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A novel AIEgen molecular probe (N-3QL) with typical AIE effects, good biocompatibility, lysosome targeting, pH activation, excellent photostability, and high brightness was synthesized using two simple synthetic steps. Spectroscopic and cytotoxicity experiments indicate that N-3QL can not only be used for the dynamic monitoring of cancer cell lysosomes, but also for photodynamic therapy (PDT) ablation of cancer cells. [ABSTRACT FROM AUTHOR]

Catalytic conversion of CO2 to produce fuels and chemicals is of great importance, and the electrocatalytic CO2 reduction reaction (eCO2RR) is considered one of the most attractive pathways. Multi-carbon (C2+) products are more desirable in many cases. To date, Cu-based catalysts, especially Cu+ sites, have been found to be the most efficient for the production of C2+ products. However, the retention of Cu+ sites at high cathodic potentials in the eCO2RR remains a great challenge. In this study, we designed and synthesized CuAl-oxide-derived (CuxAly-OD, x and y are the mass percentages of Cu and Al) catalysts for the eCO2RR to C2+ products. During the eCO2RR process, the predominant Cu species changed to Cu+, and the resulting electrocatalyst showed a high faradaic efficiency (FE) of 81.6% for C2+ products in alkaline aqueous solutions. Experimental studies showed that the presence of a stable amorphous Al2O3 phase stabilized the Cu+ sites by oxidation state control, leading to high selectivity and activity for the production of C2+ products. This work provides a strategy for improving the stability of Cu+ in the catalyst to enhance the performance of the eCO2RR. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion hybrid supercapacitors (ZHSs) are promising energy storage devices owing to their high energy and power density. However, the selection of the voltage window to achieve the balance between energy density and cycling stability is still difficult. Herein, the protective effect of by-products deposited on the surface structure of the cathode material was studied based on the differences in the cycling stability of ultrathin carbon materials (UTCs) at different voltage windows. Through the calculation of the Gibbs free energy of the hydrogen evolution reaction (HER) process, the association of cathode by-products with voltage windows was described and confirmed for the first time: whether the by-product layer on the surface of the cathode material is broken or not can be considered a criterion for selecting the voltage window. Based on this, a flat pouch cell was fabricated in a wide voltage window of 0–1.9 V and exhibited an extremely high energy density of 267.9 W h kg−1 coupled with good flexibility and long cycle life with a capacity retention of 90.0% after 3000 cycles. Overall, this work introduces the relationship between cathode by-products and voltage windows for the first time, useful for providing more specific criteria for the selection of voltage windows. [ABSTRACT FROM AUTHOR]

High-entropy perovskite fluorides are very promising for the electrocatalytic oxygen evolution reaction (OER). However, the low kinetics of reconstruction reactions restrict their high catalytic activity. Herein, a novel strategy was developed for the modification of the surface K(CoMnFeNiCr)F3 (HEPF) using the electron-donating group pyrrolidone, for the first time, to promote the rate of reconstruction reactions. The experimental results and theoretical calculations demonstrated that after HEPF modification, the energy barrier for OH− adsorption was reduced to −5.37 eV. The surface modification with HEPF also enhanced the intrinsic conductivity owing to the improved band structure. This resulted in the formation of highly active catalytic species at lower potentials, leading to superior intrinsic catalytic activity. The optimized electrocatalyst exhibited an overpotential of only 242 mV at 10 mA cm−2, representing the best-reported value among similar materials. Overall, the proposed strategy looks promising for unlocking the excellent catalytic activity of high-entropy perovskite fluorides, useful for future syntheses of OER catalysts. [ABSTRACT FROM AUTHOR]

Here we report a simple and nonradioactive biochemical assay which is capable of accurately determining the substrate methylation sites of human RNA N6-methyladenosine methyltransferases METTL3/METTL14 and METTL16. This method employs enzyme-assisted chemical labelling of a specific base in an RNA substrate with the assistance of an allyl-substituted methyltransferase cofactor, and enables precise identification of the labelling site by a mutation signal from standard nucleic acid sequencing. Our method provides a platform to investigate the enzymatic methylations of long and structurally complex RNA substrates, and facilitates the discovery of new methyltransferases. [ABSTRACT FROM AUTHOR]

In the present study, a novel ratiometric SERS nanosensor via the assembly of 4-mercaptophenylboronic ester on the surface of gold nanorods has been developed and successfully applied in H2O2 imaging in living cells or cancer tissues. [ABSTRACT FROM AUTHOR]

A novel silver nanoparticle (AgNP)/DNA-two-photon dye (TP dye) conjugate was fabricated as a two-photon nanoprobe for biothiol imaging in live cells. DNA-templated silver nanoparticles are efficient quenchers and also provide a biocompatible nanoplatform for facile delivery of DNA into living cells. In the presence of biothiols (Cys, Hcy, or GSH), the strong interaction between the thiol group and silver results in the release of TP dye-labeled single-stranded DNA (ssDNA) from the AgNP surface and the subsequent fluorescence emission of the TP dye, thus enabling biothiols to be assayed. Our results reveal that the AgNP/DNA-TP dye nanosensing conjugate not only is a robust, sensitive, and selective sensor for quantitative detection of biothiols in the complex biological environment but also can be efficiently delivered into live cells and act as a “signal-on” sensor for specific, high-contrast imaging of target biomolecules. Our design provides a methodology for the development of future DNA-templated silver nanoparticle-based two-photon fluorescent probes for use in vitro or in vivo as biomolecular sensors for live-cell imaging. [ABSTRACT FROM AUTHOR]

In this paper, the development is described of an efficient pyrene excimer signaling-based fluorescent sensor for the measurement of mercury ions in aqueous solutions based on thymine–Hg2+–thymine (T–Hg2+–T) coordination chemistry and the inclusion interaction of γ-cyclodextrin. Introduction of cyclodextrin can provide cooperation for the molecular level space proximity of the two labeled pyrene molecules, moreover the hydrophobic cavity of γ-cyclodextrin can also offer protection for the pyrene dimer's emission from the quenching effect of Hg2+ and enhance the fluorescence intensity of the pyrene excimer. To demonstrate the feasibility of the design, a bis-pyrene-labeled thymine-rich DNA strand was used as the detection probe. In the presence of Hg2+, stem-close-shaped DNA strands can be formed with the cooperation of γ-cyclodextrin and ideally predominantly emit the excimer fluorescence. The selectivity of the sensor for Hg2+ against other biologically and environmentally related metal ions is outstanding due to the high specificity of T–Hg2+–T formation. In addition, the pyrene excimer has a long fluorescence lifetime, which can tolerate intense background fluorescence interference from complex biological components, making it potentially applicable in the analysis of complex biological samples. [ABSTRACT FROM AUTHOR]

In the present study, a novel two-photon nanoprobe has been developed and successfully applied in glutathione (GSH) imaging in cell apoptosis of cancer tissue. [ABSTRACT FROM AUTHOR]

NaGdF 4 :Ce,Eu,Tb nanocrystals were successfully prepared by a one-step hydrothermal method with Ce 3+ ions as sensitizers, Eu 3+ and Tb 3+ ions as activators, and polyethylenimine (PEI) as surfactants. Color-adjustable fluorescence emission was achieved by the energy transfer effect between rare earth ions. Blue fluorescent carbon quantum dots (CDs) with a double UV response under 254 nm and 365 nm excitation were synthesized by a one-step hydrothermal method. A hydrophilic NaGdF 4 :Ce,Eu,Tb/CD composite ink was prepared by an easy physical mixing method. Because of the electrostatic self-assembly effect, the color adjustable luminescence was achieved in a few seconds, and the white light emission with color coordinates of (0.32, 0.32) was obtained. A dual-mode luminescence anti-counterfeiting pattern was designed and achieved by excitation with ultraviolet light at 254 nm and 365 nm., Competing Interests: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work reported in this manuscript., (This journal is © The Royal Society of Chemistry.)

We have developed a simple, low-cost, paper-based probe for the selective colorimetric detection of copper ions (Cu(2+)) in aqueous solutions. The bovine serum albumin (BSA)-modified 13.3-nm Au nanoparticle (BSA-Au NP) probe was designed to detect Cu(2+) ions using lead ions (Pb(2+)) and 2-mercaptoethanol (2-ME) as leaching agents in a glycine-NaOH (pH 12.0) solution. In addition, a nitrocellulose membrane (NCM) was used to trap the BSA-Au NPs, leading to the preparation of a nanocomposite film consisting of a BSA-Au NP-decorated membrane (BSA-Au NPs/NCM). The BSA-Au NPs probe operates on the principle that Cu deposition on the surface of the BSA-Au NPs inhibits their leaching ability, which is accelerated by Pb(2+) ions in the presence of 2-ME. Under optimal solution conditions (5 mM glycine-NaOH (pH 12.0), Pb(2+) (50 μM), and 2-ME (1.0 M)), the Pb(2+)/2-ME-BSA-Au NPs/NCM enabled the detection of Cu(2+) at nanomolar concentrations in aqueous solutions by the naked eye with high selectivity (at least 100-fold over other metal ions). In addition, this cost-effective probe allowed for the rapid and simple determination of Cu(2+) ions in not only natural water samples but also in a complex biological sample (in this case, blood sample).