Z-scheme structure SnS2–Au–CdS with excellent photocatalytic performance for simultaneous removal of Cr(VI) and methyl orange

Research on Chemical Intermediates - A highly efficient Z-scheme photocatalyst SnS2–Au–CdS was fabricated by photoreduction and thiourea medium deposition methods. It was found that Au...     

Application of Cationic Gemini Surfactant 12-3-12 and Methylene Blue in Simple Detection of DNA and Investigation of Interaction Mechanism

The present work aims to propose a new simple assay for deoxyribonucleic acids (DNA) by applying cationic Gemini surfactant 12-3-12 and cationic dye methylene blue (MB) as resonance light scattering (RLS) probes. The formation of MB-DNA-12-3-12 complex at pH 3.99 results in enhanced RLS signals at 369 nm, which is proportional to the concentration of DNA from 0 to 0.88 mg L^?1, with determination limit of 0.014 mg L^?1. Most foreign substances do not interfere in the detection and three synthetic samples are analyzed satisfactorily. transmission electron microscopy (TEM), FTIR, and ultraviolet spectra are used to investigate the interaction mechanism.     

Study of Characterization and Application on the Binding of Photochromic PAzoM26-b-PAA296 Diblock Copolymer with Bovine Serum Albumin by Spectroscopic Techniques

We have reported the synthesis and characterization of amphiphilic diblock copolymer {2-[4-(4-methoxy phenyl azo) phenoxy] hexyl acrylate co-acrylic acid} (PAzoM₂₆-b-PAA₂₉₆) and investigated the binding of this copolymer to bovine serum albumin (BSA) by TEM, ultraviolet-visible (UV-vis) absorption spectra, spectrofluorimetry, and synchronous fluorescence spectra techniques. The copolymer is photochromic and can self-assemble to form microspheres or vesicles, which could be potentially utilized in drug delivery system and the separation and purification of protein. We first present the inherent binding information using the fluorescence quenching technique, such as the quenching mechanism, binding constants, number of binding sites, thermodynamic parameters, and interaction driven forces. The binding distance and energy transfer efficiency were obtained based on Forster nonradiation energy transfer theory.     

Positive solutions of impulsive boundary value problems for first-order nonlinear functional differential equations

In this paper, we study the problem on the existence of positive solutions for a class of impulsive periodic boundary value problems of first-order nonlinear functional differential equations. By using the fixed point theorem in cones and some analysis techniques, we present some sufficient conditions which guarantee the existence of one and multiple positive solutions for the impulsive periodic boundary value problems. Our results generalize and improve some previous results. Moreover, our results show that positive solutions for the impulsive periodic boundary value problems may be yielded completely by some proper impulsive conditions (see Example 4.1 and Remark 4.2 in Sect. 4), and also implies that proper impulsive conditions are of great significance to simulate processes, optimal control, population model and so on.     

Rapid extraction of bioactive compounds from gardenia fruit using new and recyclable deep eutectic solvents

The utilization of deep eutectic solvent as an alternative and environmentally friendly option has gained significant attention. This study first proposed a series of benzylammonium chloride based-deep eutectic systems for the extraction of bioactive compounds from Gardenia jasminoides Ellis. Through the implementation of response surface methodology, the optimal solvent was determined to be dodecyldimethylbenzylammonium chloride–levulinic acid (1:3, mol/mol) with 35% (v/v) water, specifically tailored to extract geniposide, genipin-1-β-d -gentiobioside, crocin-1, and crocin-2 from gardenia fruits with the ratio of solid to liquid of 1:20 at 86°C for 16 min. Their total extraction yields could reach 70.6 mg/g, outperforming those obtained by other solvents and corresponding techniques. Furthermore, the eutectic system was retrieved after first-cycle extraction, and then applied in the subsequent extraction progress, yielding a consistent extraction efficiency of 97.1%. As compared to previous traditional methods, a quick, high-yielding, and green extraction procedure was achieved through simple heating settings that did not constrain the instrument. Therefore, dodecyldimethylbenzylammonium chloride–levulinic acid could serve as a sustainable and reusable solvent for efficient extraction of natural bioactive compounds from plant-based raw materials. The application of deep eutectic solvents has demonstrated their potential as designable solvents with stronger extraction capabilities than traditional organic solvents.     

A countercurrent chromatography solvent system based on deep eutectic solvents for separation of cis- and trans-crocetin from Gardenia jasminoides Ellis

Due to the structural similarity and large difference in concentration, the separation of trans- and cis-crocetin has been challenging, and the cis-crocetin is usually neglected. In this work, a countercurrent chromatography method was developed for the quick separation of trans-crocetin and cis-crocetin from the hydrolytic extract of Gardenia jasminoides Ellis. High purity of trans-crocetin (>95%) and cis-crocetin (>91%) were prepared simultaneously for the first time through a novel biphasic system based on deep eutectic solvents, n-heptane/n-butyl alcohol/13 mmol/L Na₂CO₃ in water/acetamide-benzyltrimethylammonium chloride (4:1, mol/mol) (4:7:9:1, v/v). The addition of deep eutectic solvent significantly improved the separation efficiency. The two targets can be easily recovered from the separation system through simple acidification and precipitation. It has potential for preparative separations on a large scale.