Latest ArticlesThe conversion of methane to syngas (H2 and CO) is an important route to produce high value-added products. Oxidize methane into syngas in the absence of gaseous oxidants is an economical route. In this work, NiO-MgO composite is successfully synthesized via an impregnation method. At 764 K, methane is directly converted to syngas on the NiO-MgO without gaseous oxidants. A synergistic effect of NiO and MgO was observed, in which NiO induced lattice oxygen of MgO mobility to oxidize methane and suppressed the formation of intermediates for side reaction. As a result, NiO-MgO exhibited enhancement of catalytic activity with the H2 production rate of 1241.0 μmol g-1 min-1, which was 3.4 times higher than that of pure MgO. This work provides a direct guidance to understand of methane oxidation via lattice oxygen under low temperature (< 773 K).
Electrochemical reduction of CO2 to value-added chemicals holds promise for carbon utilization and renewable electricity storage. However, selective CO2 reduction to multi-carbon fuels remains a significant challenge. Here, we report that B/N-doped sp3/sp2 hybridized nanocarbon (BNHC), consisting of ultra-small nanoparticles with a sp3 carbon core covered by a sp2 carbon shell, is an efficient electrocatalyst for electrochemical reduction of CO2 to ethanol at relatively low overpotentials. CO2 reduction occurs with a Faradaic efficiency of 58.8%-69.1% for ethanol and acetate production at -0.5 ~ -0.6 V (vs. RHE), among which 51.6%-56.0% is for ethanol. The high selectivity for ethanol is due to the integrated effect of sp3/sp2 carbon and B/N doping. Both sp3 carbon and B/N doping contribute to enhanced ethanol production with sp2 carbon reducing the overpotential for CO2 reduction to ethanol.
Both glycosylation and phosphorylation exert crucial rule in multitudinous biological processes. For in-depth profiling of glycosylation and phosphorylation, a magnetic metal oxide is effectively coupled with inherently hydrophilic mesoporous channels (denoted as Fe3O4@TiO2@mSiO2-TSG). Based on the mechanism of hydrophilic interaction liquid chromatography (HILIC) and metal oxide affinity chromatography (MOAC), the Fe3O4@TiO2@mSiO2-TSG nanomaterial shows high capacity for simultaneously enriching glycopeptides and phosphopeptides. With human saliva collected in successive four days as practical biological sample, endogenous glycopeptides and phosphopeptides are efficiently enriched. Further gene ontology analysis reveals that the identified endogenous glycopeptides and phosphopeptides participate in diverse molecular functions and biological processes. This strategy is anticipated to promote variation analysis of salivary post-translational modifications.
The random movement and easy recombination of photoinduced charges lead to a low conversion efficiency for photocatalytic hydrogen evolution. The cocatalyst design is a promising route to address such problem through introducing an appropriate cocatalyst on the semiconductor photocatalysts to construct the high-efficiency heterojunctions. Herein, novel CoS/Nb2O5 heterojunctions were constructed via in-situ loading CoS cocatalyst on the surface of Nb2O5 nanosheets. Through the femtosecond-resolved transient absorption spectroscopy, the average lifetime of charge carriers for 10 wt% CoS/Nb2O5 (159.6 ps) is drastically shortened by contrast with that of Nb2O5 (5531.9 ps), strongly suggesting the rapid charge transfer from Nb2O5 to CoS. The significantly improved charge-transfer capacity contributes to a high photocatalytic hydrogen evolution rate of 355 μmol/h, up to 17.5 times compared with pristine Nb2O5. This work would provide a new design platform in the construction of photocatalytic heterojunctions with high charge-transfer efficiency.
Semiconductor photocatalysis holds great promise for breaking the inert chemical bonds under mild condition; however, the photoexcitation-induced modulation mechanism has not been well understood at the atomic level. Herein, by performing the DFT+U calculations, we quantitatively compare H2 activation on rutile TiO2(110) under thermo- versus photo-catalytic condition. It is found that H2 dissociation prefers to occur via the heterolytic cleavage mode in thermocatalysis, but changes to the homolytic cleavage mode and gets evidently promoted in the presence of photoexcited hole (h+). The origin can be ascribed to the generation of highly oxidative lattice O-radical (Obr·-) with a localized unoccupied O-2p state. More importantly, we identify that this photo-induced promotion effect can be practicable to another kind of important chemical bond, i.e., C–H bond in light hydrocarbons including alkane, alkene and aromatics; an exception is the C(sp1)-H in alkyne (HC≡CH), which encounters inhibition effect from photoexcitation. By quantitative analysis, the origins behind these results are attributed to the interplay between two factors: C-H bond energy (Ebond) and the acidity. Owing to the relatively high Ebond and acidity, it favors the C(sp1)-H bond to proceed with the heterolytic cleavage mode in both thermo- and photo-catalysis, and the photoexcited Obr·- is adverse to receiving the transferred proton. By contrast, for the other hydrocarbons with moderate/low Ebond, the Obr·- would enable to change their activation mode to a more favored homolytic one and evidently decrease the C–H activation barrier. This work may provide a general picture for understanding the photocatalytic R–H (R = H, C) bond activation over the semiconductor catalyst.
Real-time exploring the cellular endocytic pathway of viral capsid proteins (VCPs) functionalized nanocargos at the single-particle level can provide deep insight into the kinetic information involved in virus infection. In this work, porcine circovirus type 2 (PCV2) VCPs with different functions are modified onto the surface of upconversion nanoparticles (VCPs-UCNPs) to investigate the cellular internalization process in real-time. Clathrin-mediated endocytosis is found to be the essential uptake mechanism for these VCPs-UCNPs. Besides, it is verified that P1-UCNPs (PCV2 VCPs with nuclear localization signal, namely P1) can be easily assembled close to the perinuclear area, which is different from that of P2-UCNPs (PCV2 VCPs without nuclear localization signal, namely P2). Interestingly, multistep entry processes are observed. Particularly, confined diffusion is observed during the transmembrane process. The intracellular transport of VCPs-UCNPs is dependent on microtubules toward the cell interior. During this process, P1-UCNPs display increased velocities with active transport, while diffusion much faster around the perinuclear area. But for P2-UCNPs, there are only two phases involved in their endocytosis process. This study presents distinct dynamic mechanisms for the nanocargos with different functions, which would make a useful contribution to the development of robust drug delivery systems.
The efficiency of photocatalytic pollutant removal largely depends on the ability of the photocatalytic system to produce hydroxyl radicals (·OH). However, the capability of photocatalyst to produce ·OH is not strong at present. Advancing the capacity of photocatalytic system to produce ·OH has always been a tough problem and challenge in the field of environmental science. In this research, it was found that introducing nitric oxide (NO) into the graphitic carbon nitride (g-C3N4) photocatalytic system could memorably enhance the ability of producing ·OH group. This study provides a new idea for improving the capacity of photocatalytic ·OH production.
Hydrogen peroxide (H2O2) is a very simple bioactive small molecule. In living organisms, H2O2 plays an important role in intracellular signaling. It is involved in many physiological processes including cellular physiology, intracellular signaling, oxidative damage and disease progression. The tumor microenvironment enriched with H2O2. Several electrochemical sensors have been developed and some have been put on the market. Such electrochemical sensors provide efficient, cost-effective, rapid and highly selective method of H2O2 detection. So far, much progress has been made in the designing of materials and construction of H2O2 sensors. This review describes the advances in the application of H2O2 electrochemical sensors in cell detection. Enzyme-based sensors have been applied in diverse applications. In addition, recent advancements in nanotechnology have improved the development of nanozymes-based sensors. The application of noble metals, metal oxides, polymers, carbon materials and other two-dimensional materials in the design of H2O2 sensors are discussed in detail. Moreover, the bio-stimulant types of H2O2 sensor are summarized. Finally, the challenges and future perspectives in the application of H2O2 electrochemical sensors in biological detection are discussed.
Well-developed mitochondria-targeted nanocarriers for function regulation are highly desirable. Numerous studies have been conducted on the treatment of mitochondria-related diseases; however, further improvements are required to develop more effective drug delivery methods. Herein, we comprehensively introduce recent developments progress in rational design of mitochondria-targeted nanocarriers, and discuss the different strategies of available nanocarriers for targeting mitochondria. We also highlight the advantages and disadvantages of various carrier systems that are currently in use. Finally, perspective on new generation for mitochondria-targeted delivery systems in the emerging area of drug-based therapeutics is also discussed.
The emergence of disseminated metastasis is the leading cause of mortality in patients with malignant tumor. The pre-metastatic microenvironment, including the primary tumor-derived components, pre-metastatic niche (PMN), circulating tumor cells (CTCs), micro-metastases, and tumor immune microenvironment (TIM), are the crucial factors to initiate metastasis and form macro-metastases. It may be a more promising strategy for directly targeting pre-metastatic microenvironment-interrelated factors and cells before they have the chance to form secondary tumors to prevent metastasis. During recent years, a variety of nanosystems, with specific microstructures and functional properties, have been devised to selectively target pre-metastatic cells components and interrelated molecular, and exhibited strong potential on anti-metastatic therapy by absorbing and neutralizing primary tumor-derived components, preventing establishment of the PMN, eliminating the CTCs, eradicating the micro-metastases and modulating the TIM. In this review, we comprehensively review the emerging nanosystems based on the pre-metastatic microenvironments. Hopefully, this review can cast new lights for early preventing and attenuating metastatic progression.