease, where the fibril structure is made of amyloid-b (Ab) peptides. It has been found that the minimal core recognition motif of Ab peptides is a diphenylalanine element. The chemically synthesized dipeptide NH 2 -Phe-Phe-COOH (FF) can self-assemble into well-ordered peptide nanotubes (PNTs). By using the FF motif connected to an Fmoc moiety (Fmoc-FF), we have shown the formation of a peptidebased hydrogel made from a PNT network. In the work presented here, we have examined the optical properties, optical absorption and photoluminescence (PL), of hydrogels that were self-assembled from Fmoc-FF building blocks. From the optical properties we were able to follow the formation of a quantum confined structure within the hydrogel nanotubes. The most common example of quantum confinement (QC) is a 2D-QC-also called a quantum well (QW)-system of GaAs. This system contains various structures, the most noticeable of which is GaAs/AlGaAs, along with GaAs/InGaAs and InGaN/GaN. These structures have a double heterostructure consisting of a thin layer of GaAs ca. 10 nm thick, whose bandgap is smaller than that of the surrounding AlGaAs bulk.