Optical analysis is non-destructive, real-time with a specific spatial resolution, which has been developed as an essential technology to study the occurrence, development, diagnosis, and treatment of diseases. It contains fluorescent (FL), bioluminescent (BL) and chemiluminescent (CL) methods. Among them, CL probes with an adamantane-dioxetane chemiluminescence (AD-CL) scaffold attracted much attention. Recently, significant improvement on these probes has been achieved with the elimination of external light source, low phototoxicity, high sensitivity, and a facile system without additional reagents, such as oxidants. Until now, the CL probes were further developed with special modifications and new synthesis routes based on the AD-CL scaffold, realizing the detection and optical imaging of various biomolecules in living systems with enhanced properties. Herein, the recent research progress on AD-CL probes has been reviewed. The review is divided into two parts. The first part will mainly introduce the molecular modification strategy of AD-CL probes and the second part will focus on their application in several cases.

Helical motion can be observed on all length scales, which affects a variety of life processes, including biological reproduction, foraging, locating favorable environments and detecting nutrient gradients. The development of artificial swimmers that can perform helical motions not only has a wide range of applications and improves our understanding of the laws and mechanisms of biological swimmers' motions, but also contributes to the design of novel robots and improves the efficiency of robotic motions. In this paper, we first summarize artificial swimmers that can perform helical motions in artificial systems designed by using the rotation and flapping of microbial flagella/cilia as an inspiration source. Then diverse artificial swimmers that perform helical motions in recent years are introduced by different sources of driving force. Finally, the unresolved questions and prospect are tentatively presented in this field.

Ascorbic acid (AA), as a necessary biological small molecular substance to maintain the normal function of human body, directly and indirectly participates in many key biological reaction processes of human body. Electrochemical detection of AA has been a hot spot of sensing research in recent years due to the advantages such as fast response, high sensitivity and simple operation. In this review, the working principles of different sensors of AA are systematically and comprehensively introduced, and the recent research progress of electrochemical sensing of AA is reviewed. By comparing different materials based AA sensors performances, the advantages and defects of corresponding materials are analyzed and summarized by combining with the materials properties. Lastly, the outlook of development direction and trend of AA electrochemical sensing is given.

Metallization of polymer surface plays an important role in conductive interconnect, electromagnetic shielding, thermal management, decoration and protection of electronic products. Compared with vacuum sputtering and other methods, electroless plating has advantages of uniform coating, low cost and easy large-scale production. In recent years, polymer used for electronic applications such as epoxy resin, polyimide (PI), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polyurethane (PU), polystyrene (PS) have been actively studied. Coarsening treatment has obvious influence on the binding force of coating and the degree of coating on the substrate. At the same time, the activation method affects the speed and thickness of electroless plating. In the surface pretreatment of polymer electroless plating, coarsening and activation methods have a great influence on the coating properties, especially for LCP and other polymers that will be used in 5G equipment. In polymer electroless plating pretreatment, coarsening processes such as chemical etching, plasma treatment and graft treatment, as well as activation processes such as ion adsorption reduction, catalyst direct adsorption and ink printing also have many new developments. In this paper, the latest development of coarsening and activation pretreatment of various polymer substrates in electronic applications is summarized, in order to provide reference for the development of electroless plating technology for electronic circuits.

Light-driven cholesteric liquid crystals are soft intelligent photonic crystal materials, which change their optical properties upon irradiation of light. The molecules are organized into helical superstructures to selectively reflect the circularly polarized light with the same handedness as the light-driven cholesteric liquid crystals. By modulating the helical superstructures with light stimuli, the wavelength or polarization of the selective reflection is tuned. Light-driven handedness inversion of helical superstructures in cholesteric liquid crystals is currently in the limelight. The inversion of handedness alters the chirality of the circularly polarized light, which has wide potential for applications in tunable filters, anti-counterfeiting technologies, circularly polarized lasers, and 3D displays. However, inducing the handedness inversion of cholesteric liquid crystal still remains a challenge because the energy barrier between the opposite twist sense is difficult to overcome. It is necessary to figure out the universal strategies for designing light-driven cholesteric liquid crystal systems with reversible handedness inversion. This review mainly focuses on the development of the light-driven cholesteric liquid crystals with handedness inversion. The reported strategies for controlling the handedness are summarized, including the handedness inversion induced by reverse molecular chirality upon photoirradiation and introduction of chiral conflict. The reverse molecular chirality in different chiral molecular switches with tetrahedral, planar, or axial chirality induced by azobenzene, dithienylethene, overcrowded alkene, or cyano-functionalized diarylethene is concluded. During the photoisomerization process, the changes of conjugation, geometry, and dipole moment are analyzed. The strategies to introduce chiral conflict in cholesteric liquid crystals are demonstrated, and the mechanism of chiral conflict to facilitate handedness inversion is explained. Most importantly, the existing challenges and opportunities toward the systems are discussed.

Due to the unique merits of long luminescence lifetime and environmental sensitivity, room temperature phosphorescence (RTP) has demonstrated great potential in many fields, e.g., chemo/biosensing, bioimaging, biomedicine, and advanced optical anti-counterfeiting and encryption. In recent years, non-metal doped solid state room temperature phosphorescent (RTP) carbon-dots (CDs) have attracted broad attention because of their facile preparation, chemical inertness, low toxicity, easy surface modification, and so on. However, in an aqueous environment, their RTP emissions suffer from serious triplet quenching that induced by dissolved oxygen and water molecule. How to stabilize the triplet state in aqueous phase is the key to establish their RTP emission, and thus it is necessary to look back the state-of-the-art knowledge of CDs-based water-soluble RTP materials. In this review, in light of the recent advance, we summarize and discuss their synthesis strategies (e.g., inorganic salt melting, SiO₂ coating, polymer combination, and hydrogen bond network stabilization), and relevant applications in sensing, imaging and anti-counterfeiting, and finally propose the challenging and future prospects. To the best of our knowledge, this is the first review on the synthesis and applications of hydrophilic RTP materials based on CDs. We hope that this review will provide inspiration for the further fabrication and versatile biological uses of CDs-based RTP materials.

Multicomponent assembly includes multiple components that can form self-assemblies, which is a common phenomenon in natural processes. We can analyze the structural characteristics embedded in the natural supramolecular structure and design innovative materials according to the predicted molecular interactions. However, due to the limited understanding of the nature of the molecules, the design of low molecular weight hydrogels (LMWGs) with controllable hierarchical structure is still facing certain difficulties, and it is far from the naturally formed high-level complex living system. In the field of multicomponent supramolecular chemistry, it is necessary for us to study the structure and function of multicomponent self-assembly networks by using the method of system theory. In addition to understanding the properties of component molecular monomers, we also need to study the chemical networks formed by component molecules for the better understanding of nature. When self-assembly is triggered in a multicomponent system, there are usually three assembly pathways, namely, co-assembly, self-sorting and multidimensional hierarchical combination of assemblies or heterojunction. These three assembly systems compete with each other but may also coexist, resulting in the complexity and multiple responsiveness of the multicomponent assembly system. Therefore, the design and assembly structure prediction of the multicomponent assembly building blocks or assembly systems are also very challenging. The high-level and multicomponent assembly process allows multiple self-assemblies to operate cooperatively and orthogonally, and has precise spatial control. The self-sorting is the basis of many related (biological) chemical processes (such as phase separation, kinetic analysis or self-replication), which can be narcissistic or social. The study of self-sorting assembly in multicomponent assembly system is of great significance for deepening the understanding of the relationship between components and molecules, realizing the control of the network, and realizing the controllable construction of high-level complex assembly system. In this paper, the characteristics and research methods of multicomponent assembly are reviewed, and the research results of self-sorting in the fields of self-assembly characteristics and control of multicomponent assembly are displayed and discussed, in order to promote the understanding and in-depth research in this field.

The transition towards electric vehicles (EVs) has resulted in a proliferating demand for lithium-ion batteries (LIBs). The continuous growth in the EV industry results in a colossal number of LIBs being discarded after reaching their end-of-life. Researchers have carried out numerous investigations on the extraction of valuable metals from spent LIBs. The recycling processes have mainly been concerned with the recovery of the valuable metals of cobalt and nickel, with less attention being placed on lithium recovery. With the imbalance of the supply and demand of lithium resources, research on selective recovery of lithium from spent LIBs has increased in recent years. This paper provides a comprehensive overview of the high-temperature selective conversion, selective leaching, mechanical and electrochemical recycling methods that facilitate selective lithium recovery. It provides recommendations for future research and development to enhance the selective extraction of lithium from spent LIBs.

Changes in volatile organic compounds concentrations in human breath are closely related to certain diseases, and the diagnosis of diseases by analyzing volatile organic compounds in human breath is a non-invasive, and easy-to-use tool that has received increasing attention in recent years for applications in disease diagnosis and early screening. There are currently two main types of equipment for detecting volatile organic compounds in exhaled breath: mass spectrometry-based analytical instruments and gas-sensitive sensors. With easy integration, miniaturization, low cost, and simple operation, gas-sensitive sensors have broad application prospects in the future diagnosis and early screening of large-scale population diseases. This review systematically describes the working mechanism of gas sensors, sensor performance, the current status of application of different sensitive materials and the application of different gas sensor types in human breath detection, the types of volatile organic compounds in human breath that are associated with some diseases are also introduced, which is followed by a brief introduction to the means of breath sampling and the data processing methods currently in use. Finally, the problems of current gas sensor technology in breath detection are pointed out, and the prospects of gas sensor technology in human breath detection are foreseen.

Photovoltaics are one of the strategic solutions to solve energy and environmental problems. The state-of-the-art solar cells always photo-induce electrons and generate electricity by the photovoltaic effect under the illumination of sunlight or indoor light, but the power output is still extremely low in dark-light or nonluminous conditions such as rainfall and night. The hybrid energy harvesting solar cells that can persistently output electricity in multiple weather are expected to further increase total power output and generating time. This perspective focuses on discussing the coupling principles of photovoltaic effect with hydrovoltaic effect, triboelectric effect, light storing-emitting effect, piezoelectric effect and thermoelectric effect in hybrid energy harvesting solar cells and summarizing the recent advances of these novel solar cells as well as analyzing the future development of this field.

Hydrogen peroxide (H₂O₂) is a promising energy carrier and an environmentally friendly oxidant which is widely used in industry and health fields including organic synthesis, drinking water treatment, wastewater treatment and medical hygiene. With the promotion of environmental protection requirements, the demand for H₂O₂ is expected to increase substantially. H₂O₂ production by the traditional anthraquinone method (AQ) has a tedious process and pollutes the environment with a large amount of organic matter. In contrast, photocatalytic H₂O₂ production technology is a green process which uses O₂ and H₂O as raw materials, solar energy as energy source, and semiconductor as photocatalyst, with some distinct advantages, e. g, mild reaction conditions, simple and controllable operation, and no secondary pollution. Nowadays, the production of H₂O₂ via photocatalytic route has attracted extensive attention. This review introduces the mechanism of photocatalytic H₂O₂ production and the reasons for its low efficiency_. The typical photocatalyst systems and strategies for enhancing photocatalytic efficiency in H₂O₂ production are intensively summarized and discussed. Finally, the perspective for the future development of photocatalytic H₂O₂ production is proposed.