RSC Advances

Qian, Yingjie; Jeong, Sang Yung; Baeck, Sung-Hyeon; Jin, Myung-Jong; Shim, Sang Eun

doi: 10.1039/c9ra06709dpmid: 35528885

Porous organic polymers (POPs) with well-distributed and tunable functional groups acting as ligands for specific reactions are promising supports for confining useful novel metals such as Pd, Au, and Pd. Herein, a thiadiazole-containing POP has been successfully synthesized and used for immobilizing Pd species. Pd immobilized inside the micropores (2.3 nm) of the POP material is easily prepared owing to a large amount of the strong anchoring group, thiadiazole, which is intrinsically distributed in the as-prepared POP. The rigid thiadiazole-containing polymer can stabilize the central metal rather than poisoning it. The as-prepared catalyst shows excellent catalytic activity in Suzuki–Miyaura coupling reactions under mild reaction conditions and low catalyst loading. Importantly, the intrinsically distributed thiadiazole ligands can stabilize the Pd moiety, preventing aggregation and leaching, and afford excellent catalytic lifetimes. Consequently, the catalyst can be reused 10 times without a significant loss of its catalytic activity.

Li, Yuan; Xu, Donghui; Zhang, Dehang; Wei, Yuanchi; Zhang, Ruinan; Guo, Yuxiang

doi: 10.1039/c9ra07652bpmid: 35528907

In this paper, MnO2/MXene–Ti3C2 composites with different molar ratios were successfully prepared by a one-step hydro-thermal method, and the optimum proportion was confirmed by XRD and SEM comparative analysis. The optimum proportion of MnO2/MXene–Ti3C2 composites and MnO2 was used as a cathode material for magnesium batteries to carry out the electrochemical performance test. The results showed that the charge–discharge capacity of the MnO2/MXene–Ti3C2 composite was up to 105 mA h g−1, much higher than that of MnO2 (64 mA h g−1), and meanwhile it had good rate performance. At the same time, this also opened up the application of MXene–Ti3C2, a new two-dimensional material, in the field of battery electrode materials.

Wang, Xiaodong; An, Lu; Tian, Qiwei; Cui, Kuili

doi: 10.1039/c9ra06698epmid: 35528891

Hydrogen sulfide (H2S) is a key biosignal molecule in the human body. Endogenous H2S, as a gas delivery and protective agent in the body, is involved in a variety of physiological processes, including mediating vascular tone and neuromodulation. The production of abnormal H2S levels in the body is related to the occurrence of various diseases, so real-time monitoring of H2S in vivo is very important. However, traditional detection methods face enormous challenges in the in vivo detection of H2S owing to its high volatility and rapid catabolism. Optical probes developed in recent years with the advantages of high sensitivity, short response time, non-invasive nature and capacity for real-time monitoring can overcome the limitations of traditional detection methods and offer the possibility of real-time monitoring of H2S in cells and in vivo. In addition, the production of high concentrations of H2S is closely related to the formation of colon cancer, and H2S-activated treatment agents have been developed for use in this particular tumor microenvironment, which reduce the toxic side effects of traditional therapy on normal tissues and improves the treatment effect. This review summarizes the recent advances in H2S detection probes in vitro and in vivo, as well as H2S-activated tumor treatment agents.

Zhang, Yun; Shi, Shuyou; Xing, Jiajia; Tan, Wenqing; Zhang, Chenguang; Zhang, Lin; Yuan, Huan; Zhang, Miaomiao; Qiao, Jinjuan

doi: 10.1039/c9ra05304bpmid: 35528901

In this study, a novel colorimetric sensing platform was developed for the detection of S. aureus using dog immunoglobulin G (IgG) as the capture antibody and chicken anti-protein A immunoglobulin Y labeled with horseradish peroxidase (HRP-IgY) as the detection antibody. Dog IgG labeled with magnetic beads was used to capture S. aureus through the interaction between the Fc region of dog IgG and Staphylococcal protein A (SPA). HRP-IgY was introduced to recognize the residual SPA on the surface of S. aureus and to create a sandwich format, after which a soluble 3,3′,5,5′-tetramethylbenzidine (TMB) substrate was added. A stop solution was utilized to cease the enzymatic chromogenic reaction, and then optical density was read at 450 nm. Under optimal conditions, the proposed method displayed a low detection limit of 1.0 × 103 CFU mL−1 and a wide linear range of 3.1 × 103 to 2.0 × 105 CFU mL−1. This detection method exhibited high specificity against other foodborne bacteria. The recovery rates ranged from 95.2% to 129.2%. To our knowledge, this is the first report to employ dog IgG and chicken IgY as an antibody pair to detect S. aureus. This technique exhibits high application potential for S. aureus monitoring in various kinds of samples.

Zheng, ChangRan; Liu, QuanSheng

doi: 10.1039/c9ra07107epmid: 35528899

Persistent luminescence (PPL) materials have gained lots of attention and have been widely used in traffic signs, displays, medical diagnosis and architectural decoration. Single ion doped PPL materials with stable emission are excellent for practical applications, but it is difficult to cover the entire wavelength range. Here, a new cyan long-lasting phosphor CaSnO3:Lu3+ was successfully synthesized at 1200 °C by the conventional high temperature solid state method. From the X-ray photoelectron spectroscopy (XPS), it can be concluded that the Sn2+ ions exist in the crystal lattice because the doping of Lu3+ ions changes the valence state of the Sn ions. According to the thermally simulated luminescence (TSL), the continuous afterglow of CaSnO3:Lu3+ phosphors is produced by appropriate hole or electron traps, which are caused by doping the calcium stannate host with rare earth ions (Lu3+). The long-lasting phosphorescence (LLP) properties of the cyan phosphor were first discussed and the afterglow mechanism was expounded in detail. The excitation and the emission spectra of the phosphor revealed the characteristic broad peak of the Sn2+ ion. Typical afterglow behavior of the CaSnO3:Lu3+ phosphors was exhibited after power was turned off.

Nadargi, Digambar Y.; Dateer, Ramesh B.; Tamboli, Mohaseen S.; Mulla, Imtiaz S.; Suryavanshi, Sharad S.

doi: 10.1039/c9ra06482fpmid: 35528879

We report a facile, green synthesis of graphene/Ag/ZnO nanocomposites and their use as acetone sensors via a medicinal plant extraction assisted precipitation process. The choice of plant extract in combination with metal nitrates led to self-sustaining colloid chemistry. Along with the green synthesis strategy, structural, morphological and gas sensing properties are described.

Liu, Juan; Cheng, Hui; Xie, Hui; Luo, Guiling; Niu, Yanyan; Zhang, Shuyao; Li, Guangjiu; Sun, Wei

doi: 10.1039/c9ra06265cpmid: 35528916

A sensitive electrochemical method was proposed for the determination of luteolin based on platinum (Pt) nanoparticles decorating a biomass porous carbon (BPC) composite-modified carbon ionic liquid electrode (CILE). For Pt–BPC/CILE, a pair of well-defined redox peaks of luteolin appeared with enhanced peak currents and the positive movement of peak potentials, proving the electrocatalytic activity of the Pt–BPC nanocomposite for redox reaction. The results can be ascribed to the porous structure of BPC, the catalytic activity of Pt nanoparticles and their synergistic effects. Electrochemical parameters were calculated via cyclic voltammetry and differential pulse voltammetry. The results showed that the oxidation peak currents increased linearly with the concentration of luteolin in the range from 0.008 to 100.0 μmol L−1, with a detection limit of 2.6 ± 0.054 nmol L−1. The analytical performance of this sensor was checked by the detection of luteolin contents in a real Duyiwei capsule sample with satisfactory results.

Dong, Yingying; Qiu, Yan; Gao, Die; Zhang, Kailian; Zhou, Kai; Yin, Honggang; Yi, Gaoyi; Li, Jun; Xia, Zhining; Fu, Qifeng

doi: 10.1039/c9ra07466jpmid: 35528905

Most commercial permanent hair dyeing technologies are based on the oxidative process of p-phenylenediamine and its derivative materials. However, concerns about their toxicological issues have been raised throughout the years. Herein, we report an innovative surface coloration strategy for fabricating melanin-mimetic multicolor and low-toxicity hair dyes through sodium periodate-induced rapid deposition of eumelanin-like polydopamine (PDA) and pheomelanin-like PDA/cysteine co-deposited coatings on the hair surface. The color and morphology of the resulting hair were characterized in detail by several spectroscopy methods and the possible mechanism for the multi-coloring effects and structural differences of the melanin-mimetic coating was proposed. Our strategy eliminates the use of toxic dye precursors or organic solvents, and the favorable safety of the PDA-based formulations is demonstrated. The fabricated dyes can be applied to hair simply by combing, resulting in uniform multi-coloring effects within a short time. Furthermore, the melanin-mimetic hair dyes have excellent durability and ultraviolet protection performance. This work provides a facile and versatile methodology to develop the next generation of safe, sustainable and multicolor hair dyes and pave new avenues for advancing the field of surface coloration, nanoreactors, nanogenerators, energy storage materials and biomimetic sensing devices.

Pan, Yong; Chen, Shuang; Jia, Yanlin

doi: 10.1039/c9ra07702bpmid: 35528889

Although HfB12 is a promising surperhard material because of the boron cuboctahedron cage, the Vickers hardness of HfB12 remains controversial. We apply first-principles calculations to investigate the influence of a transition metal on the structural stability, Vickers hardness and thermodynamic properties of HfB12. The Vickers hardness of HfB12 is 39.3 GPa. In particular, the Vickers hardness of TM-doped HfB12, which are novel superhard materials, is larger than 40 GPa. The Vickers hardness of Re-doped HfB12 is up to 47.6 GPa. The improvement of Vickers hardness is that the introduction of an alloying element improves the localized hybridization between B and Hf, and then enhances the bond strength of the B–B covalent bond and the Hf–B bond. In addition, these alloying elements enhance the melting-point and Debye temperature of the HfB12. Therefore, we believe that alloying is an effective method to improve the Vickers hardness and thermodynamic properties of HfB12 superhard material.

Li, Zimin; Chanéac, Corinne; Berger, Gilles; Delaunay, Sophie; Graff, Anaïs; Lefèvre, Grégory

doi: 10.1039/c9ra03234gpmid: 35528876

The stability of magnetite under oxidizing hydrothermal conditions was evaluated at temperatures of 120, 150, 180 and 275 °C. A well-characterized sample of commercially-available magnetite with a particle size of approximately 690 nm was oxidized by dissolved oxygen (DO) under alkaline hydrothermal conditions in titanium autoclaves. In these trials, the DO was always in equilibrium with the gas phase oxygen that was air-derived and was located above the hydrothermal solution, which contained ammonium hydroxide at a pH25 °C of approximately 9.5. Samples recovered by filtration were analysed by X-ray diffraction and scanning electron microscopy, while Fe(ii)/Fe ratios were determined by titration in conjunction with spectrophotometry. Oxidation between 120 and 180 °C was found to generate high concentrations of maghemite and hematite in the product, with the latter compound having either a hexagonal bipyramidal or rhombohedral morphology. The oxidation kinetics was consistent with a diffusion controlled process. The reaction probably proceeded via the outward diffusion of ferrous ions from the magnetite, forming a magnetite/maghemite core/shell structure in conjunction with the dissolution of maghemite and reprecipitation of hematite. Oxidation at 275 °C presented different characteristics from those observed at the lower temperatures. Negligible amounts of maghemite were found, and the primary oxidation product was hematite with no specific morphologies. Moreover, the kinetics was slower than at 180 °C. This unexpected temperature effect is attributed to the rapid growth, at 275 °C, of a dense layer of hematite on the surface of the magnetite that impeded the oxidation of magnetite.