BSA-templated MnO2 nanoparticles as both peroxidase and oxidase mimics

Abstract

Inorganic nanomaterials that mimic enzymes are fascinating as they potentially have improved properties relative to native enzymes, such as greater resistance to extremes of pH and temperature and lower sensitivity to proteases. Although many artificial enzymes have been investigated, searching for highly-efficient and stable catalysts is still of great interest. In this paper, we first demonstrated that bovine serum albumin (BSA)-stabilized MnO(2) nanoparticles (NPs) exhibited highly peroxidase-, oxidase-, and catalase-like activities. The activities of the BSA-MnO(2) NPs were evaluated using the typical horseradish peroxidase (HRP) substrates o-phenylenediamine (OPD) and 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of either hydrogen peroxide or dissolved oxygen. These small-sized BSA-MnO(2) NPs with good dispersion, solubility and biocompatibility exhibited typical Michaelis-Menten kinetics and high affinity for H(2)O(2), OPD and TMB, indicating that BSA-MnO(2) NPs can be used as satisfactory enzyme mimics. Based on these findings, BSA-MnO(2) NPs were used as colorimetric immunoassay tags for the detection of goat anti-human IgG in place of HRP. The colorimetric immunoassay using BSA-MnO(2) NPs has the advantages of being fast, robust, inexpensive, easily prepared and with no HRP and H(2)O(2) being needed. These water-soluble BSA-MnO(2) NPs may have promising potential applications in biotechnology, bioassays, and biomedicine.

Au@Ag Heterogeneous Nanorods as Nanozyme Interfaces with Peroxidase-Like Activity and Their Application for One-Pot Analysis of Glucose at Nearly Neutral pH

“…65 Taken together, due to the synergistic effect of specific surface property, composition and nano-structure, the catalytic activity of Au@Ag heterogeneous NRs at pH 6.5 differed from that of other similar nanomaterials, such as positively charged PDDA modified Au@Pt core/shell NRs (pH 4.5) or negatively charged PSS modified Au@Pt core/shell NRs (pH 4.5), 46 positively charged CTAB-modified Au@Pt core/shell NRs (pH 4.5), 40 concentration was detected in the neutral condition, which was different from other peroxidase-mimetic materials used in acidic conditions reported so far. [23][24]26 In addition, this performance can also be comparable with our recent results on the detection of H 2 O 2 by using Au@Ag heterogeneous NRs-based electrochemical sensor . 59 Thus, it is beneficial to directly detect the real samples (such as serum and drink) without adjusting the pH value.…”

A sensitive hydrogen peroxide biosensor using ultra-small CuInS2 nanocrystals as peroxidase mimics

“…4C and D, the slopes of the lines are parallel, indicating a ping-pong mechanism [6,34] and implying that the CuInS 2 nanocrystals bind and react with the first substrate and then release the first product before reacting with the second substrate.…”

“…Recently, nanomaterials-based artificial enzyme mimetics with high catalytic properties and a wide range of practical applications are becoming a significant field for different purposes. Various nanomaterials including metallic oxide (Fe 3 O 4 nanoparticles [3], CeO 2 nanoparticles [4], Co 3 O 4 nanoparticles [5], MnO 2 nanoparticles [6], V 2 O 5 nanowires [7], CuO nanoparticles [8]), FeS nanoparticles [9], carbon-based nanomaterials (carbon nanotube [10], helical carbon nanotube [11], graphene [12], graphene oxide [13], carbon nanodots [14]), metallic and bimetallic alloy nanostructures (Au nanoparticles [15], Pt nanoparticles [16], Au and Cu nanoclusters [17,18], Au/Ag nanoparticles [19] Au/Pt nanoparticles [20]), and layered double hydroxide [21] have been applied in the biochemical applications as enzyme mimetics. However, there is much demand to explore the stable, dispersive, and easily prepared nanomaterials with good catalytic properties as peroxidase mimetics in the practical application.…”

Nanozyme applications in biology and medicine: an overview

“…nanosheets, nanospheres, nano-sticks, nano-complexes and nanowires) have also been studied to determine their oxidase and peroxidase and catalase mimicking activity [60]. Liu et al showed that BSA-stabilized Mno þ2 can be used instead of HRP enzyme and in the detection of goat anti-human in immunoassay technic as a colorimetric application [60].…”

“…Experimental studies demonstrated that the H 2 O 2 -activating ability of Fe 3 O 4 MNPs is not so close to the removal of hydrogen superoxide, but it may modify by increasing the H 2 O 2 -activating ability of Fe 3 O 4 MNPs of refractory organic pollutants from wastewaters [60]. H 2 O 2 detection is useful in many fields such as biology, medicine, environmental protection and the food industry [61].…”