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Binding of a synthesized fluorescent probe to latent fingerprints results in the aggregation-induced emission of green light, which is better perceived by the human eye than other colors and provides up to three levels of minutiae characteristics of latent fingerprints.

Supramolecular hydrogels attract extensive attention as waterborne biocompatible materials like biological tissues. Here we developed poly[N-(2-acetamidoethyl)acrylamide] (PAAE) supramolecular hydrogels with multiple hydrogen bonds, which exhibit ideal mechanical performances, such as strong resistance to compression and stretch, high stability in acidic or high ionic strength solution, excellent waterborne adhesiveness, self-healing and swelling behaviors. The small molecular precursor for PAAE hydrogels possesses great solubility up to 70 wt% in deionized water and superior infiltration capability to mouse brain tissues at 5 °C, and can be in situ polymerized at 30–45 °C and swollen in deionized water with a 1.75 times linear expansion factor. There is no noticeable loss of fluorescence intensity during the whole process from small molecular infiltration and polymerization to expansion. The mouse brain slices were embedded and used for expansion microscopy with enhanced optical resolution and preserved structure integrity.

Bi2Se3 is a promising anode material for lithium-ion batteries (LIBs) due to its high capacity and weak van der Waals stacking for Li-ion insertion. However, it suffers from low conductivity and structural instability during the Li-ion insertion and extraction processes. Herein, a new carbon nanofiber (CNF) network decorated with Bi2Se3 nanoparticles (∼40 nm) was facilely prepared and directly used as a binder-free flexible anode in LIBs. The Bi2Se3/CNFs anode delivered a high reversible gravimetric capacity of 443 mA h g−1 after 260 cycles at 100 mA g−1 and a rate capability of 103 mA h g−1 at 16 A g−1. The full cell with LiCoO2 vs. Bi2Se3/CNFs has a discharge specific capacity of 261 mA h g−1 after 100 cycles at 100 mA g−1. The excellent Li-storage performance is attributed to the Bi2Se3 nanoparticles uniformly embedded in the unique conductive 3D CNFs network which effectively improves the conductivity and avoids the layer structure collapse of Bi2Se3 materials. The synergistic effect of the enhanced characteristics successfully improved the long-term cycling and rate capability of the Bi2Se3 anode. This flexible and binder-free Bi2Se3/CNFs electrode has great potential as a neoteric anode material for LIBs.

Smart materials based on photo-responsive dynamic covalent bonds have the potential for use in many applications, such as photo-modulated manipulators, actuators and self-healing materials. However, the development of high-performance multifunction visible-light-driven dynamic covalent systems has been insufficient. Herein, we report a novel linear polyurethane elastomer (HABI-PU) containing visible-light-switchable hexaarylbiimidazole (HABI) units in the polymer backbone with photo-induced scission and rapid healing capacities. When exposed to 405 nm light, the scratches on the HABI-PU film took only a few seconds to heal. More serious cut damage could be healed after exposure for 30 s and placed in the dark at room temperature for 6 h. Moreover, when a certain weight was loaded during light irradiation, the elastomers broke off as the toughness of the HABI-PU elastomers decreased. The reversible dissociation of the C–N bond of the HABI units caused the scission of long polymer chains into short chains upon light irradiation and further endowed HABI-PU with the properties of photo-induced fracture/healing. Such elastomers are promising for application in the fields of photo-controlled triggers, biomimetic systems, recycled materials, optical machining, and other engineering streams.

Fluorescence microscopy is an intuitive detection method of β-amyloid (Aβ) fibrillation, which usually occurs in early-stage Alzheimer's disease. With the aid of single-molecular localization of reversibly-activated fluorogens, the limit of optical diffraction in fluorescence microscopy can be overcome and the imaging resolution can be promoted to the sub-100 nm boundary. Aggregation-induced emission (AIE) is the fluorogenic emission behavior in which fluorescence is significantly enhanced due to the restriction of intramolecular motion when the fluorogens aggregate together or bind with specific targets. Reversible binding events of AIE-active fluorogens cause fluorescence switching enabling single-molecular localization and super-resolution imaging. Here, we report a series of super-resolution fluorescent probes with AIE activity, which are used for the detection and super-resolution imaging of fibrillar amyloids. The AIE-active fluorogens show superior in vitro sensitivity to fibrillar amyloids of hen egg white lysozyme (HEWL), which is usually used as a model protein for amyloid studies, with the limit of detection down to 63.71 nM. The fluorescence colocalization imaging indicates the excellent ex vivo targeting capability of Aβ plaques in mouse brain slices, with the colocalization degrees more than 90%. Based on the reversible binding between AIE-fluorogens and Aβ fibrils, the AIE-based super-resolution imaging of in vitro Aβ fibrillation in tubes and ex vivo Aβ plaques in mouse brain slices is accomplished. The detailed structure information reveals that Aβ plaques in the mouse brain are composed of numerous radiant nanofibrils with an optical imaging resolution of about 30 nm.

Two solvatochromic fluorenone-tetraphenylethene luminogens, 2-(4-(1,2,2-triphenylvinyl)phenyl)-9H-fluoren-9-one (TPE-FO) and 2,7-bis(4-(1,2,2-triphenylvinyl)phenyl)-9H-fluoren-9-one (TPE-FO-TPE), have been designed and synthesized, in which tetraphenylethene offers dual functions, i.e., aggregation-induced emission (AIE) and electron donation. Both TPE-FO and TPE-FO-TPE exhibit pronounced solvatochromic effects and AIEE activity. The two luminogens exhibit ultra-high sensitivity to trace water in organic solvents such as THF or dioxane. The Stern–Volmer plots show good linear relationships with water fractions below 0.9%. The detection limit of TPE-FO for water in THF is calculated to be 11 ppm which is pretty close to that of Karl–Fischer titration.

A flexible binder-free film composed of bismuth oxide nanoparticles embedded in carbon nanofibers (Bi2O3/C) was prepared by a feasible electrospinning method and directly used as a sodium ion battery (SIB) anode. As a binder-free and flexible anode for SIBs, Bi2O3/C delivers a high reversible capacity of 430 mA h g−1 after 200 cycles at a current density of 100 mA g−1 and an exceptional rate capability of 230 mA h g−1 at 3200 mA g−1. It has a stable capacity of 252 mA h g−1 after 50 cycles at 400 mA g−1 in a Na-ion full cell device. The high capacity, good cyclability and rate capability are attributed to synergistic effects of the uniform distribution of ultra-small Bi2O3 nanoparticles (≈10 nm) in the carbon nanofibers and the conducting framework of 3-D interconnected carbon nanofibers, which can effectively alleviate the volume expansion during sodiation/desodiation processes and maintain the high electrical conductivity throughout the electrode. This self-standing flexible Bi2O3/C nanocomposite electrode may hold great promise for high-performance SIBs.