Carbon dots (CDs), with particle size less than 10 nm, are a new type of zero-dimensional photoluminescence nanomaterials. Due to the obvious advantages of adjustable fluorescence emission and excitation wavelength, light stability, low toxicity, good water solubility and biocompatibility, etc., CDs have been widely researched in recent years. As a treasure of ancient Chinese science, Traditional Chinese medicine (TCM) is rich in various active ingredients and plays a variety of pharmacodynamic effects, which has been used for thousands of years. TCM-CDs prepared with TCM as carbon source can create some special functions, and then may play a greater medicinal value. In this paper, the synthesis of TCM-CDs and its application in biological imaging and medical therapy are reviewed. Firstly, different synthetic methods of TCM-CDs (including hydrothermal, pyrolysis, solvothermal and microwave assisted method) are introduced in detail, and their advantages and disadvantages are compared. Subsequently, the latest research on TCM-CDs in biological imaging and medical treatment is comprehensively analyzed. This paper focuses on the application of imaging different types of cells in vitro and the distribution and uptake of TCM-CDs guided by imaging in vivo (mice, zebrafish, etc.). In addition, the intrinsic pharmacological activities of these TCM-CDs (including antibacterial, anti-inflammatory, hemostatic, antioxidant and anticancer, etc.) and their mechanisms are also discussed in order to improve and promote their clinical application. Finally, the importance of TCM-CDs research, the main problems and challenges in this fields and the future development direction are summarized and outlooked.

Metal-organic frameworks (MOFs) are a new generation of crystalline porous materials with void space structures constructed from metal ions or clusters and organic ligands through coordination bonds, and have been a hot research topic in the field of coordination chemistry over the past two decades. As the novel multifunctional materials, MOFs have been widely used in various fields due to their high porosities, low densities, large surface areas, tunable pore sizes, diverse topological structures and tailorabilities. Although MOFs have many advantages, most of MOFs materials have relatively lower water and chemical stability and cannot maintain their structures under harsh conditions, which greatly restrict their practical applications under moisture-rich conditions. Therefore, chemically stable MOFs materials will have greater application prospects. In recent years, researchers have carried out a lot of exploration in improving the chemical stability of MOFs, and developed some excellent methods to synthesize chemically stable MOFs. This review will mainly focus on the latest research progress in the syntheses of chemically stable MOFs during the past five years.

The discovery and creation of new carbon materials have motivated the evolution of technology. Carbon is one of the central elements, due to the characteristics of carbon atoms and varying electron configurations, diverse molecules will be discovered and formed. The structures and arrangements of carbon atoms in molecules have a significant impact on their properties. Nanocarbon molecules, as novel carbon materials with excellent properties, have found promising applications in nanotechnology, electronics, optics, and biomedical fields. In the past four decades, the discovery and creation of new variety of nanocarbon materials have opened up a new path to advanced science and technology. This paper focuses on the study of the structural characteristics of nanocarbon molecules with novel topological structures, and the way to achieve full synthetic control over these structures that are reported in recent years.

In recent years, with the development and popularization of Internet and artificial intelligence, the flexible pressure sensor with light, convenience and excellent electronic performance, as the core device of wearable electronic equipment, has a increasingly broad market. Flexible pressure sensors have attracted extensive attention in electronic skin, motion detection, medical monitoring and man-machine interface because of its flexibility, folding and excellent sensing performance. The construction of micro-nano structures is the key to improve the sensitivity and sensing performance of pressure sensors. Based on this, the sensing mechanism (piezoresistive, capacitive, piezoelectric, triboelectric) and key performance parameters (sensitivity, pressure response range, detection limit, response/recovery time, stability of circulation and linearity, etc.) of the high-sensitivity pressure sensors were summarized. Then, research progress of flexible pressure sensors using substrates to construct surface micro-nano structures (micro-convex structure, bramble structure and fold structure) and using conductive materials to construct micro-nano structures (micro-sphere structure, urchin structure and cellular structure) were compared and concluded. Furthermore, the application status of high-sensitivity flexible pressure sensors based on micro-nano structure in pulse detection, electronic skin, motion detection and man-machine interface was concluded. Finally, from the perspective of future application, the challenges and development direction of high sensitivity flexible pressure sensor are summarized.

Diels-Alder (DA) reaction is temperature-reversible, catalyst-free, efficient and fast with none harmful products, making it a favorable choice to build a self-healing and recyclable dynamic covalent elastomer network. However, classic DA reactions (such as the reaction between furan and maleimide) still have the problems of long reaction time, low efficiency and poor chemical modularity. Recent studies have shown that the efficient cascade of HDA reaction (Diels-Alder cycloaddition reaction containing heteroatom sulfur) and RAFT polymerization can be realized by highly reactive dienes reacting with specific RAFT agents, which can reduce the reaction temperature and time of DA. By virtue of the RAFT polymerization, it can control polymer molecular weight and its distribution at the same time. RAFT-HDA cascade reaction shows wide potential applications especially in the preparation of high molecular weight block or grafted polymer and surface modification. In this paper, the research and application of HDA-RAFT cascade reaction in the past 15 years are summarized, existing problems and solutions are discussed and the future development of this field is also prospected.

Compared with oral administration and injection administration, the microneedle transdermal delivery system has the characteristics of high efficiency, safety and painless administration. In particular, the stimuli-responsive polymer microneedle systems exhibit good biocompatibility and can be realized according to the micro-changes in the environment. The function of percutaneous local and systemic intelligent drug delivery in time and space is currently an international frontier research topic. This paper focuses on the research of stimulus-responsive polymer microneedles at home and abroad in the past ten years, and focuses on the evolution of polymer microneedles, the types of internal and external environmental stimulus response and its response structure-activity mechanism. In addition, the preparation and characterization of microneedles and the application of microneedle system in the fields of biomedicine delivery, tissue and organs, dermatology and medical beauty are described in detail. The stimulation-responsive polymer microneedle system has the advantages of simple use, adjustable mechanical properties and precise targeted drug delivery, which has great research significance in the field of percutaneous targeted drug delivery. In the future, the biological in vivo load and industrial application of standardization are the direction of continuous efforts and progress of researchers.

Cocaine has become one of the most dangerous and illicitly abused drugs today due to the adverse effects of long-term cocaine abuse, such as arrhythmia, myocardial infarction, stroke, hypertension and aortic stiffness. Traditional cocaine chromatographic analysis methods have disadvantages such as time-consuming, cumbersome sample processing and complicated operations. Therefore, improving cocaine detection methods has a certain positive impact on crime-fighting and medicine-developing. Due to the accuracy and portability of biosensors, immunological and aptamer technologies for specific capture of targets have become an important direction for cocaine detection. In this review, different types of cocaine biosensors in recent years are mainly described, covering the research progress of cocaine detection based on electrochemical, fluorescence, colorimetric and other methods. The immuno- and aptamer-based biosensors of cocaine are reviewed, the advantages, disadvantages and development directions of cocaine sensors are summarized.

Copper-based small-pore zeolites catalysts are the promising candidate catalysts for NO_x abatement in current diesel vehicles with Chinese VI standards, due to the excellent NH₃-SCR catalytic performance, hydrothermal stability, nitrogen selectivity and wide temperature window. However, the catalytic activity of copper-based small-pore zeolites is still significantly affected by sulfur oxides emitted from diesel vehicles, and even the irreversible deactivation occurs. The SO₂-poisoning of Cu-based small-zeolites is mainly due to the accumulation of surface ammonium sulfate and sulfation of Cu active site sites. In this review, the research status of the structure and active sites of copper-based small-pore zeolites catalysts is summarized, and the sulfur poisoning mechanism of copper-based small-pore zeolites catalysts is discussed. Moreover, the research advance in the improvement of sulfur resistance of catalysts and the regeneration of sulfur-poisoned catalysts is also illustrated. The systematic understanding of mechanism of sulfur poisoning and regeneration is important for the design of novel, efficient catalyst. It is pointed out that the study on sulfur poisoning mechanism and regeneration mechanism of copper-based small-pore zeolites catalysts, as well as the synergistic effect of various poisoning factors and corresponding deactivation mechanism, are the main research directions for copper-based zeolites to be practically applied to ultra-low emission of nitrogen oxides in diesel vehicle exhaust in the future.

The selective ionic removal from water or wastewater by newly-developed adsorbents has been intensely investigated around the world since 1960s. These selective ionic adsorbents were used to control the concentrations of specific ions in drinking water or wastewater in the presence of plentiful coexisting ions to prepare quality drinking water or avoid ecological hazards in natural waterbodies due to wastewater discharge. Due to remarkable market demands and wide application prospects, this topic still generates numerous amazing findings in terms of international publications in recent decade. Besides the history, the present status and the research bias, this paper lays particular emphasis on the four selective ionic removal strategies involved in previous studies (i.e., the molecular imprinting technology, the soft and hard acid base theory, the non-electrostatic interaction theory, and the self-inhibition theory of competitive ions), including their mechanisms, histories, and adsorbent preparations and applications. Finally, this review also prospects the future research directions. This review provides overall information for the further development of selective ionic adsorbents for water or wastewater treatment.

Solid oxide fuel cells (SOFCs) are power generation devices with high efficiency and low emissions. The high operating temperature (700~900 ℃) has impeded the wider adoption of SOFC stacks and limited their lifetime. This has motivated intense research efforts in developing SOFC stacks which can operate at lower temperatures. The thin electrolytes with a thickness smaller than 10 μm could shorten the ion conductive paths and reduce the associated ohmic loss, effectively improving the electrical performance of the low-temperature SOFC. The electrophoretic deposition process has the advantages of low cost and fast manufacturing speed. It is a potential candidate for large-scale commercial production of electrolyte thin films for low-temperature SOFC. In the present article, the research progress of electrophoretic deposition during the past ten years has been summarized. The key results and achievements for the important procedures of the electrophoretic deposition process, which are respectively substrate selection and pretreatment, stable suspension preparation, bubble elimination and heat treatment process, are also discussed and analyzed. The suggestions for future development of the electrophoretic deposition are also provided based on the requirements of large-scale commercialization of thin electrolyte for low-temperature SOFC.