Enzyme‐Based Bioinorganic Materials

Abstract

Trends in research materials currently focus on innovation in the field of intelligent or smart materials [1]. Smart materials are materials that display functionalities able to detect a change in the near environment, answer to a stimulus, modify a property, store, transfer or convert a signal, in a sense behave like living cells. The design of smart materials focuses on the concept of biomimetic materials [2][3][4] in order to reproduce specific and selective properties not deliverable by standard chemical or physical processes. Hence, there has been much effort concentrated on the development of enzyme-based biohybrid materials. Enzyme-based biohybrid materials are under much investigation for the operation of physical or chemical functions. Enzymes display active and selective properties such as molecular recognition, complexation or carrier functions, and a wide range of catalytic reactions (hydrolysis, condensation, redox reaction, isomerization, reaction transfer). Enzymes are thus very attractive as an alternative to traditional catalysts when chemical routes are difficult to apply. Enzymes are able to catalyze regio-and stereo-selective reactions with rate accelerations up to 10-17 fold [17]. They are interesting materials for realization of sensing devices, recognition systems and nanoreactors with many potential industrial developments in biocatalysis [4] for the food industry or effluent treatment [5,6], in biomedical domains for medical implants or enzyme delivery [7], in bioanalysis and affinity chromatography [8,9], and in biosensor technology [10][11][12].Engineering the development of biohybrid enzyme-based materials requires solution of the limitations of the use of enzymes due to their intrinsic fragility against the various environmental stresses and their narrow range of working conditions (e.g. short pH and temperature range). Embedding enzymes in protective matrices in order to solve these problems has been envisaged for many years [13,14]. Immobilization of enzymes in solid supports is seen as a strategy to preserve the active site, to improve the performance of the enzyme, that is, its activity, reaction rate and long-term stability, and to allow enzyme reuse. Physical and chemical properties of the solid supports such as particle size, surface area, pore diameter, mechanical j443 Bio-inorganic Hybrid Nanomaterials. Edited

Zein-layered hydroxide biohybrids: strategies of synthesis and characterization

“…LDHs (Figure 1a), also known as hydrotalcite-like compounds or anionic clays, are widely used as catalysts or catalyst precursors, adsorbents, components in modified electrodes, as inorganic host matrices for drug or herbicide release in medical and environmental applications, or as nanofillers of polymers [13,[15][16][17][18][19][20][21][22][23][24][25][26]. LDHs can be prepared easily following several synthetic approaches, such as direct anion-exchange and coprecipitation or "co-organized assembly," commonly used in the preparation of LDH-based biohybrid materials [27]. In this sense, LDHs such as those based on MnAl, NiAl, and ZnCr have been used as hosts of low molecular weight species such as phenylalanine (Phe) amino acid, which was intercalated by the co-precipitation method [28].…”