Single 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].

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. 

Metallic nanoparticles and single-walled carbon nanotubes (SWCNTs) exhibit nanoscale dimensions comparable with the dimensions of redox proteins. This enables the construction of NP-enzyme or SWCNT-enzyme hybrids that combine the unique conductivity features of the nanoelements with the biocatalytic redox properties of the enzymes, to yield wired bioelectrocatalyts with large electrode surface areas. Indeed, substantial advances in nanobiotechnology were achieved by the integration of redox enzymes with nanoelements and the use of the hybrid systems in different bioelectronic devices.35... 

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