Explosive developments in modern society bring huge fire loads. Previous fire detections at early stages are basically enabled by recognizing abnormal high-temperatures, smoke particles, and flame light signals. However, the identification of these characteristic signals is generally accompanied by an open flame or smoke, which makes it difficult to prevent further serious damage. Herein, a latent-firedetecting strategy of trace ammonia (NH 3 ) analysis based on nanohybrid Ti 3 C 2 T x MXene/MoS 2 is proposed. Benefiting from nanoscale high-density Schottky heterojunctions between MoS 2 and Ti 3 C 2 T x MXene, ultrafast (3 s @100 ppm), sub-ppm (200 ppb minimum), and high-sensitivity (81.7% @100 ppm and 10.2% @200 ppb) detection of NH 3 are enabled. An assembled latent-fire-detecting olfactory system (LFOS) based on MXene/MoS 2 and interdigital electrodes can monitor trace NH 3 releases from different materials (wool, leather, foam, and nylon) during thermal decomposition at latent stages. Notably, the LFOS can detect fire threats at least 84 s earlier than commercialized smoke detectors, providing more fire dealing time and an escape period; this offers a promising latent-fire-warning approach for eliminating fire treats at an early stage.

Adhesive polysaccharide gels have highlighted their potential in biomedicine, tissue engineering, and wearable/implantable devices due to their tissue adhesive nature and excellent biocompatibility.

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Photonic materials that enable visual detection of chemicals have shown great potential for wide applications in chemical, environmental, biotechnological, and food industries, but until now, using hydrophilic photonic materials for tracing watersoluble chemicals remains a major challenge due to the strong water interference. Here, we demonstrate a two-step co-assembly and subsequent surface coating strategy to develop an ethanolsensitive and anti-water interference photonic crystal film. By using citric acid as a co-assembly phase, high ethanol sensing is realized because of the strong intermolecular affinity. By controlling the thickness of the outer polyvinyl butyral layer, selective ethanol penetration but a water barrier is enabled. Notably, the composite photonic films are free-standing, highly flexible, and controllably structurally colored. We further present using the composite film to quantitatively trace ethanol/water mixtures and potentially track drunk driving as a colorimetric sensor. The heuristic two-step modification strategy proposed in this work not only overcomes the limitation of water interference for hydrophilic colorimetric sensors but also provides references to develop more new photonic materials with water resistance that need to be applied in water/humid environments.

The continuation of human civilization has always been accompanied by symbiosis and confrontation with fire. Particularly, humans can comprehensively recognize fire situations based on various sensory receptors in organs (eyes, skin, nose, etc.), further forming a sound fire perception system by in‐the‐brain recording, modeling, and understanding fire behaviors, leading to the most accurate fire treatments. If a sensing perception system can mimic human perceptual behavior and carry out real‐time fire recognition, such an active defense system can achieve real fire safety. Here, inspired by the brain‐centered perception system, an early‐fire perception system enabled by a VO2‐based temperature‐flame‐modulated optical switch, and a machine‐learning‐assistant demodulation algorithm is reported. This approach creates real‐time monitoring composed of early fire warning (1 s for candle flame and 4 s for 130 °C heat flow), fire cause recognition (95.7% accuracy in identification), and evacuation advice provision, advancing the technologies in the perception system that enable future sensors the comprehensive perception capability for fire state.

Platelet-rich plasma (PRP), a platelet-rich plasma concentrate obtained from whole blood, has been widely used to treat wounds due to its high contents of growth factors that can not only play a role in the hemostasis, repair, and anti-infection of wounds but also promote cell proliferation, maturation, and angiogenesis. However, after PRP activation, its clinical effect was limited because of burst and uncontrolled release of growth factors and poor mechanical properties of PRP gels. In recent years, increasing attention has been moved to the loading and sustained release of growth factors in PRP by polymeric carriers. Hydrogels, as an interesting carrier, enable controlled delivery of growth factors by structural designs. Moreover, using hydrogels to encapsulate PRP is favorable to controlling the mechanical properties and water maintenance of PRP gels, which can provide a stable and moist wound repair environment to promote coordinated operations of skin tissue cells and cytokines as well as wound healing. In this review, the state of the art of hydrogels that have been used to load PRP for wound treatments is introduced, and further prospects in the research area are proposed.