It is well known that the nanoscale combination of organic compounds with inorganic solids leads to a class of nanostructured materials known as hybrids. Usually, the organic part comes from synthetic compounds, but their substitution by substances from biological species is at the origin of so-called biohybrid materials. This represents a major advance in the field of functional materials, as the incorporation of biological entities, such as cell fragments or even integral microspecies, confers properties on inorganic solids that far surpass systems using exclusively synthetic compounds.
Examples of biohybrid systems include inorganic nanoparticles modified with fragments of plant cell species performing artificial photosynthesis. Another example is the assembly of enzymes on biocompatible solids for the development of biosensors and biocatalysts, or even the immobilization of living cells in silicate matrices that enable them to survive for long periods of time.
The preparation of biohybrids according to bottom-up methods applied to nanotechnology uses well-defined construction units and follows typical soft chemistry processes, in order to avoid the alteration of entities of biological origin, which are generally fragile and sensitive. Examples of systems of particular interest include the immobilization of enzymes in sol-gel matrices, the inclusion of chlorophyll in mesoporous silicas, the encapsulation of living cells in rigid or flexible matrices, and the intercalation of biopolymers in two-dimensionally organized solids.
