Latest ArticlesCompared to organic thin films, organic single crystals offer significant potential in organic phototransistors (OPTs) due to their enhanced charge transport, large surface area, and defect-free nature. However, the development of n-type semiconductors has lagged behind p-type semiconductors. To enhance semiconductor device performance, a doping process can be employed, which typically involves the introduction of charged impurities into the crystalline semiconducting material. Its aim is to reduce the Ohmic losses, increase carrier density, improve transport capabilities, and facilitate effective carrier injection, ultimately enhancing the electrical properties of the material. Traditional doping processes, however, often pose a risk of damaging the structure of single crystals. In this study, we have synthesized novel cyano-substituted chiral perylene diimides, which self-assemble into two-dimensional single crystals that can be used for n-type semiconductor devices. We have employed a surface doping strategy using diethylamine vapor without disrupting the crystal structure. The fabricated devices exhibit significantly higher charge transport properties after doping, achieving a maximum electron mobility of 0.14 cm2 V−1 s−1, representing an improvement of over threefold. Furthermore, the optoelectronic performance of the doped devices has significantly improved, with the external quantum efficiency increased by over 9 times and the significantly improved response time. These results suggest that our surface doping technology is a promising way for enhancing the performance of 2D organic single-crystal OPTs.
Photosynthesis is the process through which living plants utilize photosynthetic pigments, such as chlorophyll, to convert CO2 and water into organic compounds and release O2 under visible light. In this study, we have successfully constructed a fluorescent supramolecular polymer (P5Py2/Zn/Gen)n by employing orthogonal pillar[5]arene-based molecular recognition and metal ion coordination. Within the supramolecular polymer, the guest molecule Gen unit acts as a light-harvesting moiety, as the ACQ effect is inhibited by host-guest interactions, while the (Py)2/Zn center serves as a catalytic site. By employing this orthogonal self-assembly strategy, we have enhanced the stability of both the donor and acceptor in catalyzing the reduction of p-nitrophenol to p-aminophenol. Moreover, this photocatalyst can be reused at least 5 times without significant conversion loss. These findings provide a pathway for constructing a recyclable artificial LHS that mimics the entire photosynthesis process.
A rhodium(Ⅲ)-catalyzed hydrosilylation/cyclization reaction of cyclohexadienone-tethered α, β-unsaturated aldehydes (1, 6-dienes) with triethylsilane is described, providing a series of cis-hydrobenzofurans, cis-hydroindoles, and cis-hydroindenes bearing silyl enol ether in good to excellent yields and excellent stereoselectivities. Additionally, the versatility of this method was demonstrated through a gram-scale experiment and various downstream transformations, highlighting its utility.
Theranostic carbon dots (CDs) have attracted widespread attention recently due to their tunable optical properties and diverse bioactivities. Beyond fluorescent imaging application, the photothermal property endows CDs with the potential for microbial inactivation. However, realization of the effective conversion between fluorescence and heat in one CD system has rarely been reported. Herein, we provide a simple strategy for targeted microbial theranostics based on 4-carboxyphenylboronic acid-derived CDs (PCBA-CDs) which possess concentration-dependent photoluminescence/photothermal features. At lower concentrations, PCBA-CDs show bright and stable fluorescent signals ranging from blue to green. The fluorescence intensity gradually decreases with increasing concentration, while on the contrary, the photothermal effect of PCBA-CDs ascends progressively due to the rearrangement of electronic transitions in aggregated CDs. PCBA-CDs also demonstrate high affinity to the polysaccharide structures on the surface of microbe which allows rapid microbial fluorescence imaging as well as specific photothermal ablation of pathogens in skin wounds using PCBA-CDs at lower and higher concentrations, respectively. This study supplies a facile nanotheranostic strategy for just-in-time microbial management using bioactive CDs.
The elimination of neonicotinoids (NEOs) from water has been a research priority due to their threats to human health and ecosystems. In this study, we established the heterogeneous peroxymonosulfate (PMS) activation system using manganese catalyst (Mn NC) and cobalt catalyst (Co NC) to trigger the nonradical oxidation and synergistic oxidation pathway, respectively to remove NEOs. The results showed that the nonradical oxidation system exhibited superior NEOs degradation capability. The composition of organic pollutants in wastewater significantly impacted subsequent degradation processes. The charge distribution and reaction sites of various NEOs were analyzed using density functional theory (DFT) calculations, and it demonstrated the electron distribution and activity of NEOs were significantly influenced by the type and number of substituents. Nitro group (–NO2) and cyanide group (–CN) were identified as strong electron-withdrawing groups and prone to be attacked by negatively charged radicals. The transformation of NEOs was analyzed, and result showed that the C and N sites adjacent to the nitro group and cyanide group were more susceptible to oxidation attacks. S and N atoms, which possess strong electronegativity and high electron cloud density, were identified as key active sites in the degradation pathway. The outcomes of this study provide valuable guidance for the oriented regulation of oxidation pathways towards efficient removal of NEOs in water.
Diabetes mellitus considerably affects bone marrow mesenchymal stem cells (BMSCs), for example, by inhibiting their proliferation and differentiation potential, which enhances the difficulty in endogenous bone regeneration. Hence, effective strategies for enhancing the functions of BMSCs in diabetes have far-reaching consequences for bone healing and regeneration in diabetes patients. Tetrahedral framework nucleic acids (tFNAs) are nucleic acid nanomaterials that can autonomously enter cells and regulate their behaviors. In this study, we evaluated the effects of tFNAs on BMSCs from diabetic rats. We found that tFNAs could promote the proliferation, migration, and osteogenic differentiation of BMSCs from rats with type 2 diabetes mellitus, and inhibited cell senescence and apoptosis. Furthermore, tFNAs effectively scavenged the accumulated reactive oxygen species and activated the suppressed protein kinase B (Akt) signaling pathway. Overall, we show that tFNAs can recover the proliferation and osteogenic potential of diabetic BMSCs by alleviating oxidative stress and activating Akt signaling. The study provides a strategy for endogenous bone regeneration in diabetes and also paves the way for exploiting DNA-based nanomaterials in regenerative medicine.
Membrane will inevitably reach the end of its lifespan due to the irrecoverable fouling accumulation in membrane bioreactors (MBRs) during long-term operation. Herein, we developed an eco-friendly membrane regeneration strategy with triethyl phosphate (TEP), which successfully prolonged the lifespan of end-of-life (EOL) polyvinylidene fluoride (PVDF) membranes in a large-scale MBR. The regenerated (Rg) membrane exhibited a water permeance of 534.8 ± 45.7 L m−2 h−1 bar−1, along with stable rejection rate, which was comparable with that of the new membrane. Furthermore, compared to the membrane subjected solely to preliminary cleaning, the Rg membrane presented a more hydrophilic surface due to the combination of preliminary cleaning and solvent-based processing. Besides, the Rg membrane presented less fouling propensity with the critical flux of 15.2 L m−2 h−1, significantly higher than that of the EOL membrane (4.0 L m−2 h−1). Importantly, the membrane regeneration strategy was capable of guaranteeing the effluent quality in MBR systems for treating real municipal wastewater. This study provides an eco-friendly membrane regeneration strategy for effectively removing the irrecoverable foulants, thereby promoting the advancement of sustainable membrane-based wastewater treatment technology.
Exosomes as authigenous nanovesicles secreted by living cells represent a significant class of biomaterials. By virtue of their unique roles in intercellular communication, exosomes can mediate intercellular information/cargoes exchange as messenger and facilitate drug delivery as smart vehicles. Oral medication is the most clinically relied upon route of administration and can achieve both topical and systemic therapeutic effects after absorption. Exosomes and exosome-derived vectors have shown to be of high value in oral drug delivery, since they enable efficient oral delivery of therapeutic molecules by targeting intestinal epithelial cells. In recent years, exosome-biomimetic nanocarriers have emerged as an important catalyzer in innovating oral drug delivery systems. In this work, we roundly reviewed the biogenesis and functions of exosomes, their extraction and characterization methods, resources available for exosomes harvest, and design philosophy of exosome-derived vehicles, particularly highlighting the oral delivery application of exosome-biomimetic nanocarriers for diverse medicines. Accumulating evidence suggests that exosome-biomimetic nanocarriers hold great promise for oral delivery of intractable drugs with potential biopharmaceutic issues.
Understanding the luminescence mechanisms and regulating the emission centers of carbon dots (CDs) are important for advancing their related applications. In this work, we systematically investigate the formation processes of multi-emission centers in CDs synthesized through a bottom-up approach by controlling the solvothermal reaction temperature. CDs synthesized at a lower temperature (140 ℃, 140-CDs) exhibit smaller particle sizes (3–4 nm) with dominant green–yellow emission, while CDs synthesized at a higher temperature (180 ℃, 180-CDs) exhibit larger particle sizes (8–9 nm) with enhanced red emission and emerging near-infrared (NIR) emission. The green–yellow emission and red emission originate from the core state and the surface-related state, respectively, and the emissions could be regulated by temperature-controlled dehydration and carbonization processes. The clear NIR emission center in 180-CDs is attributable to the increased content of radical defects in the cores during the increased dehydration and carbonization processes during higher-temperature solvothermal treatment.
Recently, the composite of soft conductive substrates, such as carbon fiber (CF), with metal-organic frameworks (MOFs) has been employed in a myriad of applications. The composite material has demonstrated exceptional potential in the realm of electrochemical sensing platforms. However, the rapid growth of MOFs on the surface of CF remains a challenge. Herein, we propose a simple galvanostatic method as an effective strategy for rapidly growing zeolitic imidazolate frameworks (ZIFs) on CF, and obtain nano-caltrop-like ZIFs modified CF (NC-ZIFs/CF) glucose (Glu) sensor platform with distinctive morphology. The prepared NC-ZIFs/CF demonstrated significant electrocatalytic activity towards the oxidation of Glu in alkaline media, characterized by a pronounced augmentation in oxidation current density. At an applied potential of 0.4 V, NC-ZIFs/CF exhibited a remarkably broad detection range (3–30,000 µmol/L) and demonstrated outstanding selectivity, repeatability and reproducibility. Additionally, the NC-ZIFs/CF was efficaciously employed for the detection of blood Glu levels in the serum of both normoglycemic and hyperglycemic patients, obtaining highly reliable results. This work demonstrates the feasibility of using galvanostatic method assembly to induce the growth of MOFs on conductive substrates, providing new ideas for electrocatalysis sensors and other electrochemical applications.