Because of the high catalytic activities and substrate specificity, natural enzymes have been widely used in industrial, medical, and biological fields, etc. Although promising, they often suffer from intrinsic shortcomings such as high cost, low operational stability, and difficulties of recycling. To overcome these shortcomings, researchers have been devoted to the exploration of artificial enzyme mimics for a long time. Since the discovery of ferromagnetic nanoparticles with intrinsic horseradish peroxidase-like activity in 2007, a large amount of studies on nanozymes have been constantly emerging in the next decade. Nanozymes are one kind of nanomaterials with enzymatic catalytic properties. Compared with natural enzymes, nanozymes have the advantages such as low cost, high stability and durability, which have been widely used in industrial, medical, and biological fields. A thorough understanding of the possible catalytic mechanisms will contribute to the development of novel and high-efficient nanozymes, and the rational regulations of the activities of nanozymes are of great significance. In this review, we systematically introduce the classification, catalytic mechanism, activity regulation as well as recent research progress of nanozymes in the field of biosensing, environmental protection, and disease treatments, etc. in the past years. We also propose the current challenges of nanozymes as well as their future research focus. We anticipate this review may be of significance for the field to understand the properties of nanozymes and the development of novel nanomaterials with enzyme mimicking activities.

Nanozymes: Classification, Catalytic Mechanisms, Activity Regulation, and Applications

Detection Ying Zhou,†,‡ Jun Feng Zhang, and Juyoung Yoon*,† †Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea ‡Key Laboratory of Medicinal Chemistry for Natural Resource, School of Chemical Science and Technology, Yunnan University, Kunming, 650091, P. R. China College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650500, P. R. China

Fluorescence and colorimetric chemosensors for fluoride-ion detection.

Molecules containing polarized N−H fragments behave as H-bond donors toward anions and are widely used as receptors for recognition and sensing purposes in aprotic solvents (CHCl3, MeCN, and DMSO). We present examples of receptors containing pyrrole and urea subunits, and we discuss the stability of their H-bond complexes with a variety of anions. It is demonstrated that the stability of the 1:1 complexes is strictly related to the acidic tendencies of the receptor and to the basic properties of the anion. It may happen also that more basic anions induce the deprotonation of the receptor, if equipped with electron-withdrawing substituents. This is typically observed on interaction with fluoride, due to the formation of the very stable [HF2]- self-complex. For urea-based receptors armed with chromogenic substituents, the addition of a large excess of the anion (F-, OH-) may induce the consecutive deprotonation of both N−H fragments, processes signaled by the development of vivid colors.

What anions do to N-H-containing receptors.

Recognition and sensing of fluoride anion.

Artificial Receptors for the Recognition of Phosphorylated Molecules Amanda E. Hargrove, Sonia Nieto, Tianzhi Zhang, Jonathan L. Sessler,* and Eric V. Anslyn* Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165, United States Universidad de Zaragoza, Zaragoza, Spain Henkel Corporation, Rocky Hill, Connecticut 06067 Department of Chemistry, Yonsei University, Seoul, 120-749 Korea

/pdf/artificial-receptors-for-the-recognition-of-phosphorylated-1mwlr6bjuc.pdf

Artificial receptors for the recognition of phosphorylated molecules

Visible colorimetric fluoride ion sensors.

A novel fluoride ion colorimetric chemosensor.

Anion complexation. A ditriphenylphosphonium calix[4]arene derivative as a novel receptor for anions

Fluoride sensor, Color change, Anthraquinone, Urea derivativeAnions play an important role in a wide range of chemicaland biological processes, and considerable attention has beenfocused on the design of host molecules that can recognizeand sense anion species selectively through the naked eye,electrochemical, and optical responses.

http://koreascience.or.kr:80/article/JAKO200602727441737.pdf

Naked Eye Fluoride Ion Chemosensors with Anthraquinone Derivatives

Department of Chemistry and The Institute of Basic Sciences, Chonnam National University, Gwangju 500-757, KoreaReceived March 18, 2003Key Words : Calix[4]arene, Anion receptor, Bridged urea derivativeSelective complexation of anions is more demanding thanthat of cations due to the many reasons such as size, chargedensity, polarizability, solvation energy and pH-dependentacid-base equilibria.

Byung Ju Ryu

Papers

Visible colorimetric fluoride ion sensors.

A novel fluoride ion colorimetric chemosensor.

Anion complexation. A ditriphenylphosphonium calix[4]arene derivative as a novel receptor for anions

Naked Eye Fluoride Ion Chemosensors with Anthraquinone Derivatives

Synthesis and Anion Binding Properties of the Bridged Urea Derivatives of Calix[4]arene