Protecting the environment and saving resources are two of the society\u2019s challenges of the 21th century. Therefore interesting insights coming also from nature. As many bacteria and archaea live in extreme habitats, they developed early in evolution so called surface layers (S-layers), which function as intelligent interface between cells and their environment. One function of such S-layers is the binding of toxic metals and metalloids and thusly the protection of the cells from being damaged by these elements and their compounds. This makes, together with their self-assembling properties, S-layer very interesting building blocks for the construction of new bioinspired nanomaterials for different technical applications. Currently under development are materials for the selective metal-binding for the removal of toxic metals and metalloids or the recovery of precious metals, highly efficient (photo)catalysts for the elimination of organic pollutants or organic synthesis and new biosensors for chemicals or pharmaceuticals.