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Modifying the electrodes of electrochemical sensors is critical to enhance sensitivity, selectivity, and stability, ultimately improving both their effectiveness and performance. In this paper, recent advancements in electrochemical sensors are reviewed, focusing on the utilization of layered double hydroxides (LDHs). The first section explores the advantageous and disadvantageous aspects of electrochemical sensing. Benefits include rapid response, ease of operation, and cost-effectiveness, while drawbacks concern the potential instability of prolonged use, susceptibility to interference, and the risk of biomolecule inactivation. Following this, the second section delves into the synthesis, constituents, and structure of LDHs. Moreover, after introducing the chemical mechanisms and functions of LDHs in electrochemical sensors, we concentrate on diverse modifying materials of LDHs and their different performances. Finally, the applications of LDHs in electrochemical sensing across different fields are discussed. This review aims to facilitate the continued advancement for applying LDHs in electrochemical sensors, as well as inspire the evolution of electrochemical sensing technology.

Nanomedicines for drug delivery and imaging-guided cancer therapy is a rapidly growing research area. The unique properties of nanomedicines have a massive potential in solving longstanding challenges of existing cancer drugs, such as poor localization at the tumor site, high drug doses and toxicity, recurrence, and poor immune response. However, inadequate biocompatibility restricts their potential in clinical translation. Therefore, advanced nanomaterials with high biocompatibility and enhanced therapeutic efficiency are highly desired to fast-track the clinical translation of nanomedicines. Intrinsic properties of nanoscale covalent organic frameworks (nCOFs), such as suitable size, modular pore geometry and porosity, and straightforward post-synthetic modification via simple organic transformations, make them incredibly attractive for future nanomedicines. The ability of COFs to disintegrate in a slightly acidic tumor microenvironment also gives them a competitive advantage in targeted delivery. This review summarizes recently published applications of COFs in drug delivery, photo-immuno therapy, sonodynamic therapy, photothermal therapy, chemotherapy, pyroptosis, and combination therapy. Herein we mainly focused on modifications of COFs to enhance their biocompatibility, efficacy and potential clinical translation. This review will provide the fundamental knowledge in designing biocompatible nCOFs-based nanomedicines and will help in the rapid development of cancer drug carriers and theranostics.

The development of efficient strategies for the sustainable detoxification of mustard gas simulants has longstanding demand for human safety. Here, we present for the first time a photo- and sono-catalyzed selective detoxification of mustard gas simulants under ambient conditions using conveniently prepared porous organic polymer (POP) catalysts. We developed a microwave-assisted synthesis of three isomeric tetraphenylethylene-based POPs (TPo, TPm, and TPp) bearing fully sp2-hybridized carbon frameworks. Among the three isomers, TPmefficiently generated 1O2, whereas TPpgenerated both O2.–and HO.under visible light irradiation, both TPmand TPpefficiently generated ROS to selectively convert 2-chloroethyl ethyl sulfide (CEES) into nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) in the atmospheric conditions, through a known conversion mechanism. TPmand TPpcan also generate 1O2under ultrasound irradiation. This work provides insight into designing new POP photo- and sono-catalysts to generate ROS in widespread applications.

Solar light-driven fuel production from carbon dioxide using organic photocatalysts is a promising technique for sustainable energy sources. Band gap engineering in sustainable organic photocatalysts for improving efficiency and fulfilling the requirements is highly anticipated. Here, we present a new strategy to engineer the band gap in covalent organic framework (COF) photocatalysts by varying the push–pull electronic effect. To implement this strategy, we have designed and synthesized four different COFs using a tripodal amine 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)tris(([1,1′-biphenyl]-4-amine)) [Ttba] with 1,3,5-triformylbenzene (COF-1), 2,4,6-triformylphloroglucinol (COF-2), 2,4,6-triformylphenol (COF-3), and 2,4,6-triformylresorcinol (COF-4). On varying the number of hydroxyl units in the aldehyde precursor, the resulting COFs allow the fine-tuning of their band gap and band edge positions and result in different morphologies with varying surface areas. The enhanced optical properties of COF-3and COF-4with very suitable band gaps of 2.02 and 1.95 eV, respectively, enable them to demonstrate a high-efficiency photobiocatalytic system for NADH photoregeneration and enhanced visible light-driven formic acid production at a rate of 226.3 μmol g–1in 90 min. The triazine core enables efficient charge separation, while the hydroxyl groups induce an electronic push–pull effect, regulating their photocatalytic efficiency. The results demonstrated the morphology-guided enhanced surface area and dual keto–enol tautomerism-induced push–pull effect in asymmetrical charge distribution as key features in the fine-tuning of the photocatalysts.

Three-dimensional molecular architectures self-assembled with tripodal and tetratopic donors are valuable because of their encapsulation properties. Here, we present Co(I)–Fe(II)–Pd(II) heterotrimetallic trifacial barrel 1, which was self-assembled using a newly synthesized tetratopic donor [CpCo(CbR4)] [L; Cp = cyclopentadienyl, Cb = cyclobudiene, and R = 4-(4-pyridylphenyl)] and a 90° acceptor [cis-(dppf)Pd(OTf)2] (A1; dppf = (diphenylphosphino)ferrocene and OTf = CF3SO3–). The heterotrimetallic barrel 1exhibited selective 1:1 interaction with a N,N′-dimethyl-1,4,5,8-naphthalenetetracarboxylic diimide guest, as revealed by 1H NMR analysis. The self-assembly of donor Lwith two other Ru(II)-based 180° acceptors [(p-cymene)2Ru2(OO∩OO)(OTf)2] [OO∩OO = 6,11-dioxido-5,12-naphthacenedione (A2) and oxalate (A3)] resulted in tetragonal-prismatic cages. Self-assembly using the longer acceptor A2provided rare isomers of a tetragonal-prismatic cage by varying the orientation of the cyclopentadienyl moiety out–out (2a) or out–in (2b) of the cavity, whereas self-assembly using the shorter acceptor A3selectively resulted in the tetragonal-prismatic cage 3. The three-dimensional molecular architectures 1–3were characterized by combined spectroscopic and elemental analyses. The structures of molecular barrel 1and prismatic cage 3were elucidated by single-crystal X-ray analysis.

Coordination-driven self-assembly of m-bis[3-(4-pyridyl)pyrazolyl]xylene (L) and [(p-cymene)2Ru2(OO∩OO)2(OTf)2] (A1) (OO∩OO = 6,11-dioxido-5,12-naphthacenedione) in methanol resulted in a mixture of [2]catenane 1and macrocycle 2, and self-assembly in nitromethane resulted in pure macrocycle 2, whereas the coordination-driven self-assembly of Land similar acceptors [(p-cymene)2Ru2(OO∩OO)2(OTf)2] [OO∩OO = 5,8-dioxido-1,4-naphthoquinonnato (A2); 2,5-dioxido-1,4-benzoquinonato (A3); oxalato (A4)] resulted in the formations of monomeric macrocycles 3–5, respectively. All self-assembled macrocycles were obtained in excellent yields (>90%) as triflate salts and were fully characterized by multinuclear NMR, elemental analysis, and electrospray ionization mass spectrometry (ESI-MS). The structures of [2]catenane 1and macrocycles 5were confirmed by single-crystal X-ray diffraction analysis. The X-ray structure of 1confirmed an edge-to-face interaction between the tetracene moiety in parallel-displaced π–π stacks (3.5 Å), and CH···π (2.5 Å) stabilizes the [2]catenane topology. Macrocycles 2–5were assessed for anticancer activities using human cancer cell lines of different origins, and the macrocycle 3was found to exhibit the best inhibitory effect and to do so in a dose-dependent manner. Further examination with the Tali apoptosis assay suggested the growth inhibitory effect of 3involved the induction of the programmed cell death, and this suggestion was supported by observations of PARP and caspase 3 cleavage after treating cells with 3. In addition, exposure to 3increased the expression of Bax and repressed the expression of Bcl-2, thus indicating the involvement of macrocycle 3upstream of Bax and Bcl-2 in the apoptotic signaling pathway. Macrocycle 3also tended to repress metastasis as evidenced by changes in the transcriptional expressions E- and N-cadherin (markers of metastasis). Furthermore, a stability assay demonstrated macrocycle 3remained stable at high concentration.

ABSTRACTDespite their potential role in the spread of foot-and-mouth disease (FMD), the immune response and viral persistence in FMD virus (FMDV)-infected Indian buffaloes (Bubalus bubalis) have been unexplored. We found similar kinetics of neutralizing antibody responses in the sera and secretory fluids of buffaloes following experimental FMDV Asia 1 infection, but the lymphocyte-proliferative response in infected buffaloes was of low magnitude. Despite inducing a significant systemic and secretory immune response, viral persistence seems to be a common outcome in buffaloes following FMDV Asia 1 infection, which is associated with a weak cellular immune response.

A letter to the editor is presented in response to the article "4Cs and 1R syndrome" in the June 2014 issue.