Polarity-Sensitive fluorescent probes based on triphenylamine for fluorescence lifetime imaging of lipid droplets.

Non-alcoholic fatty liver disease (NAFLD) is a disease closely associated with metabolic abnormalities. Lipid droplets (LDs) serve as organelles that store intracellular neutral lipids and maintain cellular energy homeostasis. Their abnormalities can cause metabolic disorders and disease, which is also one of the distinctive characteristics of NAFLD patients.

Block cationic copolymer/quaternary ammonium chitosan-based composite antibacterial hydrogel dressings with NIR photothermal effects for bacteria-infected wound healing.

Wound infections caused by pathogenic bacteria can cause delayed wound healing and even threaten the life of patients. Drug resistance and effectiveness with regard to traditional wound dressings have become urgent issues which need to be addressed. The antibacterial effect of hydrogels, as novel wound dressings, is through contact-active antibacterial was limited by the contact area and time.

Alkyl chain length-regulated intelligent nano-assemblies with AIE-active photosensitizers for photodynamic cancer therapy.

Photodynamic therapy (PDT) brings new hope for the treatment of breast cancer due to few side effects and highly effective cell killing; however, the low bioavailability of traditional photosensitizers (PSs) and their dependence on oxygen severely limits their application. Aggregation-induced emission (AIE) PSs can dramatically facilitate the photosensitization effect, which can have positive impacts on tumor PDT. To-date, most AIE PSs lack tumor targeting capability and possess poor cell delivery, resulting in their use in large quantities that are harmful to healthy tissues.

Metal-organic frameworks of -hydroxybenzoic acid: synthesis, structure and ring opening polymerization capability.

Two new, isostructural, metal-organic frameworks {[Co(OCCHO)(DMF)]} and {[Mn(OCCHO)(DMF)]} have been synthesised and structurally characterized. Use of -hydroxybenzoic acid resulted in a three-dimensional MOF featuring a linker with a carboxylic group and a -hydroxyl group. Ring opening polymerization of ε-caprolactone and δ-valerolactone has been performed using these MOFs as catalysts, and results compared with the known zinc MOF Zn(OCCHO).

Enhanced Asymmetric Circularly Polarized Luminescence in Self-Organized Helical Superstructures Enabled by Macro-Chiral Liquid Crystal Quantum Dots.

Circularly polarized luminescent (CPL) materials have garnered considerable interest for a variety of advanced optical applications including 3D imaging, data encryption, and asymmetric catalysis. However, the development of high-performance CPL has been hindered by the absence of simple synthetic methods for chiral luminescent emitters that exhibit both high quantum yields and dissymmetry factors. In this study, we present an innovative approach for the synthesis of macro-chiral liquid crystal quantum dots (Ch-QDs/LC) and their CPL performance enhancement through doping with 4-cyano-4'-pentylbiphenyl (5CB), thus yielding a CPL-emitting generator (CEG).

Supramolecular assemblies derived from methyl-substituted cucurbit[5]uril and lanthanide nitrates.

Interaction of the lanthanide nitrates M(NO) (M = Gd, Eu) with methylcucurbit[5]uril (MeQ[5]) in the presence of transition metal chlorides (ZnCl and FeCl) in acidic media resulted in the isolation of the complexes [MeQ[5]Gd(HO)Cl Gd(HO)](ZnCl)∙Cl∙8.9H2O () and [MeQ[5]Eu(HO)Cl(HO)](FeCl) (). The molecular structures of  and  have been determined by single crystal X-ray crystallography, and reveal discrete complexes which are involved in dense stacking with adjacent MeQ[5]s linked via H-bonding and/or metal anions resulting in a supramolecular assembly.

Selective detection of paraquat by a cucurbit[7]uril-based fluorescent probe.

A simple fluorescent "on-off" system that can be utilized for the selective identification and determination of paraquat (PQ) is presented herein. H NMR spectroscopic data indicated that in aqueous solution the alkaloid palmatine can be partially encapsulated within the cucurbit[7]uril (Q[7]) cavity, whereby a stable 1 : 1 host-guest inclusion complex is formed. Other characterization techniques including mass spectrometry, UV-Vis and fluorescence spectroscopy also provided further evidence, and the host-guest inclusion complex was found to exhibit reasonable fluorescence intensity.

Aggregation-Induced Emission Photosensitizer with Ag(I)-π Interaction-Enhanced Reactive Oxygen Species for Eliminating Multidrug Resistant Bacteria.

Multidrug-resistant (MDR) bacteria pose serious threats to public health due to the lack of effective and biocompatible drugs to kill MDR bacteria. Photodynamic antibacterial therapy has been widely studied due to its low induction of resistance. However, photosensitizers that can efficiently generate reactive oxygen species (ROS) through both type I and type II mechanisms and that have the capability of multiple modes of action are rarely reported.

Regulable high-contrast mechanofluorochromic enhancement behaviour based on substituent effects.

Herein, a facile strategy was established to build mechanoresponsive luminogens with high sensitivity to substituents and positional effects. Even in slightly different structures, distinct optical phenomena, including fluorescence efficiency and mechano-responsive properties, were clearly present. Outstanding mechanical-induced emission enhancement (5-100 times) properties and reversibility makes for promising applications in pressure sensors and OLEDs.

Reaction of PhC(X)(COH) (X = OH, NH) with [VO(OR)] (R = Et, Pr): structure, magnetic susceptibility and ROP capability.

Reaction of [VO(OR)] (R = Et, Pr) with 2,2'-diphenylglycine afforded the alkoxide-bridged dimers {[VO(OR)(μ-OR)][PhC(NH)(CO)]}, whereas use of benzilic acid, in the presence of alkali metals, afforded 16-membered metallocycles {V(O)M(OR)[PhC(OH)(CO)]} (M = <1 Na, K). For the ring systems, magnetic susceptibility data is consistent with mixed-valence vanadium with an average oxidation state of 3.5.

Phenanthrothiophene-Triazine Star-Shaped Discotic Liquid Crystals: Synthesis, Self-Assembly, and Stimuli-Responsive Fluorescence Properties.

Lipophilic biphenylthiophene- and phenanthrothiophene-triazine compounds, BPTTn and CPTTn, respectively, were prepared by a tandem procedure involving successive Suzuki-Miyaura coupling and Scholl cyclodehydrogenation reactions. These compounds display photoluminescence in solution and in thin film state, solvatochromism with increasing solvent's polarity, as well as acidochromism and metal ion recognition stimuli-responsive fluorescence. Protonation of BPTT10 and CPTT10 by trifluoroacetic acid results in fluorescence quenching, which is reversibly restored once treated with triethylamine (ON-OFF switch).

Double-cavity cucurbiturils: synthesis, structures, properties, and applications.

Double-cavity Q[]s are relatively new members of the Q[] family and have garnered significant interest due to their distinctive structures and novel properties. While they incorporate glycoluril units, akin to their single-cavity counterparts, their geometry can best be described as resembling a figure-of-eight or a handcuff, distinguishing them from single-cavity Q[]s. Despite retaining the core molecular recognition traits of single-cavity Q[]s, these double-cavity variants introduce fascinating new attributes rooted in their distinct configurations.

Pyrene-Based Deep-Blue Fluorophores with Narrow-Band Emission.

High-efficiency narrow-band luminescent materials have attracted intense interest, resulting in their great colorimetric purity. This has led to a variety of high-tech applications in high-definition displays, spectral analysis, and biomedicine. In this study, a rigid pyrene core was employed as the molecular backbone, and four narrow-band pyrene-based blue emitters were synthesized using various synthetic methods (such as Lewis-acid catalyzed cyclization domino reactions, Pd-catalyzed coupling reactions like Suzuki-Miyaura and Sonogashira).

A Coumarin-Hemicyanine Deep Red Dye with a Large Stokes Shift for the Fluorescence Detection and Naked-Eye Recognition of Cyanide.

In this study, we synthesized a coumarin-hemicyanine-based deep red fluorescent dye that exhibits an intramolecular charge transfer (ICT). The probe had a large Stokes shift of 287 nm and a large molar absorption coefficient (ε = 7.5 × 10 L·mol·cm) and is best described as a deep red luminescent fluorescent probe with = 667 nm.

Influence of Steric Effects on the Emission Behavior of Pyrene-Based Blue Luminogens.

Pyrene-based derivatives have been widely deployed in organic luminescent materials because of their bright fluorescence, high charge carrier mobility, and facile modification. Nevertheless, the fluorescence output of conventional pyrenes is prone to quenching upon aggregation due to extensive intermolecular π-π stacking interactions. To address this issue, a set of new -shaped pyrene-containing luminogens are synthesized from a new bromopyrene chemical precursor, 2-hydroxyl-7--butyl-1,3-bromopyrene, where the bromo and hydroxyl groups at the pyrene core can be readily modified to obtain the target products and provide great flexibility in tuning the photophysical performances.

Detection of basic amino acids under highly alkaline conditions using a perylene amine-derived probe.

pH plays a crucial part in numerous chemical and physiological processes. In this work, a new perylene diimide derivative that acts as a pH-sensitive dye with Bay Area Carboxylic Acid functionality. The derivative utilizes the outstanding thermal, chemical and photochemical stability found in PDI materials and has remarkable UV-visible absorption and fluorescence emission qualities.

Double Cross-Linked Hydrogel Dressings Based on Triblock Copolymers Bearing Antifreezing, Antidrying, and Inherent Antibacterial Properties.

Bacterial infections typically invade the living tissue of wounds, thereby aggravating the inflammatory response, delaying wound healing, or causing further complications. In this paper, the antibacterial hydrogel (PNVBA) with antifreezing and antidrying properties was prepared by a two-step method using -isopropylacrylamide (NIPAM), 1-butyl-3-vinylimidazolium bromide (VBIMBr), and 3-acrylamidophenylboronic acid (AAPBA). PNVBA hydrogels exhibited a high adsorption capacity of 280 mg·g for bovine serum albumin (BSA) and can adhere to the surface of different materials through ion-dipole or hydrogen-bonding interactions.

Mixed-magnesium/zinc calix[4]arene complexes: structure, and ring opening polymerisation studies.

Different combinations of organomagnesium reagents and zinc bromide react with either 1,3-dimethoxy-4--butylcalix[4]areneH (L(OMe)H) or trialkoxycalix[4]arenes (L(OR)H) (R = -Pr, -pentyl) to afford mixed-metal calix[4]arene systems. Intriguing molecular structures are formed and the systems are capable of the ring opening polymerisation of ε-caprolactone under N, air, or as melts.

New pyrrolo[3,2-b]pyrroles with AIE characteristics for detection of dichloromethane and chloroform.

Three new pyrrolo[3,2-b]pyrrole derivatives containing methoxyphenyl, pyrene or tetraphenylethylene (TPE) units (compounds 1-3) have been designed, synthesized and fully characterized. The aggregation-induced emission (AIE) properties of compounds 1-3 were tested in different water fraction (f ) of tetrahydrofuran (THF). The pyrrolo[3,2-b]pyrrole derivative 3 containing TPE units exhibited typical AIE features with an enhanced emission (∼32-fold) in the solid state versus in solution; compounds 1 and 2 exhibited an aggregation-caused quenching effect.

A facile and sensitive hexahomotrioxacalix[3]arene-based fluorescent sensor for the detection of trace amounts of 2,4,6-trinitrophenol.

Nitroaromatic compounds are common explosives and toxic pollutants, the selective and sensitive detection of which is of great importance. Herein, a facile and sensitive fluorescent sensor L was constructed for the sensing of TNP based on the hexahomotrioxacalix[3]arene skeleton. The fluorescence emission of L was drastically quenched in the presence of 2,4,6-trinitrophenol (TNP), while other tested NACs, metal ions, and anions induced negligible changes.

Aggregation behaviour of pyrene-based luminescent materials, from molecular design and optical properties to application.

Molecular aggregates are self-assembled from multiple molecules weak intermolecular interactions, and new chemical and physical properties can emerge compared to their individual molecule. With the development of aggregate science, much research has focused on the study of the luminescence behaviour of aggregates rather than single molecules. Pyrene as a classical fluorophore has attracted great attention due to its diverse luminescence behavior depending on the solution state, molecular packing pattern as well as morphology, resulting in wide potential applications.

Pyrene-Based Cationic Fluorophores with High Affinity for BF, PF, and ClO Anions: Detection and Removal.

Anions play an indispensable role in the balance and regulation of the ecological environment and human health; however, excess anions can cause serious ecological and environment problems. Therefore, the detection and removal of excess anions in aqueous solution is not only a technological problem but also crucial for environmental protection. Herein, a set of water-soluble pyrene-based cationic fluorophores were synthesized, which exhibit high sensitivity for the detection of the anions BF, PF, and ClO via electrostatic interactions.