Syntheses of two diamine substituted 1,3-distal calix[4]arene-based magnetite nanoparticles for extraction of dichromate, arsenate and uranyl ions

The first study about the relationship between the extractability of thiacalix[4]arene derivatives and the position of the coordination binding sites

Three organic ionophores (2-4) based on the p-tert-butylthiacalix[4]arene backbone, blocked in the 1,3-alternate conformation, bearing two pyridyl coordinating moieties (ortho for 2, meta for 3 and para for 4), have been synthesized and characterized in the solid state. The solvent extraction experiments with the metal ions showed that the ability of these derivatives to complex with Ag(+) appeared to be largely dependent on the position of the nitrogen atoms of the pyridyl ring. Two different complexation modes have been confirmed by 1H NMR titration. Ionophore 2 armed with two pyridyl moieties, complexed with Ag(+) cation through N···Ag(+)···S interactions; however, ionophore 3 and ionophore 4 complexed with Ag(+) through metal-nitrogen (N···Ag(+)) interactions. The DFT computational studies were consistent with the experimental findings. These findings will provide us with an important rule to design an appropriate thiacalix[4]arene ionophore in the future. Another study on the possibility for application of ionophores 2-4 for the treatment of waste water containing Cr(VI) and Cr(III), showed that ionophore 3 was useful in the application of the solvent extraction method in selective treatment of waste water containing Cr(VI) and Cr(III) prior to discharge.

Synthesis and evaluation of a novel ionophore based on a thiacalix[4]arene derivative bearing imidazole units

Alkali metal salts play an important role in the conformer distribution of thiacalix[4]areneviaa template effect.

Enzyme immobilization in biosensor constructions: self-assembled monolayers of calixarenes containing thiols

Herein, an amperometric glucose oxidase (GOx) biosensor is presented using calixarenes as an immobilization matrix of the biomolecule.

Synergistically enhanced electrochemical response of host-guest recognition based on ternary nanocomposites: reduced graphene oxide-amphiphilic pillar[5]arene-gold nanoparticles

An amphiphilic pillar[5]arene (AP5) was modified onto the surface of reduced graphene oxide (RGO) to form the water-dispersive RGO-AP5 nanocomposite. And then, as-prepared gold nanoparticles (AuNPs) self-assembled onto the surface of RGO-AP5 through amido groups of AP5 to achieve RGO-AP5-AuNPs nanocomposites. It was verified that a large amount of AP5 molecules had been effectively loaded onto the surface of RGO and lots of AuNPs could be uniformly dispersed on RGO-AP5. Electrochemical results showed that the RGO-AP5 could exhibit selective supramolecular recognition and enrichment capability toward guest molecules. More significantly, in electrochemical sensing the guest molecules, ternary nanocomposites RGO-AP5-AuNPs performed the synergetic action of multifunctional properties, which were excellent performances of RGO, selective supramolecular recognition, and enrichment capability of AP5 and catalytic property of AuNPs for guest molecules. Therefore, RGO-AP5-AuNPs showed an outstanding analyzing performance for DA with broad linear range (1.5 × 10(-8) to 1.9×10(-5) M) and low detection limit (1.2 × 10(-8) M) at a signal-to-noise ratio of 3.

Calix[4,6,8]arenesulfonates functionalized reduced graphene oxide with high supramolecular recognition capability: fabrication and application for enhanced host-guest electrochemical recognition

Reduced graphene oxide (rGO) modified with three kinds of water-soluble p-sulfonated calix[4,6,8]arene sodium (SCn: SC4, SC6, SC8) were successfully prepared by using a simple wet chemical strategy. Three obtained SCn-rGO nanocomposites were characterized by Fourier transform infrared spectroscopy, Ultraviolet-visible spectroscopy, static contact angle measurement, thermogravimetric analysis, scanning electron microscope and electrochemical impedance spectroscopy, which confirmed that different amount of SCn molecules had been effectively loaded onto the surface of rGO, and the water-dispersity and stability of SCn-rGO increased with the increase of the value of n in SCn (n = 4, 6, 8). More significantly, cyclic voltammetry measurement showed that the SCn-rGO could exhibit high supramolecular recognition and enrichment capability and consequently displayed excellent electrochemical response toward four probe molecules (biological and organic dye molecules). Especially, SC8-rGO exhibited an excellent electrochemical performance for dopamine with high current densities of 73.04 mA mM(-1) L cm(-2), broad linear range (1 × 10(-8) to 2.1 × 10(-5) M) and very low detection limit (8 × 10(-9) M) at a signal-to-noise ratio of 3.