Latest ArticlesIntegrating discrete plasmonic nanoparticles into assemblies can induce plasmonic coupling that produces collective plasmonic properties, which are not available for single nanoparticles. Theoretical analysis revealed that plasmonic coupling derived from assemblies could produce stronger electromagnetic field enhancement effects. Thus, plasmonic assemblies enable better performance in plasmon-based applications, such as enhanced fluorescence and Raman effects. This makes them hold great potential for trace analyte detection and nanomedicine. Herein, we focus on the recent advances in various plasmonic nanoassembles such as dimers, tetramers, and core-satellite structures, and discuss their applications in biosensing and cell imaging. The fabrication strategies for self-assembled plasmonic nanostructures are described, including top-down strategies, self-assembly methods linked by DNA, ligand, polymer, amino acid, or proteins, and chemical overgrowth methods. Thereafter, their applications in biosensor and cell imaging based on dark-field imaging, surface-enhanced Raman scattering, plasmonic circular dichroism, and fluorescence imaging are discussed. Finally, the remaining challenges and prospects are elucidated.
Peracetic acid (CH3C(O)OOH, PAA)-based heterogeneous advanced oxidation process (AOP) has attacked intensive interests due to production of various reactive species. Herein, Co(OH)2 nanoparticles decorated biochar (Co(OH)2/BC) was fabricated by a simple and controllable method, which was used to degrade tetracycline hydrochloride (TTCH) in water through PAA activation. The results indicated that 100% TTCH (C0 = 10 µmol/L) degradation efficiency was realized within 7 min at pH 7, with a high kinetic rate constant (k1) of 0.64 min−1 by the optimized Co(OH)2/BC. Material characterizations suggested that Co(OH)2 nanoparticle was successfully decorated on biochar, leading to more active sites and electronic structure alteration of biochar, thus greatly promoting the catalytic cleavage of PAA for radicals production. Then, the reactive oxygen species (ROS) quenching experiments and electron paramagnetic resonance (EPR) analysis demonstrated the key species were alkoxyl radicals (R–O•, mainly CH3CO2• and CH3CO3•), HO• and 1O2 in this system. Besides, density functional theory (DFT) calculation on Fukui index further revealed that the vulnerable sites of TTCH and three possible degradation pathways were proposed. This study can provide a new strategy for synthesis functional materials in PAA activation AOPs for removal of antibiotics in water.
Hydrogen evolution from water electrolysis has become an important reaction for the green energy revolution. Traditional precious metals and their compounds are excellent catalysts for producing hydrogen; however, their high cost limits their large-scale practical application. Therefore, the development of affordable electrocatalysts to replace these precious metals is important. Transition metal phosphides (TMPs) have shown remarkable performance for hydrogen evolution and garnered considerable interest in the field of electrolysis. Based on the detailed introduction of TMPs in previous studies, we have systematically summarized the preparation methods, improvement methods, and development opportunities of TMPs and proposed “stimulatory factors” as a fundamental factor affecting the performance of TMPs herein. As the core of this research, “stimulatory factors” can provide numerous solutions to improve the performance of TMP materials and provide a good starting point for TMP research.
In-depth exploration of the relationship among different adsorption sites is conducive to design of efficient adsorbents for target pollutants removal from water. In this study, the experiments, multivariate non-linear regression and density functional theory calculations are applied to explore the possible synergistic effects of three nitrogen (N)-containing sites on cow dung biochar surface for sulfamethoxazole (SMX) adsorption. Notably, a strong synergistic effect between pyridinic N and pyrrolic N sites was found for sulfamethoxazole adsorption. The adsorption energies of SMX on four pyrrolic N-coupled pyridinic N structures were −1.02, −0.41, −0.49 and −0.72 eV, much higher than the sum of adsorption energies (−0.31 eV) on pyrrolic N and pyridinic N. Besides, the alteration of Mulliken charge revealed that the simultaneous presence of pyridinic N and pyrrolic N improved the electron transfer remarkably from −0.459 e and 0.094 e to −0.649 e and 0.186 e, benefiting for SMX adsorption. This work firstly explored the possible synergies of adsorption sites on biochar surface for organic contaminants removal from water, which shed new lights on the adsorption mechanism and provided valuable information to design efficient adsorbents in the field of water treatment.
Compared with other types of breast cancer, triple-negative breast cancer (TNBC) has the characteristics of a high degree of malignancy and poor prognosis. Early diagnosis of TNBC through biological markers and timely development of effective treatment methods can reduce its mortality. Many Research experiments have confirmed that some specific miRNA expression profiles in TNBC can used as markers for early diagnosis. However, detecting the expression profiles of multiple groups of miRNAs according to traditional detection methods is complicated and consumes many samples. To address this issue, we developed a method for high-throughput, high-sensitivity quantitative detection of multiple sets of miRNAs (including miR-16, miR-21, miR-92, miR-199, and miR-342) specifically expressed in TNBC by rolling circle amplification (RCA) on fluorescence-encoded microspheres. Through the optimization of reaction system conditions, the developed method showed an extensive linear dynamic range and high sensitivity for all five miRNAs with the lowest limit of detection of 2 fmol/L. Meanwhile, this high-throughput detection method also appeared reasonable specificity. Only in the presence of a specific target miRNA, the fluorescence signal on the correspondingly encoded microspheres is significantly increased, while the fluorescence signal on other non-correspondingly encoded microspheres is almost negligible. Furthermore, this process exhibited good recovery and reproducibility in serum. The advantages of this method allow us to more conveniently obtain the expression profiles of multiple groups of TNBC-associated miRNAs, which is beneficial for the early detection of TNBC.
The misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems. Herein, a piezoelectic odd-layered MoS2 is prepared and applied to piezo-catalytic remove tinidazole (TNZ) and other antibiotic pollutants with aeration as a piezo-driving force. About 89.6% of TNZ can be degraded by MoS2 under aeration in the presence of dissolved oxygen with a reaction rate constant of 0.15 min−1, which is 2.4 times higher than that under N2 atmosphere and quiescence conditions. Quenching experiments and electron paramagnetic resonance (EPR) tests identify that singlet oxygen (1O2) and superoxide radical (O2•−) are dominant reactive oxygen species in MoS2/aeration system. These results demonstrate that MoS2 can trigger a piezoelectric effect and produce charge carriers to generate reactive oxygen species with dissolved oxygen (DO) for contaminant degradation with the turbulence and water bubbles rupture driven by aeration.
Two dimensional (2D) materials are promising gas sensing materials, but the most of them need to be heated to show promising sensing performance. Sensing structures with high sensing performance at room-temperature are urgent. Here, another 2D material, violet phosphorus (VP) nanoflake is investigated as gas sensing material. The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol. The VP nanoflakes are combined with graphene to form VP/G heterostructures-based NO sensor. An ultra-high gauge factor of 3 × 107 for ppb-level sensing and high resistance response of 59.21% with ultra-short recovery time of 6s for ppm-level sensing have been obtained. The sensing mechanism is also analysed by density functional theory (DFT) calculations. The adsorption energy of VP/G is calculated to be −0.788 eV, resulting in electrons migration from P to N to form a P−N bond in the gap between VP and graphene sheet. This work provides a facile approach to ablate VP for mass production. The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.
Developing multiplex sensing technique is of great significance for fast sample analysis. However, the broad emissions of most chemiluminescence (CL) luminophores make the multiplex CL analysis be difficult. In this work, a simple and sensitive CL analytical method has been developed for the simultaneous determination of Tb3+ and Eu3+ thanking to their narrow band emission. The technique was based on a mixed CL system of periodate (IO4−)-hydrogen peroxide (H2O2)-rare earth complexes, in which the reactive oxygen species (ROSs) especially singlet oxygen (1O2) can transfer its energy to the complex of Tb3+/Eu3+-ethylenediaminetetraacetic acid disodium salt (EDTA) and then produce the characteristic emissions of Tb3+ and Eu3+ without cross-interference. The further experiment found that the CL emissions of Tb3+ and Eu3+ could be catalyzed by the gold nanoparticles (AuNPs) via enhancing the yield of 1O2. The CL intensities of Tb3+ (at 490 nm) and Eu3+ (at 620 nm) increased linearly with concentration of Tb3+ and Eu3+. After the optimization of the CL sensing conditions, the limits of detection (LOD) were 5.0 × 10−9 mol/L and 8.0 × 10−7 mol/L for Tb3+ and Eu3+, respectively. Finally, the method has been applied for measuring the contents of Tb3+ and Eu3+ in leaching solution of mine sample and Tb3+/Eu3+-contained nanomaterials with satisfactory results. The present system provides a new CL technique for multiplex sensing with simplicity and high sensitivity.
Herein, copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed. The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2, 3-allenoate products. Meanwhile, the asymmetric 1,4-protosilylation of enynic orthoesters with PhMe2Si-Bpin was also studied. The chiral monopyridine imidazoline ligand was efficient to provide the asymmetric 1,4-protosilylation products with high enantioselectivity.
Li metal is considered an ideal anode material because of its high theoretical capacity and low electrode potential. However, the practical usage of Li metal as an anode is severely limited because of inevitable parasitic side reactions with electrolyte and dendrites formation. At present, single-component artificial solid electrolyte interphase cannot simultaneously meet the multiple functions of promoting ion conduction, guiding lithium ion deposition, inhibiting dendrite growth, and reducing interface side reactions. Therefore, multi-component design on Li metal surface is widely investigated to achieve long-term cycling. Herein, we report a Li2Ga-carbonate polymer interphase layer to solve volume changes, Li dendrites formation and side-reactions. As a result, the Li symmetric cell can be stabilized at 3.0 mA/cm2 in carbonate electrolyte with limited volume of 20 µL. Coupled with 13.6 mg/cm2 (loading of 2 mAh/cm2) LiFePO4 cathode, discharge capacity retains at 90% for over 150 cycles under limited electrolyte conditions. With such an alloy-polymer interphase layer, higher energy density Li metal batteries become prominent in the near future.