With the rapid development of current society and economy, as well as the accelerated process of industrialization and urbanization, the complexity and seriousness of environmental pollution issues are becoming increasingly apparent. Beyond traditional pollutants, the appearance of emerging pollutants on a global scale has brought new challenges to environment and public health. China’s “14th Five-Year Plan” and medium and long-term planning put forward “emerging pollutant control”, report of the 20th National Congress of the Communist Party of China also explicitly requested “carry out emerging pollutant control”. In 2022, General Office of the State Council issued “Action Plan for Emerging Pollutant Control”, followed by the Ministry of Ecology and Environment and various provinces, municipalities, and autonomous regions, which released corresponding implementation plans, China has transferred to a new phase of environmental protection that balances the control of both traditional and emerging pollutants. However, management of emerging pollutants is a long-term, dynamic and complex systematic project, which urgently needs to strengthen top-level design as well as scientific and technological support. Conducting systematic research on emerging pollutants not only provides effective scientific guidance for their control and improves the level of environmental quality management, but also assists our country in fulfilling international conventions, enhances the discourse power in global environmental governance, ensures our country environmental security, food security, international trade security, etc., and is of great significance for realizing sustainable development. This review aims to comprehensively explore various aspects of emerging pollutants, including their types and characteristics, production, use and emission, identification and detection, environmental occurrence, migration and transformation, ecotoxicological effects, human exposure, health risks, and management strategies. Furthermore, it looks forward to the future research direction, with a view to providing a scientific basis and decision-making support for control of emerging pollutants in China.

With the proposal of "peak carbon dioxide emissions" and "carbon neutral" strategic objectives, developing clean energy and promoting the development of new energy industry has become the consensus of the whole society. Lithium battery as the candidate for new generation of energy storage equipment due to its remarkable advantages such as high energy density, high power density, long cycle life and environmental friendliness. Its development plays a significant role in alleviating energy crisis, driving the conversion of old kinetic energy into new and achieving the strategic goal of "carbon peaking and carbon neutrality". In order to further improve the energy density of lithium batteries, the most effective strategy is to use high voltage or high specific capacity cathode materials. However, due to the low oxidation stability and narrow electrochemical window of traditional carbonate ester electrolytes, they are prone to oxidative decomposition when the working voltage exceeds 4.2 V, which cannot be cycled stably at high voltages, so it is particularly important to broaden the electrochemical window of electrolytes. This paper mainly discusses the mechanism of organic solvents and additives in high-voltage electrolytes, explores effective methods to broaden the electrochemical window of new electrolytes, summarizes the characteristics of aqueous electrolytes, solid electrolytes, and polymer gel electrolytes, and finally; summarizes and outlooks the future development and prospects of high-voltage electrolytes to provide scientific basis for the design and development of high-voltage electrolytes for lithium batteries.

With the massive global consumption of fossil fuels, the energy crisis is getting worse and the emission of greenhouse gases such as CO₂ has made the environmental problems become increasingly prominent. Photocatalytic reduction of CO₂ to energy compounds is considered to be one of the best ways to effectively solve this problem. Covalent organic frameworks (COFs) are a new type of crystalline porous organic polymer materials with high stability and pre-design ability, which makes COFs own great potential ability in the field of photocatalytic CO₂ reduction. This paper summarizes the research progress of COFs in the field of photocatalytic CO₂ reduction, including the introduction of different metal ions to provide the active site and increasing the photosensitive functional groups to improve their utilization of visible light. Since the research of COFs as photocatalytic CO₂ reduction catalyst is still an initial field, further exploration of synthesis, modification, and mechanism of COFs for CO₂ reduction is still promising research work.

1 Introduction

2 Covalent organic frameworks

2.1 Basic information of COFs

2.2 Application of COFs in photocatalysis

3 Basic principles of photocatalytic CO₂ reduction

4 COFs for photocatalytic CO₂ reduction

5 Conclusion and outlook

Nanozymes, a new concept first proposed by Chinese scientists, is a class of nanomaterials with biocatalytic functions. Owing to their nanostructures, nanozymes can catalyze the substrates of natural enzymes and serve as enzyme substitutes. Since the first report in 2007, over 420 research groups from 55 countries have validated this phenomenon. The discovery of nanozymes demonstrates for the first time that nanomaterials may have a unique biological effect-enzyme-like catalytic activity. As a new material, nanozyme has both the physicochemical properties of nanomaterials and catalytic function similar to those of natural enzymes, with the benefits of both. Its nanostructure not only endows nanozymes with extremely effective catalytic activity but also renders them more stable and easier to mass production. The study of nanozymes is an example of interdisciplinary cooperation, being named as one of the 2022 top ten chemical emerging technologies by IUPAC.Nanozymes have become an emerging research focus due to the collaboration of experts from diverse fields worldwide such as chemistry, enzymology, materials science, biology, medicine, and theoretical calculations. Chinese scientists lead the way in this emerging field, investigating the structure-effect relationship of nanozymes, increasing their catalytic activity by 10 000 times, realizing rational design even surpassing natural enzymes, and developing the world's first nanozyme products, as well as publishing books on nanozyme science, releasing nanozyme terminology, and establishing Chinese/international standardization. Furthermore, the new field of nanozymes has attracted a substantial number of talented young multidisciplinary and interdisciplinary scientists who are driving its strong growth by discovering more than 1200 types of nanozymes and uncovering their catalytic mechanisms.It has also evolved from the initial application in detection to nanozyme catalysis medicine, sensor detection, green synthesis, new energy, environmental protection, and many other. This article provides readers with an overview of the significant advances in nanozyme research since its discovery, including newly identified natural nanozymes. Ultimately, our goal is to see nanozymes improve human health and inspire the growth of a new field of study as they go from an idea to new materials, to technology and to products.

The opto-electronic properties of organic materials are not only dependent on the molecular structures, but also the aggregated states. In many cases, the cooperativity of intermolecular interactions can generate the new functions beyond those as single molecules. Thus, our recognition should not only limit on the level of single molecule, but pay much attention to molecular aggregates with the Molecular Uniting Set Identified Characteristic (MUSIC). Among them, organic room temperature phosphorescence (RTP) as the unique emission of organic molecules at aggregate state, demonstrating the high sensitivity and responsiveness to their aggregation behaviors in most cases. Thus, in this review, RTP property was selected as the typical optoelectronic property of molecular aggregates, and the formation processes and crucial factors have been systematical investigated and discussed. Furthermore, the related strategies can be applied into various fields, including mechano-luminescence, second-order non-linear optics, mechanochromism and OLEDS, in which the opto-electronic properties can be the static performance and/or dynamic response stimulated by force, light, heat and electric field. Finally, the controllability and predictability of molecular design of optoelectronic materials are effectively demonstrated by the established relationship between molecular structures-stacking modes and intermolecular interactions, together with the proposed effective strategies for the adjustment of molecular aggregation behaviors.

Room temperature phosphorescence (RTP) has arouse much interest due to their unique luminescence properties and wide potential applications in optoelectronics, sensing, bio-imaging and security devices. In recent years, various methods to promote phosphorescence emission at room temperature have been explored. At present, the commonly used methods for constructing room temperature phosphorescent materials with long lifetime and high quantum yield mainly center on the design of phosphorescent molecular structure and the construction of phosphorescent protective matrix. Supramolecular gel, as a new matrix for inducing room temperature phosphorescence, has attracted much attention owing to the advantages of three-dimensional network structure, thermal reversibility and stimulus responsiveness. This review focuses on metal-free room temperature phosphorescent gel and metal-containing room temperature phosphorescent gel, and summarizes current research status in recent years. In addition, a brief prospect for the future development of room temperature phosphorescent gel research is provided.

Aggregation-induced emission (AIE), conceptually coined by Prof. Ben Zhong Tang in 2001, refers to a unique photophysical phenomenon non- or weakly emissive luminogens in dilute solutions emit intensely upon aggregation. AIE can solve the aggregation-caused quenching problem that traditional fluorophores are suffering from and hold great technological values for practical applications. The past 20 years have witnessed the rapid development of AIE research, from the restriction of intramolecular rotations to restriction of intramolecular motions, and from AIE to aggregate science, and many original results have been achieved. In this review, we summarize the advances in the field of AIE and its related areas. We specifically discuss the recent progress in AIE area, including material classification, mechanism, concept derivation, property, applications, and challenges. It is hoped that this review will inspire more research into the molecular aggregate level and make significant advances in materials, chemistry and biological sciences.

Over the past decades, metal-halide perovskite solar cells (PSCs) have seen rapid development and gained extensive attention because of their excellent advantages of high light absorption coefficient, longer carrier diffusion distance, lower preparation cost, etc. By now, the champion power conversion efficiency (PCE) has reached 25.5% within a few decades. However, the PCE of the device is still lower than the Shockley-Queisser (S-Q) theoretical limit due to the fact that various non-radiative recombination losses usually take place during carrier transport process. In this review, we first introduce the device structure and working principle of PSCs, and then summarize common non-radiative recombination loss pathways, including defect-assisted Shockley-Read-Hall (SRH) recombination, interface-induced recombination, Auger recombination, band-tail recombination processes, etc. These recombination modes are the main reasons leading to low efficiency and poor stability of PSCs, and thus have drawn considerable attention among researchers. Based on the latest research works, we summarize the general regulation strategies to reduce the undesired non-radiative recombination processes for the construction of high-efficiency and stable PSCs. These efficient regulation strategies mainly include reduction of perovskite crystal defects, passivation of grain boundary defects, passivation of interface defects and optimization of energy level structure. Finally, the opportunities and challenges for the development prospects of non-radiative recombination regulation are discussed.

Hydrogen energy is an efficient and clean secondary energy that plays an irreplaceable role in realizing "carbon neutral". With the continuous expansion of hydrogen production scale and the reduction in hydrogen production cost, hydrogen energy will become a competitive alternative energy, which can further promote the transformation of China’s energy structure, reduce carbon emissions, and improve China’s energy security and resilience. China is the world’s largest producer of hydrogen, and there are three main industrial hydrogen production routes in China: fossil fuel reforming, industrial by-product hydrogen and the electrolysis of water. Other new hydrogen production technologies, such as hydrogen production from solar photolysis, hydrogen production from biomass, hydrogen production from thermochemical circulation, etc., have attracted extensive attention and investigations. In addition, hydrogen production system is complex, which is difficult for modeling and optimization. Accordingly, artificial intelligence (AI) shows unique advantages in the prediction, evaluation and optimization for hydrogen production system, which is promising and attractive. Based on the recent progress, this article summarizes several critical hydrogen production technologies into four main categories, and further proposes some perspectives for the future development of hydrogen supply structure in China. Finally, this article also reviewes the latest application of artificial intelligence in hydrogen production system to provide new insights for the development of hydrogen production technology in China.

Contents

1 Introduction

2 Hydrogen production from conventional fossil fuel reforming

2.1 Hydrogen production from coal

2.2 Hydrogen production from natural gas

3 Industrial by-product hydrogen

3.1 Pressure swing adsorption

3.2 Low temperature separation

3.3 Membrane separation

3.4 Metal hydride separation

4 Hydrogen production from water electrolysis of clean energy

4.1 AEC

4.2 PEMEC

4.3 SOEC

5 Hydrogen production from other new technologies

5.1 Hydrogen production from solar photolysis of water

5.2 Hydrogen production from biomass fermentation

5.3 Hydrogen production from thermochemical conversion of biomass

5.4 Hydrogen production from thermochemical cycle

6 Comparison of different hydrogen production methods

7 Application of artificial intelligence in hydrogen production system

8 Conclusion and outlook

Metal-organic frameworks(MOFs) are a class of crystalline porous materials formed by self-assembly of metal ions or clusters and organic ligands through coordination bonds. Due to the high porosity and functional designability, MOFs have found wide applications of which make them widely used in various fields. However, most traditional MOFs have poor conductivity, which severely restricts their development in electrical related fields. In recent years, electrically conductive MOFs, especially two dimensional electrically conductive MOFs(2D ECMOFs), have attracted a great deal of research attention due to their semiconducting or metallic properties closely-related to their unique π-π stacking and π-d conjugation structures, which have great application potentials in electrical and energy related fields such as sensors, electronics, electrocatalysts, batteries, and supercapacitors. In this review, the recent progress in conducting mechanisms, structures, synthesis strategies and applications of 2D ECMOFs are summarized and highlighted. Furthermore, future challenges and opportunities based on the current research status are prospected.

Viruses are one of the biggest threats to human health, and the outbreak of viral diseases not only poses a great threat to human health and national security, but also causes great losses to the social economy. Uncovering the mechanisms of virus infection is crucial for preventing the spread of viruses and treating viral diseases. The dynamic process of virus infection in host cells involves intricate interactions between viral components and cellular structures or organelles, but conventional methods lack the ability to acquire dynamic information on individual viruses during the infection process. Single-virus tracking(SVT) technique is a powerful approach for studying the real-time and in-situ dynamics of viral processes in live cells and it plays an increasingly important role in the study of viral infection mechanism. SVT allows researchers to obtain the dynamic information on individual viruses during the infection process, including viral entry, trafficking, and genome release, which is meaningful to study the infection mechanisms on the molecular level. In this article, we first discuss the measurement techniques, viral labeling strategies and data analysis methods for SVT, then summarize a couple of applications of SVT and finally propose the challenges and future possibilities of the SVT technique.

The enzyme-like activity of nanozymes is an emerging effect of nanomaterials. Due to the excellent physicochemical properties and unique enzyme-like activities, nanozymes have become promising functional nanomaterials. Till now nanozymes have been used in biomedical sensing, diagnosis and therapeutics, as well as environment protection. Despite of the great success achieved in the past several decades, how to efficiently design nanozymes is still one of the bottlenecks in the field, which is originated from the complicated composition and ambiguity in the active sites of nanomaterials. To tackle these challenges, this insight first summarizes the current efficient design strategies of nanozymes, such as computation-aided high throughput screening, rational design, and biomimetic design. And then, the development of bio-inspired metal-organic framework(MOF) nanozymes, particularly the structure-activity relationship study, is highlighted. At the end, combined with current research trend, several directions and inspirations for the future study are suggested to advance the nanozymes research.

Fluorescence imaging has a promising application prospect in clinical tumor tracing and intraoperative navigation, by virtue of its simple operation, high resolution, safety and real-time imaging. Though there are no targeted fluorescent probes clinically approved yet, a great number of targeted fluorescent probes are indeed under clinical trials. The very first ones are fluorescent dyes conjugated with tumor-targeting ligands, such as tumor-specific antibodies labeled with near-infrared(NIR) cyanine dye(IRDye800CW) and fluorescein isothiocyanate labeled with folic acid(EC17). In recent years, more complicated fluorescent probes, such as activatable probes and PET/fluorescent dual-modal imaging probes, have gradually entered clinical trials. Based on the latest research progress of fluorescent probes for intraoperative navigation, this review discusses receptor-mediated targeted fluorescent probes, activatable targeted fluorescent probes, NIR-Ⅱ fluorescent probes, multimodal fluorescent probes and theranostic fluorescent probes, with an emphasis on analyzing and summarizing the molecular design principles of fluorescent probes which are undergoing clinical evaluation or with the potential of clinical translation. At last, the future perspectives of fluorescent probes for intraoperative navigation are prospected.

Cancer cells that shed from solid tumor and circulate into bloodstream, namely circulating tumor cells(CTCs), are closely related to tumor metastasis. Therefore, CTCs detection is of great significance for cancer diagnosis, treatment monitoring, disease assessment and understanding of the mechanisms underlying tumor metastasis. However, CTCs are extraordinarily rare, heterogeneous, nonuniform in blood. Even if strategies for detection of CTCs in static blood collected from patients have made significant progress, they still face the tumor cell loss, cell death, low fidelity, and low sensitivity. It is essential to develop approaches available for detection of tumor cells in fast-flowing blood, allowing real-time monitoring of CTC dynamic changes under physiological conditions. In this review, we summarize techniques developed for CTC detection in vivo and their related applications. Furthermore, the advantages and disadvantages of these techniques are analyzed. Finally, future techniques for detection of CTCs in vivo are discussed and predicted.

The research focus of spintronics is to process and store the information by manipulating both the charge and spin degrees of freedom for its advantages of fast device operation, high storage density and low energy consumption. It is no doubt that developing controllable preparation method and magnetism control strategy of two-dimensional (2D) magnetic nanomaterials are of great significance and value for the fabrication of new-type spintronic devices. However, a relatively limited range of 2D magnetic nanomaterials can be achieved yet, and the preparation method as well as magnetism control strategy are relatively unvarying, which greatly hinders the development of this field. In this review, 2D magnetic nanomaterials are first categorized according to the origin of the magnetism, and induced magnetism and intrinsic magnetism in 2D nanomaterials have been introduced respectively. Then the existing preparation methods of the 2D magnetic nanomaterials, such as mechanical exfoliation, electrochemical exfoliation, chemical vapor deposition, liquid-phase synthesis and so on, are summarized in detail. Afterwards, the predominant magnetism control strategies of 2D nanomaterials are highlighted as well. Finally, the bottlenecks and future developments of this booming field are outlined and prospected.

The novel coronavirus disease(COVID-19) is a highly contagious pneumonia that has swept the world since December 2019. It has a huge negative impact on the global society, economy and life, which also seriously threatens people’s lives. Since there are no specific drugs or vaccines against COVID-19, rapid and timely detection and diagnosis are essential for controlling the epidemic. This article reviews the current detection methods for COVID-19. It mainly compares the function of computed tomography-based, nucleic acid-based and antibody-based methods for the detection of COVID-19, summarizes the advantages and weaknesses, and reviews recent research progress. Virus isolation is the gold standard for detecting viral infections but requires strict conditions that most laboratories and hospitals cannot reach; CT examination allow us directly see the symptoms but with a limitation of low specificity; nucleic acid testing provides direct evidence and is currently the main method for COVID-19 but have a false-negative rate; antibody testing is indirect evidence and adapt to carry out screening work, but it cannot be used in the early stage of infection and may get false-positive and false-negative results. Joint use and comprehensive interpretation are proposed to be complementary in terms of technology and time difference, which will play an important role in identifying patients, monitoring disease progress and investigating epidemiology. The future development, research priorities and challenges are addressed.

Metal halide perovskite has become a promising semiconductor material due to its diverse chemical structure and excellent optoelectronic properties. After introducing organic chiral molecule into the perovskite framework, chiral perovskite nanomaterials can be obtained, which has greatly promoted the rapid development of smart optoelectronic materials and spin electronic devices. This paper reviews the latest research progress in the construction of chiral perovskite nanomaterials, including one-dimensional chiral perovskite nanowires, two-dimensional and quasi-two-dimensional chiral organic-inorganic hybrid perovskite nanosheets, three-dimensional chiral perovskite nanocrystals, chiral perovskite nanocrystals induced in supramolecular assembly system and the mechanism for the formation of chirality. It is worth noting that different types of chiral perovskite nanomaterials show excellent optoelectronic properties and huge application prospects in terms of circular dichroism, circularly polarized luminescence, ferroelectricity and spintronics. However, the research on chiral perovskite nanomaterials is still in its infancy, and many of its mechanisms are still controversial, and many basic and applied work needs to be carried out.

Air pollution is a major challenge for the humankind. Under the highly complex air pollution conditions in China, strong homogenous nucleation and multiphase heterogeneous processes coexist, coupling with strong atmospheric oxidizing capacity and ozone pollution. This complex air pollution, different from the “London smog” and the “Los Angeles photochemical smog”, is a new type of “haze chemistry smog” pollution. “Haze chemistry” distinguishes from traditional homogeneous chemistry by surpassing its existing theoretical understandings. It is a type of air pollution chemistry that comprehensively studies the gas-liquid-solid multiphase processes, revealing the formation mechanism of PM_2.5 and the non-linear relationship between PM_2.5 and O₃ under typical multi-medium complex air pollution conditions. Understanding “haze chemistry” processes is crucial for precise control of complex air pollution in China and other countries. Here, we propose and summarize the concept of “haze chemistry”, and discuss its further improvement, development, and application.

CRISPR (Clustered regularly interspaced short palindromic repeats) technology is a revolutionary gene editing tool developed in recent years, which has quickly become a cutting-edge technology in the field of biology and medicine and widely used in gene function research and gene therapy. In addition to excellent gene editing capabilities, various new functions are also being continuously created with the efforts of scientists from different fields. CRISPR has excellent sequence recognition properties, nucleic acid cleavage ability, and is easy to program and design. Therefore, it exhibits unique charm in the field of bioanalytical chemistry, and has made breakthrough progress in virus detection, clinical diagnosis, and single cell imaging analysis. At present, there are many types of detection methods using CRISPR technology. Therefore, we summarize and classify the current research status of CRISPR analysis and detection methods, and look forward to its development trend.

Aggregation of β-amyloid (Aβ) has been considered as an important factor leading to Alzheimer’s disease (AD). Previous studies have focused on the full-length unmodified Aβ_1-40 and Aβ_1-42. In recent years, it was found that a variety of truncated and modified Aβ species co-exist in AD patients’ brain. These Aβ species contributed to the progression of AD and should not be overlooked. For example, the emergence of pyroglutamated Aβ and phosphorylated Aβ is considered as symptoms of AD. And the most abundant Aβ species in AD patients’ brain should be Aβ_4-40/42, which has similar aggregation properties and toxicity with Aβ_1-40/42. Due to the elevated oxidative stress in AD patients’ brain, tyrosine nitration, dimerization and methionine oxidation were also identified in Aβ sequence, resulting in different properties. We review here the production, structure and toxicity of different Aβ species and summarize their possible roles in AD pathology.

The ent-kaurane diterpenoids, widely distributed in terrestrial plants, represent an important group of tetracyclic diterpenes with diverse scaffolds and varied bioactivities. More and more studies have revealed that these compounds possess potent antitumor, antibacterial and anti-inflammatory activities. The tetracyclic ent-kaurane diterpenoids have attractive structural diversity owing to intramolecular cyclization, oxidative cleavage and rearrangements of their parent compounds. As a result, the total synthesis of ent-kaurane diterpenoids has received great attention from synthetic community during the past decades. This review describes the recent progress in this field, which includes total synthesis of C-20 non-oxygenated ent-kauranes such as(+)-lungshengenin D and pharicins A-C; total synthesis of C-20 oxygenated ent-kauranes such as maoecrystal P, eriocalyxin B, neolaxiflorin L and xerophilusin I; total synthesis of seco-ent-kauranes such as sculpomeatin N, trichorabdal A, maoecrystal Z, enmein, isodocarpin, sculponin R, londirabdiol, longirabdolactone and effusin; and total synthesis of nor or rearranged-ent-kauranes such as jungermannenones B and C, maoecrystal V, jungermatrobrunin A and kauradienone.

In this paper, the separation, synthesis and biological activities of glycosylated iminosugars are systematically summarized. The naturally occurring glycosylated iminosugar products can be classified into five types according to their iminosugar units. Most of them have important biological activities, especially glycosidase inhibitory activities. Potential pharmacological activities of these compounds promote the study of synthetic strategies. According to the construction methods of glycoside bonds, these strategies can be roughly divided into enzyme catalyzed transglycosylation and chemical synthesis, of which the main difference is reaction condition. Enzyme catalyzed transglycosylation features mild reaction conditions and possible avoidance of protection groups, but the reaction efficiency and selectivity still need further improvement. Many synthetic strategies for ordinary glycosides can be used in chemical synthesis of glycosylated iminosugars, and are applicable for almost all synthetic targets. However, burdensome protection-deprotection procedures pull down the efficiency of chemical synthesis. The development of synthetic strategies have promoted the design and synthesis of the natural products and their analogues, which greatly enriches the variety and biological activities of glycosylated iminosugars. Generally, biological activities of glycosylated iminosugars are influenced by both the glycosyl groups and the iminosugar units. As the cross-domain of traditional carbohydrate chemistry and iminosugar chemistry, the structural diversity of glycosylated iminosugars provides excellent parent skeletons for the development of highly active and selective lead compounds, which endows these compounds with potential applications in drug discovery.

As fluorescent sensing materials, fluorescent polymers not only have many sensing units, high brightness and good light stability, but also facilitate the fabrication of fluorescent sensing films, which are easy to implement devices. Therefore, fluorescent polymers have been widely studied and applied in fluorescence detection of explosives. In recent years, a large number of fluorescent polymers with various functional units have been developed, and their structures have evolved from common linear structures to branched and porous network structures, which have effectively improved the sensitivity, selectivity and response rate of explosive detection. This review is aimed to summarize the research progress on fluorescent polymers used for detection of explosives, including linear polymers, branched polymers and porous polymers. The emphasis of this review is especially focused on the structure design strategies, functional characteristics and sensing performances of typical linear conjugated and non-conjugated polymers, dendrimers and hyperbranched polymers and amorphous and crystalline porous polymers. Finally, the future opportunities and challenges of fluorescent polymers in application of explosive detection are presented.

Azo compounds are a class of trans-cis(E/Z) photoisomerization compounds which have advantages of simple synthesis, high isomerization rate and efficiency, and resistance to photobleaching. Due to their outstanding photoisomeric properties and ability to form stable inclusion complexes with macrocyclic hosts, azo compounds have shown great potential application in many fields. In this review, we show the design principles, assembly mechanism, application and development of the photo-controlled supramolecular assemblies in topologically morphological regulation, drug delivery, smart materials and so on, which are constructed by host-guest interaction using azo modified cyclodextrin, bis-cyclodextrin bridged by azobenzene, crown ether derivatives, azo aromatic macrocyclic compounds as the hosts or azobenzene or azobenzene derivatives as guests. At the same time, we also discuss the opportunities and challenges of the development of such supramolecular assemblies, and hope to further promote the development of intelligent supramolecular assemblies.

As the main greenhouse gas in the atmosphere, carbon dioxide(CO₂) has caused a series of environmental and energy-related problems worldwide. Therefore, there is an urgent need to develop a variety of methods to capture CO₂ and convert it into useful chemical products, thus effectively improving the environment and promoting sustainable development. In the past decades, metal-organic frameworks(MOFs) have shown prominent heterogeneous catalytic activity due to their multiple active sites, large BET surface area, structural diversity and easy functionalization. These characteristics endow MOFs catalysts with unique advantages in the field of CO₂ chemical fixation. The application of MOFs catalysts in organic synthesis involving CO₂, such as chemical reactions of CO₂ with epoxides, terminal alkynes, propargyl alcohol and propargyl amine are reviewed herein, and the structure-function relationship between the active sites within MOFs and catalytic performances are illustrated.

Circulating tumor DNA(ctDNA), the main item of liquid biopsy, is DNA fragments from tumor genome that carries certain characteristics(including single nucleotide variation, deletion, insertion, rearrangement, copy number variation, and methylation) in the human blood circulation system. It mainly originates from apoptotic or necrotic tumor cells. The detection and analysis of ctDNA can provide genomic information in tumors, such as copy number variation, single nucleotide mutation, and methylation enrichment across the genome. It has a certain correlation with tumor size and development and considered as an emerging and promising tumor biomarker for cancer progression, reoccurrence, and routine monitoring after surgery. Compared with other tumor markers, the isolation method is relatively simple due to the stability of ctDNA. However, the extremely low abundance of ctDNA, the high content of background cell free DNA(cfDNA), the large difference between individuals, and the need of predicted detection sites in advance make it necessary to analyze ctDNA in a comprehensive way. Herein, we summarize the recent progress on ctDNA detection from digital PCR to next generation sequencing, including some commercialized apparatuses and certain methods that have recently been developed.

Diphenylalanine dipeptide is a key recognition sequence of the β-amyloid protein that causes Alzheimer's disease. Due to its simple structure and excellent assembly performance, diphenylalanine dipeptide has been becoming a “star” building block in the field of molecular assembly to construct many functional materials. At present, a large number of researchers have been carried out on the controllable assembly of diphenylalanine dipeptide and its derivatives, including molecular design, structural regulation and functional applications. In recent years, through molecular assembly, our group has achieved the controlled preparation of diphenylalanine dipeptide-based assemblies by modulating various kinds of molecular interactions including Schiff-base covalent bonding, electrostatic attraction, hydrogen bonding and pi-pi stacking. In particular, we have explored optical properties and potential applications of such assembled diphenylalanine dipeptide-based materials. This review will mainly introduce the research progress mentioned above. Firstly, the preparation methods of diphenylalanine-based photofunctional materials through covalent, non-covalent or combined assembly are analyzed, compared and discussed. Then, the applications of these assembled materials in actively optical waveguiding, optical imaging for tracing drug delivery, photodynamic therapy for cancer treatment, patterned photofabrication and biomimetic photocatalysis are introduced in detail, respectively. Finally, we give a summary and propose the possible development trend of diphenylalanine dipeptide-based assemblies.

The classic Friedel-Crafts acylation uses acid chloride or anhydride as acylating agents, and Lewis acid as catalysts. The large amount of Lewis acid applied and HCl generated in the acylation reaction must be treated. Acid chlorides are sensitive to moisture, and danger might occur during storage and usage. Acylation using carboxylic acids in the presence of trifluoroacetic anhydride as acylating agents does not require conversion of the acylating agents into acid chloride, anhydride or amide. Furthermore, the trifluoroacetic anhydride and trifluoroacetic acid generated can be easily recovered by distillation. Therefore, it can effectively solve the problems associated with the classic Friedel-Crafts acylation. This review summarizes the developments of the acylation process using carboxylic acids in the presence of trifluoroacetic anhydride as acylating agents, and their applications in the syntheses of organic functional molecules, drug molecules and natural products during the last two decades.

“Coordination space” is the space with specific structure and functions, which is defined by the coordination bonded structural elements of inorganic-organic hybrid system. This concept provides a new perspective for the research on the targeted construction and modulation of coordinative hybrid materials. As typical inorganic-organic hybrid materials, Metal-Organic Framework (MOF) and Metal-Organic Cage (MOC) have attracted widespread attention in recent years. The key point of targeted construction and regulation of could be regarded as the design of their coordination space. The stimuli-responsive MOFs possess dynamic coordination space, which promote their potential applications in adsorption/separation, sensing, drug delivery, and related fields. Based on the well-developed research of dynamic of metal-organic framework, herein we briefly introduce the recent progress in dynamic coordinate space, including the structure foundation and stimulating factors for the achievement of dynamic behaviors, the relationship between the structure and properties of this kind of material, which could be instructive useful references for related research investigation.

Hydrogen (H₂) gas acquires a high combustion calorific value (285.8 kJ/mol) and only produces water during combustion, so it is considered as an ideal energy carrier. Photocatalytic H₂ evolution from water by simulating the structure and function of active center in natural photosynthesis is not only an important way to convert solar light into chemical energy but also an essential part of artificial photosynthesis. Here, we summarize the recent major progress of this field and forecast the development and potential applications of artificial photosynthetic H₂ production in the near future.