Biogenic porous silica and silicon sourced from Mexican Giant Horsetail (Equisetum myriochaetum) and their application as supports for enzyme immobilization

Abstract

Porous silica-based materials are attractive for biomedical applications due to their biocompatibility and biodegradable character. In addition, inorganic supports such as porous silicon are being developed due to integrated circuit chip compatibility and tunable properties leading to a wide range of multidisciplinary applications. In this contribution, biosilica extracted from a rarely studied plant material (Equisetum Myriochaetum), its conversion to silicon and the potential for both materials to be used as supports for enzyme immobilization are investigated. E. myriochaetum was subject to conventional acid digestion to extract biogenic silica with a% yield remarkably higher (up to 3 times) than for other Equisetum sp. (i.e. E. Arvense). The surface area of the isolated silica was ∼400 m/g, suitable for biotechnological applications. Biogenic silicon was obtained by magnesiothermic reduction. The materials were characterized by SEM-EDX, XRD, FT-IR, ICP-OES, TGA and BET analysis and did not contain significant levels of class 1 heavy elements (such as Pb, Cd, Hg and As). Two commercial peroxidases, horseradish peroxidase (HRP) and Coprinus cinereus peroxidase (CiP) were immobilized onto the biogenic materials using three different functionalization routes: (A) carbodiimide, (B) amine + glutaraldehyde and (C) amine + carbodiimide. Although both biogenic silica and porous silicon could be used as supports differences in behaviour were observed for the two enzymes. For HRP, loading onto biogenic silica via the glutaraldehyde immobilization technique (route B) was most effective. The loading of CiP showed a much higher peroxidase activity onto porous silicon than silica functionalized by the carbodiimide method (route A). From the properties of the extracted materials obtained from Equisetum Myriochaetum and the immobilization results observed, these materials appear to be promising for industrial and biomedical applications.

Biogenic amorphous silica as main driver for plant available water in soils

“…1). The explanation of the equal WHC is that plant ASi and Aerosil 300 have similar surface area (~400 m 2 g −1 for plant bASi and ~300 m 2 g −1 for Aerosil 300) and porosity (0.6-0.9 cm 3 g −1 for plant bASi and 0.56 cm 3 g −1 for Aerosil 300) 25,26 . The high surface area increases the adsorption of water films on the particle surfaces.…”

Nanosilicon-Based Composites for (Bio)sensing Applications: Current Status, Advantages, and Perspectives

“…As mentioned below, biofunctionalization plays a very important role in bioselective layer evolution and allows for the binding of organic molecules to a non-organic nano-Si surface without unspecific interaction. Currently, a number of biofunctionalization protocols have been proposed: silanization [3,19,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67], aminosilanization [68,69,70], direct immobilization [16,22,71,72], enzyme [18] or peptide [73] treatment, phospholipid bilayers formation [74], hydrosilylation treated by N-Hydroxysuccinimide and 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (NHS/EDC) [75,76,77] or resazurin [78], and polymer synthesis [79]. However, the most common technique is silanization, due to the possibility of controlling the thickness of the(3-Aminopropyl)triethoxysilane (APTES) layer as well as using different cross-linking agents (glutaraldehyde, NHS/EDS) [18,80].…”

Purification and immobilization of engineered glucose dehydrogenase: a new approach to producing gluconic acid from breadwaste

“…The successful development of an immobilized enzyme process depends on the properties of the enzyme, the specific immobilization process and the properties of the support, including its morphology, composition, particle size, pore structure, specific surface area, surface functional groups and rigidity [23,24]. Due to their robust surface chemistry and tunable morphology, porous silica supports have been extensively studied for enzyme immobilization [25,26]. Various immobilization methods, such as entrapment, encapsulation, self-immobilization, covalent bonding together with techniques to optimize the function of the enzyme once it has been immobilized have been described previously [27][28][29].…”