Persistent room-temperature phosphorescence (p-RTP) has drawn extensive attention due to its unique photophysical processes and promising applications in organic light-emitting diodes (OLEDs), [1] biological areas, [2] chemical sensors, [3] optics, [4] and anticounterfeiting technology. [5] Currently, p-RTP systems, however, are normally restricted to inorganic compounds. [6] As promising alternatives, pure organic p-RTP luminogens take advantages of low cost, wide variety, environmental friendliness, good biocompatibility, appreciable stability, and good processability, [7] allowing a wide range of optoelectronic and biological applications. [2] The triplet excitons of organic luminogens, however, are prone to nonradiative relaxations through vibrational stretching and external quenching (i.e., O 2 ), making it difficult to achieve efficient p-RTP. [8] To overcome such barriers, generally, two attempts are endeavored: one is to boost the spin-orbital coupling (SOC) and subsequently promote the intersystem crossing (ISC) processes through incorporation of heavy atoms, [9] heteroatoms, [10] or aromatic carbonyls; [11] the other is to stabilize the triplet excitons in a rigid environment by suppressing nonradiative decay pathways to activate the RTP emission, [12] such as crystal formation, [13] embedding into rigid hosts, [14] polymer assistance, [15] and metal-organic framework (MOF) coordination. [16] Despite exciting advancements have been made in the past few years, fabrication of efficient and robust p-RTP still remains a challenge. First, the p-RTP efficiency (Φ p ) of reported phosphors with the lifetime (〈τ〉 p ) of several hundred milliseconds are generally below 5%, [11a,13a] and moreover, robust p-RTP at complex and changing environments is rare, even though it is essential for diverse applications in data recording, encryption, anticounterfeiting, and bioimaging. [17] For example, when applied in molecular imaging, owing to their long-lasting nature, p-RTP materials can eliminate the need for light irradiation and circumvent the troublesome interference of nanosecond tissue autofluorescence, thus permitting much clearer and more reliable bioimaging with high signal-to-noise ratios. Current methodologies toward biomedical applications, however, mainly adopt nanocrystallization or top-down nanoparticle Pure organic persistent room-temperature phosphorescence (p-RTP) under ambient conditions is attractive but challenging due to the slow intersystem crossing process and susceptibility of triplet excitons. Fabrication of pure organic RTP luminogens with simultaneously high efficiency and ultralong lifetime still remains a daunting job, owing to their conflicting requirements for the T 1 nature of (n,π*) and (π,π*) characteristics, respectively. Herein, a group of amide-based derivatives with efficient p-RTP is developed through the incorporation of spin-orbital-coupling-promoting groups of carbonyl and aromatic π units, giving impressive p-RTP with lifetime and efficiency of up to 710.6 ms and 10.2%,...

A novel light-driven Au-WO@C Janus micromotor based on colloidal carbon WO nanoparticle composite spheres (WO@C) prepared by one-step hydrothermal treatment is described. The Janus micromotors can move in aqueous media at a speed of 16 μm/s under 40 mW/cm UV light due to diffusiophoretic effects. The propulsion of such Au-WO@C Janus micromotors (diameter ∼ 1.0 μm) can be generated by UV light in pure water without any external chemical fuels and readily modulated by light intensity. After depositing a paramagnetic Ni layer between the Au layer and WO, the motion direction of the micromotor can be precisely controlled by an external magnetic field. Such magnetic micromotors not only facilitate recycling of motors but also promise more possibility of practical applications in the future. Moreover, the Au-WO@C Janus micromotors show high sensitivity toward extremely low concentrations of sodium-2,6-dichloroindophenol (DCIP) and Rhodamine B (RhB). The moving speed of motors can be significantly accelerated to 26 and 29 μm/s in 5 × 10 wt % DCIP and 5 × 10 wt % RhB aqueous solutions, respectively, due to the enhanced diffusiophoretic effect, which results from the rapid photocatalytic degradation of DCIP and RhB by WO. This photocatalytic acceleration of the Au-WO@C Janus micromotors confirms the self-diffusiophoretic mechanism and opens an opportunity to tune the motility of the motors. This work also offers the light-driven micromotors a considerable potential for detection and rapid photodegradation of dye pollutants in water.

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Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.