Enzyme nanoparticles

Kim J, Grate JW (2003). Single-enzyme nanoparticles armored by a nanometer-scale organic/ inorganic network. Nano Lett. 3 1219-1222. 

This area of research is also denoted as nanobiocatalysis. A range of possible ways to stabilize enzymes in these nanostructures has been developed. Figure 2.23 reports, as an example, a cartoon of the encapsulation of an enzyme inside a silica shell (single enzyme nanoparticles, SENs) [185], and its support over (i) conductive materials (carbon or oxide semiconductor nanofibers or nanotubes) to realize biosensors or electrodes for biofuel cells and (ii) mesoporous materials (e.g., SBA-15, or MCM-41) to develop robust biocatalysts for bioremediation or chemical applications. 

Figure 2.23 Encapsulation of an enzyme inside a silica shell (single enzyme nanoparticles, SENs), and the support of these SENs over conductive supports or silica mesoporous material. Source adapted from Kim et al. [178].

Figure 3-10. The assembly of an Au-nanoparticle (1.4 nm) electrically contacted glucose oxidase electrode by (a) the primary reconstitution of apo-GOx on the FAD-functionalized Au-nanoparticle, and the immobilization of the enzyme-nanoparticle hybrid on an electrode surface (b) the primary immobilization of the FAD-modified Au-nanoparticle on tire electrode surface and the surface reconstitution of apo-GOx on the functionalized electrode. Reproduced with permission from ref. 41. Copyright 2003, AAAS.

Keighron, J.D., Keating, C.D., 2010. Enzyme nanoparticles bioconjugates with two sequential enzymes stoichiometry and activity of malate dehydrogenase and citrate synthase on Au nanoparticles. Langmuir 26 (24), 18992—19000. 

Effect of pH. If ionic strength changes cannot render PAH/PSS capsules permeable to larger species (e.g., macromolecules, enzymes, nanoparticles), then manipulation of pH or solvent polarity can be used. The point about the (PAH/PSS) system is that PSS is a strong polyelectrolyte and remains fully ionized, whereas PAH is a weak polyelectrolyte and so its dissociation is dependent on pH. 

A recent advance in nanobiocatalysis is the development of single enzyme nanoparticles (SEN) based on the concept of self-assembly. The concept of SEN is based on the development of nanometric porous organic/inorganic shell covering the enzyme surface forming a shield (Figure 10.3). 

Figure 103 Scheme of single enzyme nanoparticle synthesis. 

Heged 1, Nagy E. Improvement of chymotrypsin enzyme stability as single enzyme nanoparticles. Chem Eng Sci 2009 64 1053-60. 

Optical aptasensors include label-based aptamers (using fluorophore, luminophore, enzyme, nanoparticles) or label-free detection systems (e.g. surface plasmon resonance). Aptamers have also been widely used as biorecognition elements in... 

Enzyme Nanoparticles used Kinetic parameters Appiication(s) Ref. 

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