Rigid Enhanced Electrochemiluminescence of 1,2,3-Triaryl Indenes as an Ultrasensitive Sensor for D₂O in H₂O

The intriguing aggregation-induced emission has recently been applied in the electrochemiluminescence, called aggregation-induced electrochemiluminescence (AIE-ECL), which is conducive to solving the water insolubility and aggregation-caused quenching for most organic luminescence probes. However, AIE-ECL still has the problems of low luminous efficiency and limited practical application. In this work, we disclosed the AIE-ECL properties of 1,2,3-triaryl-substituted indenes containing rigid structures. Experimental and theoretical investigations demonstrated that such a rigid structure could significantly enhance the aromaticity and stability and thereby the luminescence performance of these indenes. Moreover, according to the finding of hydrogen/deuterium exchange for active hydrogen in indene under electrical excitation, ultrasensitive detection for D2O in H2O was realized by such an indene-based AIE-ECL system. Our research not only provided an attractive strategy to enhance the luminescence property for an AIE-active luminophore but also established a superior sensor toward D2O

Unraveling the Ligand-Binding Sites of CYP3A4 by Molecular Dynamics Simulations with Solvent Probes

Cytochrome P450 3A4 (CYP3A4) is one of the most important drug-metabolizing enzymes in the human body and is well known for its complicated, atypical kinetic characteristics. The existence of multiple ligand-binding sites in CYP3A4 has been widely recognized as being capable of interfering with the active pocket through allosteric effects. The identification of ligand-binding sites other than the canonical active site above the heme is especially important for understanding the atypical kinetic characteristics of CYP3A4 and the intriguing association between the ligand and the receptor. In this study, we first employed mixed-solvent molecular dynamics (MixMD) simulations coupled with the online computational predictive tools to explore potential ligand-binding sites in CYP3A4. The MixMD approach demonstrates better performance in dealing with the receptor flexibility compared with other computational tools. From the sites identified by MixMD, we then picked out multiple sites for further exploration using ensemble docking and conventional molecular dynamics (cMD) simulations. Our results indicate that three extra sites are suitable for ligand binding in CYP3A4, including one experimentally confirmed site and two novel sites

Confinement Effects in Carbonized ZIF-Confined Hollow PtCo Nanospheres Enable the Methanol Oxidation Reaction

Confinement effects in highly porous nanostructures can effectively adjust the selectivity and kinetics of electrochemical reactions, which can boost the methanol oxidation reaction (MOR). In this work, carbonized ZIF-8-confined hollow PtCo nanospheres (PtCo@carbonized ZIF-8) were fabricated using a facile strategy. A monodisperse confined region was successfully prepared, and the dispersion of the PtCo nanoparticles (NPs) could be precisely regulated, allowing for the effective tuning of the confined region. Thus, the precise regulation of the catalytic reaction was achieved. Importantly, hollow PtCo NPs were prepared using a method based on the Kirkendall effect, and their forming mechanism was systematically investigated. Because of the confinement effects of carbonized zeolitic imidazolate framework-8 (ZIF-8), the crystal and electronic structures of the PtCo NPs were able to be effectively tuned. Our electrochemical results show that PtCo@carbonized ZIF-8 composites manifest a higher mass activity (1.4 A mgPt–1) and better stability compared to commercial Pt/C