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Following a reverse dissolution mechanism, aniline-based macrocyclic arenes show significant iodine uptake capacities, fast uptake kinetics and good recyclability.

Catalytic enantiodifferentiating photoisomerization of cyclooctene (1Z) included and sensitized by regioisomeric 6-O-(o-, m-, and p-methoxybenzoyl)-β-cyclodextrins (CDs) was performed under a variety of solvent conditions for higher enantioselectivities. The enantiomeric excess (ee) of chiral (E)-isomer (1E) produced was a critical function of all the internal and external factors examined, in particular, the sensitizer structure and the solvent conditions, to afford (R)-1E in record-high ee's of up to 67% upon sensitization with the meta-substituted β-CD host in water and salt solutions but neither in 50% aqueous ethanol nor with the ortho- and para-substituted hosts. The mechanistic origin of the sudden ee enhancement achieved under the specific conditions is discussed on the basis of the circular dichroism spectral behaviors upon substrate inclusion and the compensatory enthalpy-entropy relationship of the activation parameters for the enantiodifferentiating photoisomerization.

Catalytic enantiodifferentiating photoisomerization of cyclooctene (

A three-dimensional reduced graphene oxide nanomaterial with β-cyclodextrin modified glassy carbon electrode (3D-rGO/β-CD/GCE) was constructed and used to detect the electrochemical behavior of dopamine (DA). The nanocomposite materials were characterized by scanning electron microscopy (SEM), infrared spectrometry (FT-IR), Raman spectrogram and thermogravimetric analysis (TGA), which showed that β-CD was well modified on 3D graphene with a porous structure. The electrochemical properties of different modified electrodes were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), proving the highest electron transfer rate of the 3D-rGO/β-CD modified electrode. The experimental conditions such as scan rate, pH, enrichment time and layer thickness were optimized. Under the best experimental conditions, DA was detected by differential pulse voltammetry (DPV) by 3D-rGO/β-CD/GCE with excellent electrocatalytic ability and satisfactory recognition ability, resulting in a wide linear range of 0.5–100 μM and a low detection limit (LOD) of 0.013 μM. The modified electrode based on 3D-rGO/β-CD nanocomposites is promising in the field of electrochemical sensors due to its high sensitivity and other excellent properties.

A novel and facile chiral sensing platform has been designed for electrochemical enantiomer recognition based on the coupling of three-dimensional-graphene with hydroxypropyl-β-cyclodextrin (3D-G/HP-β-CD). The chiral platform synergistically exploits HP-β-CD as a supramolecular chiral recognizer and 3D-G as an electrochemical indicator, to recognize tryptophan (Trp) enantiomers by differential pulse voltammetry (DPV) approach with significantly discernable electrochemical signals. The different host–guest interactions of D- and L-Trp with HP-β-CD reveal high binding affinity to target L-tryptophan for sensing tryptophan isomers. Moreover, we found that the peak currents of the two enantiomers showed a linear response in the concentration range of 0.5–175 μM with low detection limits of 9.6 nM and 38 nM for L- and D-Trp (S/N = 3), respectively, exhibiting remarkable sensitivity, fine reproducibility as well as great stability. This process, which is the initial demonstration of cyclodextrin-functionalized 3D-G for an electrochemical chiral recognition application, provides a new strategy for enantiosensing.

Reduced graphene oxide containing Fe3O4 nanoparticles was decorated with hydroxypropyl-β-cyclodextrin (HP-β-CD) to construct a novel nanocomposite (3D-rGO/Fe3O4/HP-β-CD). The composite was placed on a glassy carbon electrode (GCE) to design an electrochemical sensor for detecting simultaneously serotonin (5-HT), dopamine (DA), and ascorbic acid (AA). The interconnected porous reduced graphene oxide framework tightly anchored to the Fe3O4 magnetic nanoparticles warrants good electrical conductivity and efficient catalytic activity. The HP-β-CD acts as a supramolecular host with high recognition ability for 5-HT, DA and AA. Well-separated oxidation peaks and increased peak currents were observed for 5-HT, DA, and AA individually and in mixtures by differential pulse voltammetry (DPV). The following figures of merit were found for simultaneous electrochemical determination of 5-HT, DA, and AA: (a) Well separated peaks at around 0.316, 0.16 and − 0.044 V; (b) linear responses in the 0.01 – 25 μM, 0.02 – 25 μM and 10 – 350 μM; (c) detection limits of 3.3 nM, 6.7 nM and 3.3 μM (S/N = 3), and (d) recoveries of 96.9-103%, 97.3%-102% and 96.3-105% from spiked serum samples, respectively. All relative standard deviation (RSD) are less than 4%.

Reduced graphene oxide containing Fe

The versatile three-dimensional magnetic sulfur/nitrogen co-doped reduced graphene oxide nanomaterials (3D-MSNGs) have been constructed and generated via interfacial coordination assembly of three-dimensional sulfur/nitrogen dual-doped reduced graphene oxide (3D-SNG) with concurrent modification by formed magnetic Fe3O4. Using ferric ions as iron source, the as-obtained nanohybrid 3D-MSNG-1 possesses abundant hierarchical porous structure on graphene network, large BET surface area and favorable magnetic properties, which is proved excellent adsorption capacity and easy magnetic separation. When 3D-MSNG-1 was utilized to absorb the dyes of methylene blue (MB), congo red (CR) and neutral red (NR) considered as cationic, anionic and neutral model dye molecules, respectively, the adsorption equilibrium for MB, CR and NR were rapidly achieved in 15 min. The adsorption isotherm fits Langmuir adsorption model well with the maximum uptake capacity for MB, CR and NR high to 171.53 mg/g, 909.09 mg/g and 877.19 mg/g, respectively. Meanwhile, an efficacious treatment of ternary dyes mixed solution and a good recyclability manifests that 3D-MSNG-1 is supposed to be a superior adsorbent in the areas of water treatment.