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A supramolecular polymer was developed through the encapsulation of polypyrrole by cucurbit[6]uril (PPy@Q[6]), which was employed as the electrode material to improve the capacitor ability of conductive polypyrrole.

An innovative photoanode was developed for efficient PEC water splitting by the deposition of a Co nano-catalyst on the surface of a g-C3N4 film, producing the significant photocurrent density of 393 μA cm−2 at 1.23 V vs. RHE.

A supramolecular strategy was developed for electrocatalytic water splitting in the presence of a macrocyclic compound. The improvement in the oxygen evolution reaction (OER) was observed on the surface of an electrode modified via the facile layer-by-layer assembly of polypyrrole (PPy), reduced graphene oxide (rGO) and cucurbit[6]uril (Q[6]) in sequence. The electrochemical performance was evaluated, and the results indicate the remarkable activity of the proposed supramolecular electrocatalyst toward the OER in alkaline media. The morphology and chemical structure of the electrocatalyst were estimated before and after the OER process. Linear sweep voltammetry measurements suggested that a current density of 10 mA cm−2 at an overpotential of 377 mV was achieved, which is very close to the value of IrO2 under the same conditions, and the calculated Tafel slope of 167 mV dec−1 and electrochemical impedance spectroscopy results imply that a fast charge transfer occurs on the electrode with the functionalization of Q[6]. The developed catalyst could be considered as a potential alternative material for high-efficiency electrocatalytic OER.

A supramolecular polymer was developed through the encapsulation of polypyrrole by cucurbit[6]uril (PPy@Q[6]), which was employed as the electrode material to improve the capacitor ability of conductive polypyrrole. In the optimized ratio of 2 : 1 (

An electrochemiluminescence (ECL) sensor based on a benzo[3]uril-modified glassy carbon electrode with sensitized luminescence, with the coexistence of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) as the coreactant, was successfully constructed. The sensitization mechanism was proposed by analyzing the results of the control experiments for establishing the relationship of the luminescence effect with the concentration of HEPES. Under the optimized conditions, the fabricated sensor system was applied for the detection of Fe3+ in an aqueous solution with good sensitivity and selectivity. A low detection limit of 0.41 nM was achieved, indicating superior sensor performance over the previous analytical methods. The ECL sensor system was employed for the detection of Fe3+ in human serum samples to produce excellent recoveries ranging from 96.17% to 101.81%.

An electrochemiluminescence (ECL) sensor based on a benzo[3]uril-modified glassy carbon electrode with sensitized luminescence, with the coexistence of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) as the coreactant, was successfully constructed. The sensitization mechanism was proposed by analyzing the results of the control experiments for establishing the relationship of the luminescence effect with the concentration of HEPES. Under the optimized conditions, the fabricated sensor system was applied for the detection of Fe

A selective and sensitive fluorescent chemosensor based on an anthracene-functionalized triazole-linked multifarene[2,2] was successfully synthesized and investigated with regard to the recognition of metal ions using fluorescence spectroscopy, 1H NMR titration, and IR spectroscopy. The proposed sensor exhibited desirable properties for potential fluorescence enhanced chemosensor applications, including selective affinity and low Zn2+ and Cd2+ detection limits compared with other metal ions. Quantum chemical calculations described the synthesized chemosensor's static structure and its coordination to Zn2+ and Cd2+. Frontier molecular orbital distribution and energy changes suggested a possible mechanism for increased receptor fluorescence intensity with Zn2+ and Cd2+ addition.

The supramolecular interaction between hemicucurbit[6]uril (HemiQ[6]) and ferrocene is investigated using 1 H and 13 C NMR spectroscopy, cyclic voltammetry (CV), isothermal titration calorimetry (ITC) and quantum chemistry. By means of the 1 H NMR and 13 C NMR spectra, the host-guest interaction is confirmed by the slight shift in the resonance peaks of ferrocene. Cyclic voltammetry shows the diffusion current of ferrocene was enhanced with a slight improvement in the voltammetric behavior in the presence of HemiQ[6]. Isothermal titration calorimetry provides thermodynamic data for the host-guest interaction and an association constant of K a = 4.9 × 10 4 L mol −1 in a 1:1 ratio has been obtained. Quantum chemistry suggests the encapsulation complex was stabilized by the formation of hydrogen bonding between the aromatic protons on the ferrocene guest molecule and the carbonyl groups on hemicucurbit[6]uril, and the electron transfer of the interaction complex is more easy than in free ferrocene.

The host–guest interaction between tetramethylcucurbit[6]uril (TMeQ[6]) and 2-(4-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline hydrochloride salt (guest 1) has been investigated. 1H NMR results have confirmed the formation of an encapsulated complex, and fluorescence titration implies an interaction ratio of 1:1 with a moderate association constant of Ka = 4.0 × 106 L mol−1. The triggered fluorescence emission of guest 1 by TMeQ[6] has been developed to achieve a supramolecular probe capable of recognizing La3+ and Ce3+ through a dramatic decrease in fluorescence intensity, whereas there is minimal difference upon the introduction of Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Er3+, or Tm3+. Combined evidence from 1H NMR, IR, and fluorescence titration supports coordination of the inclusion complex to La3+ and Ce3+, with association constants of 1.1 × 104 L mol−1 and 1.0 × 104 L mol−1, respectively. The linear decrease in fluorescence intensity in response to different concentrations of La3+ or Ce3+ gives a low limit of detection (LOD) of 1.1 × 10−8 mol L−1.

The host–guest interactions of hemicucurbit[6 and 12]urils with the Schiff base guest 1 has been investigated. 1H NMR spectra suggest hemicucurbit[6 and 12]urils bind to guest 1 with the formation of hydrogen bondings between the phenol hydroxyl group and carbonyl groups in the host. The formation of interaction complexes are also supported by fluorescence emission spectroscopy. The moderate association constants of the interaction complexes in a ratio of 1:1 are obtained to be (3.2 ± 0.6) × 105 and (5.5 ± 0.8) × 105 L mol−1, respectively, via non-linear curve fitting, which indicate that the formation of hydrogen bondings are important in the host–guest interactions.

The host–guest interactions between hemicucurbit[6 and 12]urils and o-, m-, and p-aminophenols have been investigated by means of 1H NMR spectrometry, fluorescence emission spectroscopy, and isothermal titration calorimetry. The 1H NMR spectra suggest that the interaction could involve hydrogen bonding between the hydroxyl groups of the guests and the carbonyl groups of the hemicucurbiturils. The fluorescence emissions of the guests are enhanced upon addition of increasing amounts of hemicucurbiturils, with a slight blue-shift of the emission peaks. Moreover, the linearity of emission intensity responses of the guests to the HemiQs concentration shows different slopes depending on the structure of the hemicucurbituril. Thermodynamic data have been obtained by isothermal titration calorimetry, and the results indicate 1:1 host–guest interactions between the hemicucurbiturils and aminophenols. All of the interaction systems have similar stabilities and approximately equal association constants, and the negative enthalpy change upon the addition of the hemicucurbiturils is the driving force of the host–guest interaction. Formation of interaction complexes of aminophenols with hemicucurbit[6 and 12] in organic solvent have been investigated.