Latest ArticlesQuantum dots-hydrogel composites are promising new materials that have attracted extensive attention due to their incomparable biocompatibility and acceptable biodegradability, leading to enormous potential applications for various fields. This review summarizes the recent advances in quantum dots-hydrogel composites with a focus on synthesis methods, including hydrogel gelation in quantum dots (QDs) solution, embedding prepared QDs into hydrogels after gelation, forming QDs in situ within the preformed gel and cross-linking via QDs to form hydrogels. In particularly, biomedical applications as bioimaging, biosensing and drug delivery are also reviewed, followed by a discussion on the inherent challenges of design optimization, biocompatibility and bimodal applications and the prospect of the future development. These results will guide the development of quantum dots-hydrogel composites and provide critical insights to inspire researchers in future.
In recent years, the strategy of inhibiting the interactions of p53 with murine double minute 2 (MDM2) and murine double minute X (MDMX) has been proved to be a promising approach for tumor therapy. However, the poor proteolytical stability and low intracellular delivery efficiency of peptide inhibitors limit their clinical application. Here, we designed and synthesized the bicyclic stapled peptides based on p53 by combining all-hydrocarbon stapling and lactam stapling strategies. We demonstrated that bicyclic stapled peptide p53-16 significantly improved α-helicity and proteolytic stability. Especially, p53-16 showed nanomolar binding affinity for MDM2 and MDMX. In addition, p53-16 could penetrate the cell membrane, and selectively inhibited the activity of tumor cells via activating p53 pathway in vitro. Our data suggest that p53-16 is a potential dual inhibitor of MDM2 and MDMX interactions. The bicyclic stapling strategy is a promising drug design strategy for protein–protein interactions inhibitors.
The ability of plasmonic nanostructures to efficiently harvest light energy and generate energetic hot carriers makes them promising materials for utilization in photocatalytic water spitting. Apart from the traditional Au and Ag based plasmonic photocatalysts, more recently the noble–metal–free alternative plasmonic materials have attracted ever–increasing interest. Here we report the first use of plasmonic zirconium nitride (ZrN) nanoparticles as a promising photocatalyst for water splitting. Highly crystalline ZrN nanoparticles with sizes dominating at 30–50 nm were synthesized that exhibit intense visible and near–infrared absorption due to localized surface plasmon resonance (LSPR). Without utilizing any noble metal cocatalysts such as Pt, the plasmonic ZrN nanoparticles alone showed stable photocatalytic activity for H2 evolution in aqueous solution with methanol as sacrificial electron donor. The addition of a cobalt oxide (CoOx) cocatalyst can facilitate the separation of photogenerated charge carriers and further improve the photocatalytic activity. The optimized CoOx modified ZrN photocatalyst was observed not only to activate the O2 evolution reaction with presence of electron acceptor, but also to drive overall water splitting for the simultaneous H2 and O2 evolution in the absence of any sacrificial agents.
Cell is the most basic unit of the morphological structure and life activity of an organism. Learning the composition, structure and function of cells, exploring the life activities of cells and studying the interaction between cells are of great significance for human cognition and control of the life activities of organisms. Therefore, rapid, convenient, inexpensive, high-precision and reliable methods of cell separation and analysis are being developed to obtain accurate information for the study of cytology and pathology. Microfluidic chip is a new emerging technology in recent years. It has a micromanufacturing structure, which can not only realize the precise space-time control of fluid and cells, but also reproduces the three-dimensional dynamic microenvironment of cell growth in the body. In addition, the microfluidic chip has unique microphysical properties and facilitates the integration of microdevices, which provides the possibility of real-time monitoring, continuous culture, separation and enrichment, and even in situ analysis of cells. In this review, we summarized recent advances in the development of different techniques for cell isolation and analysis on microfluidic platforms. Focus was put on biochemical and physical methods for cell separation on microfluidic chips. Subsequent cell analysis depending on fluorescence, Raman, cytomicroscopic imaging, mass spectrometry and electrochemical methods also was remarked. Through analyzing and learning the advantages and disadvantages of different technologies, we hope that microfluidic chips will continue to be improved and expanded for medical and clinical applications.
Exploiting efficient and recyclable photocatalysts is a vital matter for environmental purification. Herein, cerium vanadate (CeVO4) sub-microspheres and silver nanowire (AgNW)@CeVO4 with core-shell architecture as photocatalysts are rationally constructed by hydrothermal approach. The AgNW@CeVO4 photocatalyst obtained by depositing CeVO4 on the surface of Ag NWs possess one dimensional continuous structure, which expand the optical absorption range and reduce the band gap of CeVO4 photocatalyst. Moreover, the resultant AgNW@CeVO4 photocatalyst demonstrates superior photocatalytic performance in the degradation of rhodamine B, methylene blue, and 4-nitrophenol pollutants upon solar light irradiation, compared with pure CeVO4. The excellent photocatalytic activity can be ascribed to the introduction of Ag NWs, which afford rapid charge transport channels and reservoir for the electrons in the AgNW@CeVO4 heterostructure to promote separation of electron–hole pairs. The first-principles investigations reveal increase of adsorption energy of oxygen molecules on the CeVO4 surface with the presence of Ag. Meanwhile, Ag NWs can further improve the photocatalytic efficiency of the AgNW@CeVO4 based on the plasmonic effect. More importantly, the good structural stability and recyclability of AgNW@CeVO4 are observed due to the strong synergistic effect, which ensures long-term usability of photocatalyst and great promise in water purification. This work can offer valuable reference into designs and construction of Ce-based heterojunction photocatalysts for environmental remediation.
Fabrication of multifunctional nanoplatform to in situ monitor Fenton reaction is of vital importance to probe the underlying reaction process and design high-performance catalyst. Herein, a hybrid catalyst comprising of single-crystalline Au nanoparticles (SC Au NPs) on reduced graphene oxide (RGO) sheet was prepared, which not only exhibited an excellent 1O2 mediated Fenton-like catalytic activity in promoting rhodamine 6G (R6G) degradation by activating H2O2, but also displayed a sensitive surface-enhanced Raman spectroscopy (SERS) detection performance to R6G with a linear response range from 1.0 × 10-8 mol/L to 1.0 × 10-5 mol/L thus providing a powerful and versatile nanoplatform for in situ SERS monitoring Fenton-like catalytic reaction. The integration of catalytic and SERS activities into a single nanostructure are expected to provide great potentials for practical applications in environmental catalysis.
The leaching and non-recoverability of mental ions have always limited the practical application of Fenton-like processes. For the first time, we synthesized molybdenum phosphide (MoP) with dual active sites for the degradation of diclofenac (DCF) in the Fenton-like process. The DCF degradation rate constant (k) of MoP + H2O2 process was calculated to be 0.13 min-1 within 40 min, indicating a highly efficient catalytic ability of MoP. In addition, this catalyst exhibits a stable structure and good activity, which could apply in a broad pH range, different ions solution and real wastewater condition. Accordingly, this efficient catalytic capability may be attributed to the presence of the metal sites Moδ+ and the electron-rich sites Pδ− in MoP, which could induce the generation of hydroxyl radical (·OH) and superoxide radical (·O2−) through electron transfer, resulting in the effective removal of DCF. This study provides an idea for the optimization of Fenton-like technologies and environmental remediation.
Selective functionalization of C–F bonds in trifluoromethyl groups has recently received a growing interest, as it offers atom- and step-economic pathways to access highly valuable mono- and difluoroalkyl-substituted organic molecules using simple and inexpensive trifluoromethyl sources as the starting materials. In this regard, impressive progress has been made on the defluorinative functionalization reactions that proceed via radical intermediates. Nevertheless, it is still a great challenge to precisely control the defluorination process, due to the continuous decrease of the C–F bond strength after the replacement of one or two fluorine atoms with various functionalities. This review article is aimed to provide a brief overview of recently reported methods used to functionalize C–F bonds of CF3 groups via radical intermediates. An emphasis is placed on the discussion of mechanistic aspects and synthetic applications
Increasing active metal sites is a valid approach to improve the catalytic activity of the catalyst. Co3+ is the main active metal site of Co-based catalysts. In this research work, through the partial transformation of CoFePBA (CFP) via low-temperature heat treatment, the effective control of the Co3+/Co2+ ratio has been achieved. The partial transformation strategy of low-temperature heat treatment can not only maintain the original framework structure of CFP, but also increase more active sites. The characterization results show that the CFP-200 sample obtained via heat treatment at 200 ℃ for 2 h under N2 atmosphere has the highest Co3+/Co2+ ratio. As an oxygen evolution reaction electrocatalyst, CFP-200 shows the best electrocatalytic activity among all samples. In 1.0 mol/L KOH electrolyte, the overpotential is 312 mV at a current density of 10 mA/cm2. Therefore, low-temperature heat treatment provides an effective method for preparing low-cost and high-efficiency electrocatalysts.
Oximes derivatives have been vastly used in organic synthesis. In this review, C(sp3)−H bond functionalization of oximes derivatives via iminyl radical induced 1, 5−hydrogen atom transfer was discussed. According to the different type of products, this review was divided into three parts: (1) C(sp3)−H bond functionalization for C−C bond formation. (2) C(sp3)−H bond functionalization for C−N bond formation. (3) C(sp3)−H bond functionalization for C−S, C−F bond formation.