Solids Go Bio: Inorganic Nanoparticles as Enzyme Mimics

Abstract

A longstanding goal of biomimetic chemistry is the design and synthesis of functional enzyme mimics. The past three decades have seen a wide variety of materials, including metal complexes, polymers and other biomolecules, that mimic the structures and functions of naturally occurring enzymes. Among these, inorganic nanoparticles offer huge potential, because they are more stable than their natural counterparts, while having large surface areas and sizes comparable to those [a] of natural enzymes. Therefore, a considerable number of "artificial enzymes" derived from inorganic nanomaterials have been reported. This microreview highlights the recent progress in the field of enzymatically active inorganic nanomaterials, including mimics of peroxidases, haloperoxidases, superoxide dismutases and sulfite oxidases, along with selected biotechnological applications and their future prospects.

A Review on Iron Oxide‐Based Nanoarchitectures for Biomedical, Energy Storage, and Environmental Applications

“…Colorimetric Biosensors/Nanozymes : The enzyme‐mimicking ability of iron oxide NPs was first discovered in 2007, in which ferromagnetic Fe 3 O 4 NPs were shown to exhibit intrinsic peroxidase‐like activity with catalytic behavior identical to horseradish peroxidase (HRP) . Since then, many other nanomaterials, including metals, metal oxides, carbons, and metal‐modified carbons have been demonstrated to show enzyme‐like activities with catalytic behaviors resembling peroxidase, catalase, glucose oxidase, sulfite oxidase, haloperoxidase, superoxide dismutase, and NADH peroxidase . Thus, the term “nanozymes” has been coined to refer to nanomaterials with enzyme‐mimicking abilities and to distinguish them from externally immobilized enzymes …”

Diagnosis of rubella virus using antigen-conjugated Au@Pt nanorods as nanozyme probe

“…[13][14][15][16] Nanozymes comprise many types of materials, iron oxide, vanadium oxide, cerium oxide, manganese oxide, gold, platinum, palladium, gold-silver alloys, carbon nanotubes, graphene, metal chalcogenides, and other [17][18][19][20][21][22][23][24][25][26] Compared with natural enzymes, nanozymes are advantageous in several aspects, such as low cost, ease of mass production, robustness to harsh environments, high stability, long-term storage, large surface area for further modification and bioconjugation and so on. [27][28][29][30][31][32] Previously, we found Au-Pt core/shell nanorods (Au@Pt NRs) have intrinsic multiple enzyme mimetic capability, for example, oxidase, peroxidase, and catalase mimetic activity. [33][34][35][36][37] The as-synthesized Au@Pt NRs are able to catalyze color reactions in immunoassay and, therefore, can be used to replace the enzymes in conventional ELISA.…”

New colorimetric method to determine catalase mimic activity

“…The standard curve contained the following concentration of KMnO 4 (0, 1, 2, 3, 4 and 5) ×10 -5 M, was prepared to calculate the different color concentrations absorbed by KMnO 4 at the length wave 525 nm (as shown in figure 1). The mimic activity, was measured using the reaction with the solution of MnO 2 nanoparticle (2 mM), and solution of H 2 O 2 (750 μM), as shown in the reaction [10]:…”

“…Goth [8] used other colorimetric methods for CAT by measuring spectrophotometrically the unreacted H 2 O 2 by reacting a compound with the ammonium molybdate. Another method used by Sinha and Hadwan [9,10] which are the hydrogen breakdown of H 2 O 2 measured (spectrophotometrically) by the reaction of dichromate and acetic acid as a reagent to formation complex. The titration method considered as a method for measurement of catalase activity, this method used when precipitation or pigmentation was formed, these do not allow in the UVspectrophotometric method [5].…”