There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes

With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce e...

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Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

Due to the significance of hydrogen peroxide (H(2)O(2)) in biological systems and its practical applications, the development of efficient electrochemical H(2)O(2) sensors holds a special attraction for researchers Various materials such as Prussian blue (PB), heme proteins, carbon nanotubes (CNTs) and transition metals have been applied to the construction of H(2)O(2) sensors In this article, the electrocatalytic H(2)O(2) determinations are mainly focused on because they can provide a superior sensing performance over non-electrocatalytic ones The synergetic effect between nanotechnology and electrochemical H(2)O(2) determination is also highlighted in various aspects In addition, some recent progress for in vivo H(2)O(2) measurements is also presented Finally, the future prospects for more efficient H(2)O(2) sensing are discussed

Recent advances in electrochemical sensing for hydrogen peroxide: a review

Bacteria cellulose (BC) nanofibers are used as robust biotemplates for the facile fabrication of novel gold nanoparticle (NP)-bacteria cellulose nanofiber (Au-BC) nanocomposites via a one-step method. The BC nanofibers are uniformly coated with Au NPs in aqueous suspension using poly(ethyleneimine) (PEI) as the reducing and linking agent. With the addition of different halides, Au-BC nanocomposites with different Au shell thicknesses are formed, and a possible formation mechanism is proposed by taking into account the special role played by PEI. A novel H 2 O 2 biosensor is constructed using the obtained Au-BC nanocomposites as excellent support for horseradish peroxidase (HRP) immobilization, which allows the detection of H 2 O 2 with a detection limit lower than 1 μM. The Au-BC nanocomposites could be further used for the immobilization of many other enzymes, and thus, may find potential applications in bioelectroanalysis and bioelectrocatalysis.

Biotemplated Synthesis of Gold Nanoparticle–Bacteria Cellulose Nanofiber Nanocomposites and Their Application in Biosensing

A facilely synthesized amino-functionalized metal–organic framework for highly specific and efficient enrichment of glycopeptides

Amperometric hydrogen peroxide biosensor based on the immobilization of heme proteins on gold nanoparticles-bacteria cellulose nanofibers nanocomposite.

Synthesis of orientedly bioconjugated core/shell Fe3O4@Au magnetic nanoparticles for cell separation.

Herein, G-quadruplex sequence was found to significantly decrease the diffusion current of methylene blue (MB) in homogeneous solution for the first time. Electrochemical methods combined with circular dichroism spectroscopy and UV–vis spectroscopy were utilized to systematically explore the interaction between MB and an artificial G-quadruplex sequence, EAD2. The interaction of MB and EAD2 (the binding constant, K ≈ 1.3 × 106 M–1) was stronger than that of MB and double-stranded DNA (dsDNA) (K ≈ 2.2 × 105 M–1), and the binding stoichiometry (n) of EAD2/MB complex was calculated to be 1.0 according to the electrochemical titration curve combined with Scatchard analysis. MB was proved to stabilize the G-quadruplex structure of EAD2 and showed a competitive binding to G-quadruplex in the presence of hemin. EAD2 might mainly interact with MB, a positive ligand of G-quadruplex, through the end-stacking with π-system of the guanine quartet, which was quite different from the binding mechanism of dsDNA with MB ...

Ying-Lin Zhou

Papers

Biotemplated Synthesis of Gold Nanoparticle–Bacteria Cellulose Nanofiber Nanocomposites and Their Application in Biosensing

A facilely synthesized amino-functionalized metal–organic framework for highly specific and efficient enrichment of glycopeptides

Amperometric hydrogen peroxide biosensor based on the immobilization of heme proteins on gold nanoparticles-bacteria cellulose nanofibers nanocomposite.

Synthesis of orientedly bioconjugated core/shell Fe3O4@Au magnetic nanoparticles for cell separation.

Methylene blue as a G-quadruplex binding probe for label-free homogeneous electrochemical biosensing.