Exploring the growth characteristics of for controlling juice spoilage with zero additives.

Fruit juice spoilage that caused by contaminated has brought huge losses to beverage industry worldwide. Thus, it is very essential to understand the growth and metabolism processing of () in controlling juice spoilage caused by . In this work, simulative models for the growth and metabolism of were systematically conducted in the medium and fruit juice.

Self-Assembled Perylene Bisimide-Cored Trigonal Prism as an Electron-Deficient Host for C and C Driven by "Like Dissolves Like".

Poor processability of fullerenes is a major remaining drawback for them to be studied monomolecularly and to find real-life applications. One of the strategies to tackle this problem is to encapsulate them within a host, which is however quite often, accompanied by significant alteration of their physical/chemical properties as encountered in chemical modification. To minimize the effect, an electron-deficient entities-based, dissolvable, and fluorescence active supramolecular host was designed and constructed via coordination-driven self-assembly of -tetrapyridyl perylene bisimide (PBI) with -(PEt)Pt(OTf).

Fluorescence Toggling Mechanism of Photochromic Phenylhydrazones: N-N Single Bond Rotation-Assisting / Photoisomerization Differs from Imine.

Photochromic phenylhydrazones are one of the most promising candidates for a photoswitchable fluorescent probe with potential applications in various fields, but mechanistic understanding of the origin of this unique behavior is limited. In this work, we explored the emission nature and switching mechanism of a model phenylhydrazone-based fluorescent photoswitch, DMA-PHA, by means of TD-DFT and CASPT2 calculations. The fluorescence-emitting configuration of DMA-PHA does not involve an excited-state intramolecular proton transfer process since the resonance effect between the DMA group and the rest part of the molecule in the excited state strengthens the hydrogen bond and thus stabilizes the emissive state.

Perylene Bisimide and Naphthyl-Based Molecular Dyads: Hydrogen Bonds Driving Co-planarization and Anomalous Temperature-Response Fluorescence.

The origin of the positive temperature effect in fluorescence emission of a newly designed perylene bisimide (PBI) derivative with two naphthyl units containing ortho-methoxy group (NM) at its bay positions (PBI-2NM) was elucidated. A key point is the finding of a weak hydrogen bond (<5.0 kcal mol ) between the methoxy group of the NM unit and a nearby hydrogen atom of the PBI core.

Coordination-Driven Self-Assembled Metallacycles Incorporating Pyrene: Fluorescence Mutability, Tunability, and Aromatic Amine Sensing.

Constructing polycyclic aromatics-based, highly emissive fluorophores with good solubility and tunable aggregated structures and properties is of great importance for film fabrication, solution processing, and relevant functionality studies. Herein, we describe a general strategy to endow conventional organic fluorophores with enhanced solubility and modulated fluorescent properties via their incorporation into coordination-driven self-assembled metallacycles. A widely used fluorophore, pyrene, was decorated with two pyridyl groups to yield functionalized pyrene 4.

Fast, sensitive, selective and reversible fluorescence monitoring of TATP in a vapor phase.

The development of sensors for the detection of triacetone triperoxide (TATP) has attracted great attention. Here, we constructed a low-cost, portable, reusable, visible paper-based fluorescent sensor for the sensitive detection of TATP via vapor sampling. Under optimized conditions, the fluorescent film showed a high sensitivity to TATP with a detection limit of lower than 0.

Highly Sensitive and Discriminative Detection of BTEX in the Vapor Phase: A Film-Based Fluorescent Approach.

BTEX (benzene, toluene, ethylbenzene, o-xylene, m-xylene, and p-xylene) represents a group of volatile organic compounds (VOCs) and constitutes a great threat to human health. However, sensitive, selective, and speedy detection of them on-site and in the vapor phase remains a challenge for years. Herein, we report a film-based fluorescent approach and a conceptual sensor, which shows unprecedented sensitivity, speed, and reversibility to the aromatic hydrocarbons in the vapor phase.

Non-contact identification and differentiation of illicit drugs using fluorescent films.

Sensitive and rapid identification of illicit drugs in a non-contact mode remains a challenge for years. Here we report three film-based fluorescent sensors showing unprecedented sensitivity, selectivity, and response speed to the existence of six widely abused illicit drugs, including methamphetamine (MAPA), ecstasy, magu, caffeine, phenobarbital (PB), and ketamine in vapor phase. Importantly, for these drugs, the sensing can be successfully performed after 5.

Calix[4]arene-Based Dynamic Covalent Gels: Marriage of Robustness, Responsiveness, and Self-Healing.

Herein, the report on a new class of self-healing and pH/temperature responsive mixed solvent (ethanol and water) gels shows unusual mechanical properties to resist slicing, sustain high compression, and withstand stretching as evidenced by the cutting breaking stress, the fracture compressive stress, and the stretching ratio of one of the gels as obtained can reach or exceed 26.4 MPa, 9.2 MPa, and ≈5 times, respectively.

Naphthalimide-Based Fluorophore for Soft Anionic Interface Monitoring.

A naphthalimide-based low-molecular-mass fluorophore (NA) was designed and synthesized by introducing an azetidine unit onto the aromatic ring of the compound as an electron-donating structure, and a hydrophilic (2-(2-aminoethyl-amino)ethanol) moiety into the "N-imide site" of the core structure. UV-vis absorption and fluorescence measurements revealed that the fluorophore is soluble in water and shows a fluorescent quantum yield of ∼20% and lifetime of ∼3.7 ns in the solvent within a wide pH range.

Langmuir-Blodgett films of perylene bisimide derivatives and fluorescent recognition of diamines.

Fast, sensitive and selective detection of diamines in the vapor phase is of pivotal importance for air and food quality monitoring. In this work, an electron-poor fluorophore, perylene bisimide (PBI), was modified with hydrophilic residues at its bay positions, resulting in an amphiphilic derivative, PEBBO. Photophysical studies revealed that the compound shows a strong aggregation tendency in various solvents, but the aggregates could be highly fluorescent provided suitable solvents are used.

Tuning the formation of reductive species of perylene-bisimide derivatives in DMF via aggregation matter.

Host-guest interaction and chemical modification are found to be effective in tuning the formation of reductive species of perylene-bisimide (PBI) derivatives in DMF. Moreover, some of the PBI derivatives as synthesized produce radical anions in the solvent without the need of a base.

Dynamic Chemistry-Based Sensing: A Molecular System for Detection of Saccharide, Formaldehyde, and the Silver Ion.

Development of artificial complex molecular systems is of great importance in understanding complexity in natural processes and for achieving new functionalities. One of the strategies is to create them via optimized utilization of noncovalent interactions and dynamic covalent bonds. We report here on a new complex molecular system, which was constructed by integrating the multiple interactions containing a dynamic covalent interaction between 1,2-diol and boronic acid, a coordination interaction between the silver ion and pyridyl, and an easy accessible reaction between secondary amine and formaldehyde.

Can the Excited State Energy of a Pyrenyl Unit Be Directly Transferred to a Perylene Bisimide Moiety?

A pyrenyl unit (Py) was chemically connected to a perylene bisimide (PBI) moiety through a long and flexible linker, 4,7,10-trioxa-1,13-tridecanediamine (TOA), resulting in a fluorescent dyad, PBI-TOA-Py. Ultraviolet-visible absorption and fluorescence studies revealed that the two fluorescent units of PBI-TOA-Py behave independently. However, efficient Förster resonance energy transfer (FRET) from the Py unit to the PBI moiety in solution state was also observed.

Functionality-Oriented Derivatization of Naphthalene Diimide: A Molecular Gel Strategy-Based Fluorescent Film for Aniline Vapor Detection.

Modification of naphthalene diimide (NDI) resulted in a photochemically stable, fluorescent 3,4,5-tris(dodecyloxy)benzamide derivative of NDI (TDBNDI), and introduction of the long alkyl chains endowed the compound with good compatibility with commonly found organic solvents and in particular superior self-assembly in the solution state. Further studies revealed that TDBNDI forms gels with nine of the 18 solvents tested at a concentration of 2.0% (w/v), and the critical gelation concentrations of five of the eight gels are lower than 1.

A perylene bisimide derivative with pyrene and cholesterol as modifying structures: synthesis and fluorescence behavior.

A perylene bisimide (PBI) derivative (C-PBI-Py) of pyrene (Py) and cholesteryl residue (C) possessing intra-molecular energy transfer properties and three reference compounds (C-Py, C-PBI, PBI-Py) were designed and synthesized, where C was introduced in order to enhance the solubility of the relevant compounds in organic solvents. UV-vis absorption, steady-state fluorescence, cyclic voltammetric and theoretical calculation studies revealed that: (1) the PBI unit and Py moiety of C-PBI-Py could act as two individual chromophores, (2) the excited state energy of Py could transfer to PBI within a single molecule of the compound, and (3) the PBI moiety of the compound tends to form aggregates and shows PBI excimer emission. Time-resolved and temperature-dependent emission spectroscopy studies revealed the presence of both H-type excimer and J-type excimer, and formation of them via either the Birks' scheme or the pre-formed scheme due to strong π-π stacking that was elucidated by concentration-dependent (1)H NMR spectroscopy measurement.

N-acetylglucosamine-based efficient, phase-selective organogelators for oil spill remediation.

Two simple, eco-friendly and efficient phase-selective gelators were developed for instant (<45 s) gelation of oil (either commercial fuels or pure organic liquids) from an oil-water mixture at room temperature to combat marine oil spills.