Recent progress in nanomaterial-enhanced fluorescence polarization/anisotropy sensors

The final publication is available at Elsevier via https://doi.org/10.1016/j.cclet.2019.06.005. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/As a promising signaling transduction approach, fluorescence polarization (FP)/fluorescence anisotropy (FA), provides a powerful quantitative tool for the rotational motion of fluorescently labeled molecules in chemical or biological homogeneous systems. Unlike fluorescence intensity, FP/FA is almost independent the concentration or quantum of fluorophores, but they are highly dependent on the size or molecular weight of the molecules or materials attached to fluorophores. Recently, significant progress in FP/FA was made, due to the introduction of some nanomaterials as FP/FA enhancers. The detection sensitivity is thus greatly improved by using nanomaterials as FP/FA enhancers, and nanomaterial-based FP/FA is currently used successfully in immunoassay, and analysis of protein, nucleic acid, small molecule and metal ion. Nanomaterial-based FP/FA provides a new kind of strategy to design fluorescent sensors and establishes innovative analytical methods. In this review, we summarize the scientific publications in the field of FP/FA sensor in recent five years, and first introduce the recent progress of FP/FA sensor based on nanomaterial. Subsequently, the various analytical applications of FP/FA based on nanomaterial are discussed. Finally, we provide perspectives on the current challenges and future prospects in this promising field.The authors gratefully acknowledge the financial support provided by the National Natural Science Foundation of China (No. 21822407, 21405163) and the top priority program of “One-Three-Five” Strategic Planning of Lanzhou Institute of Chemical Physics, CAS

Synthesis strategies of covalent organic frameworks: An overview from nonconventional heating methods and reaction media

Covalent organic frameworks (COFs), as an emerging class of porous crystalline materials constructed by covalent links between the building monomers, have gained tremendous attention. Over the past 15 years, COFs have made rapid progress and substantial development in the chemistry and materials fields. However, the synthesis of COFs has been dominated by solvothermal methods for a long time and it usually involves high temperature, high pressure and toxic organic solvents, which created many challenges for environmental considerations. Recently, the exploration of new approaches for facile fabrication of COFs has aroused extensive interest. Hence, in this review, we comprehensively describe the synthetic strategies of COFs from the aspects of nonconventional heating methods and reaction media. In addition, the advantages, limitations and properties of the preparation methods are compared. Finally, we outline the main challenges and development prospects of the synthesis of COFs in the future and propose some possible solutions

Effective Removal of Sulfonamides Using Recyclable MXene-Decorated Bismuth Ferrite Nanocomposites Prepared via Hydrothermal Method

Developing a simple and efficient method for removing organic micropollutants from aqueous systems is crucial. The present study describes the preparation and application, for the first time, of novel MXene-decorated bismuth ferrite nanocomposites (BiFeO3/MXene) for the removal of six sulfonamides including sulfadiazine (SDZ), sulfathiazole (STZ), sulfamerazine (SMZ), sulfamethazine (SMTZ), sulfamethoxazole (SMXZ) and sulfisoxazole (SXZ). The properties of BiFeO3/MXene are enhanced by the presence of BiFeO3 nanoparticles, which provide a large surface area to facilitate the removal of sulfonamides. More importantly, BiFeO3/MXene composites demonstrated remarkable sulfonamide adsorption capabilities compared to pristine MXene, which is due to the synergistic effect between BiFeO3 and MXene. The kinetics and isotherm models of sulfonamide adsorption on BiFeO3/MXene are consistent with a pseudo-second-order kinetics and Langmuir model. BiFeO3/MXene had appreciable reusability after five adsorption–desorption cycles. Furthermore, BiFeO3/MXene is stable and retains its original properties upon desorption. The present work provides an effective method for eliminating sulfonamides from water by exploiting the excellent texture properties of BiFeO3/MXene

Deep eutectic solvent-driven self-assembly of metal mercaptide complexes with enzyme-mimicking activities for detection of uric acid through one-step cascade catalytic reaction

This work presents a generic strategy to create a series of metal mercaptides complexes via coordination self-assembly between transition metals (Mn, Cu, Co, Fe, and Ni) and cysteine (Cys) by forming the sulfur-metal bridges. This strategy involves dissolving metal chlorides and Cys into deep eutectic solvents (DES), followed by the precipitation of metal mercaptides complexes (such as Cys-Mn) by adding water as an antisolvent, where DES serves as the solvent, shape directing, and capping agent, thereby preventing the formation of other metal impurities. Interestingly, the prepared complexes possess both laccase and peroxidase-like properties, allowing the design of a technique for the detection of L-3,4-dihydroxyphenylalanine (l-DOPA) and uric acid, respectively. The prepared Cys-Mn can linearly oxidize l-DOPA with its concentrations from 0.1 to 130 μM and the detection limit was calculated to be 75.5 nM. Additionally, the Cys-Mn can mimic the activity of peroxidase towards oxidization of o-phenylenediamine at neutral pH, allowing single-step and one-pot cascade reactions for visual and fluorometric measurements of uric acid (UA) that could work in the range of 0.2–500 μM UA with a detection limit of 0.06 μM and 0.054 μΜ, respectively. The assay was successful in detecting UA in serum and urine samples with relative standard deviation (RSD) ranging from 7.3% to 10.2% and 3.0%–8.5% respectively, suggesting that it may prove useful in medical diagnostic testing

Composite materials based on covalent organic frameworks for multiple advanced applications

Abstract Covalent organic frameworks (COFs) stand for a class of emerging crystalline porous organic materials, which are ingeniously constructed with organic units through strong covalent bonds. Their excellent design capabilities, and uniform and tunable pore structure make them potential materials for various applications. With the continuous development of synthesis technique and nanoscience, COFs have been successfully combined with a variety of functional materials to form COFs‐based composites with superior performance than individual components. This paper offers an overview of the development of different types of COFs‐based composites reported so far, with particular focus on the applications of COFs‐based composites. Moreover, the challenges and future development prospects of COFs‐based composites are presented. We anticipate that the review will provide some inspiration for the further development of COFs‐based composites

Synthesis and characterization of poly(ionic liquid)-grafted silica hybrid materials through surface radical chain-transfer polymerization and aqueous anion-exchange

Poly(ionic liquid)-grafted silica materials were firstly synthesized by polymerization of 1-vinyl-3-butylimidazolium bromide as a new ionic liquid monomer on mercaptopropylated silica by surface radical chain-transfer polymerization. The bromide counterion was exchanged with three other inorganic anions including tetrafluoroborate, hexafluorophosphate, and trifuoromethanesulfonate through simple aqueous anion-exchange reaction. The obtained poly(ionic liquid)-grafted silica materials were characterized by elemental analysis, infrared spectra, thermogravimetric analysis, and X-ray fluorescence. The wettabilities of the materials with different counterions were verified by static water contact angle measurement. This kind of new materials may have some potential in applied fields such as used as a catalyst, an extractant, a chromatographic stationary phase, etc