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The transfer of configuration information from supramolecular helices is a ubiquitous phenomenon in nature. DNA and proteins often change their helical structure in response to particular external stimuli and can activate important related events through sophisticated mechanisms. Attempts to create artificial multiple-stranded helicates that can adjust the configuration under external stimuli have also met with limited success. Using a simple ligand, we now show multiple-stranded lanthanide helicates that transform efficiently. Lanthanide and ligand are successfully self-assembled into different multiple helical supermolecular clusters using different templates. Additionally, these intelligent supermolecular transformers can also be transformed by different external stimuli and realize the selective recognition and fixation of the corresponding ions and molecules.

Nowadays, with the development of technology, the safety performance of traditional single- or dual-mode luminescent materials used for anti-counterfeiting has been significantly reduced due to their single and predictable readout process. In this work, we have synthesized a rare earth single-doped material Mg2SnO4:Tb3+ with persistent luminescence, photo-luminescence and photo-stimulated luminescence and found a distinction of emission color between photo-luminescence, persistent luminescence and photo-stimulated luminescence. Thus, a multimodal dichromatic luminescence was achieved by single doping. Based on these luminescence properties, we made chalks from the obtained samples to write confidential information on a black substrate and designed a multilevel encrypted strategy for anti-counterfeiting, which proves that the obtained materials have great application potential in the field of information security.

It is challenging to develop highly stable lanthanide luminescent sensors for detecting heavy metal ions and nitroaromatics in view of the human health and environmental security. To this end, two water stable Ln-MOFs with the chemical constitution of {[Ln(HL)]·3DMF·3H2O}n (Ln = Eu, LZG-Eu and Ln = Tb, LZG-Tb) have been developed solvothermally using a multidentate ligand (H4L) with the central phenyl backbone bisubstituted by 2,6-pyridine-dicarboxylic acid at the para-position, H4L = 1,4-bis(2',2'',6',6''-tetracarboxy-1,4':4,4''-pyridyl)benzene. Single crystal analysis demonstrates that two novel Ln-MOFs feature 4,4,4-connected nets with an unprecedented topology symbol of {42·6·83}2{42·62·82}{42·84} and contain two kinds of one-dimensional channels. Powder X-ray diffraction as well as the luminescence determination results indicate that they retain their crystallinity and structural integrity in harsh acidic and basic conditions with pH in the range of 4-11. Moreover, they are highly luminescent, which makes them excellent chemical sensors for detecting Cu2+ and 4-NP (4-nitrophenol) with high selectivity and sensitivity in aqueous media such as deionized water, tap water, and river water based on distinct quenching effects. To the best of our knowledge, their detection limits are lower than those documented so far. In addition, the quenching efficiency of 4-NP was retained in the presence of interfering ions even after the compounds were used for five cycles, which makes them attractive, reliable, visual, and recyclable luminescent Ln-MOF sensor materials for 4-NP. The recognition mechanism for Cu2+ could be attributed to the dissociation of the main framework induced by Cu2+ and the subsequent formation of a Cu2+ coordination species and that for 4-NP is considered to be multi-quenching mechanisms dominated by competition absorption.

Surface-enhanced Raman scattering (SERS) sensing has always been considered as a kind of high-efficiency analysis technique in different areas. Herein, we report a AgNPs decorated 3D bionic silicon (Si) nanograss SERS substrate with higher sensitivity and specificity by green galvanic displacement. The Si nanograss arrays are directly grown on a Si substrate via catalyst-assisted vapor–liquid–solid (VLS) growth and subsequent plasma interaction. AgNPs were rapidly immobilized on Si nanograss arrays without any organic reagents, and avoiding the interference signal of additives. The AgNPs decorated 3D bionic silicon nanograss arrays not only possess a larger specific surface area (loading more reporter molecules), but also provide a potential distribution and arrangement for plentiful hot spots. Using Rhodamine 6G (R6G) as a probe molecule, the prepared SERS substrates exhibited great potential for high-sensitivity SERS sensing, and pushed the limit of detection (LOD) down to 0.1 pM. A higher Raman analytical enhancement factor (AEF, 3.3 × 107) was obtained, which was two magnitudes higher than our previous Ag micro–nano structures. Additionally, the practicality and reliability of our 3D bionic SERS substrates were confirmed by quantitative analysis of the spiked Sudan I in environmental water, with a wide linear range (from 10−10 M to 10−6 M) and low detection limit (0.1 nM).

In this work, three new coordination polymers with a free carboxyl group, [Zn4(HIDCPy)4(DMSO)(DMF)3]n (1), [Cu(HIDCPyO)(DMSO)]n (2), and {[Cd4(HIDCPy)6]·4DMF·4C2H8N·H2O}n (3) (H2IDCPy = 2-(pyridine...

With the rapid development of technology, information security has always been considered a major challenge. In this work, the excellent combination of persistent luminescence, photoluminescence, up-conversion luminescence, and thermo-luminescence in a particular material Zn4B6O13:Tb3+,Yb3+ synthesized via a solid-state reaction is reported, which can be used for the information encryption and anti-counterfeiting. Tb3+ ions were chosen as the emitting centers for multimodal emissions, and Yb3+ codoping can be used as electron traps and sensitizer to adjust trap distribution and efficient up-conversion luminescence in rare-earth-doped luminescent materials. Besides, the as-prepared luminescent materials exhibit high thermal stability and excellent water resistance. On the basis of these properties, the samples were used to print luminescent images through a screen printing process on the film and banknote. The luminescent image in a film is showing different patterns and on a banknote is showing green emissions under different stimulations. These multimodal emissions demonstrate that the as-prepared sample is suitable for advanced information encryption and anti-counterfeiting.

A new method was developed for quickly preparing a highemissivity silicon boride compound of SiBx (x = 3, 4, 5, 6) by highly exothermic Ti-TiO2-Si-Al chemical oven preheating. The SiBx combustion synthesis process and adiabatic combustion temperature were investigated. A large exothermic reaction occurred at the combustion temperature of 1 700 K. X-ray diffraction results indicate that an SiBx phase and a substantial amount of unreacted Si were identified in the products. By increasing the boron content until the Si-B ratio reached to 1 : 6, the diffraction peaks primarily indicated SiB6, SiB4, and Si11B33 in the final product. According to the spectra and quantitative results, the atomic chemical composition ratio of Si and B was close to the nominal composition. Thus, this method offers an efficient way to produce Si-B compounds with less time and energy consumption than current methods.

Tumor cells can activate platelets, which in turn facilitate tumor cell survival and dissemination. Platelets inhibition or blocking platelet-tumor cell interactions has become a strategy to suppress tumor progression. In this study, we investigated the effect of ticagrelor, a new antiplatelet drug, on tumor cell proliferation and metastasis. Our results show that ticagrelor not only inhibits the proliferation, migration, and invasion of B16F10 and Lewis lung carcinoma cells but also induces platelet apoptosis. In addition, we find that apoptosis of the platelet cells is dose dependent. Further, the result of in-vivo experiments proved that ticagrelor treatment decreased the tumor metastasis. The results of this study demonstrate that ticagrelor may be a potential anti-tumor agent for tumor metastasis.

The Eu2+/3+ mixed-valent complexes have aroused attention because of their potential application in the catalytic field endowed by the variable valence. Herein, we develop an ingenious green strate...

From the perspective of efficient and economical utilization of materials, it is very meaningful to achieve multifunctional performance in its assembly process, and this is also the future developm...

Accurate temperature measurement plays an important role in a variety of industrial processes and scientific researches. In our work, the dual-mode temperature response nanoprobe CDs-Tb-TMPDPA containing a two-photon ligand (4-(2,4,6-trimethoxyphenyl)-pyridine-2,6-dicarboxylic acid, TMPDPA) sensitized Tb3+ as a temperature-sensitive unit and carbon dots (CDs) as photothermal reagent and a fluorescence reference unit, have been designed and synthesized. In this system, both the fluorescence intensity ratio and the fluorescence lifetime have a good response to temperature. In addition, due to the excellent photothermal conversion capability of CDs, photothermal antibacterial ability was also tested. Based on the temperature dependence of the fluorescence and the two-photon excitation characteristics of CDs-Tb-TMPDPA, the nanoprobe can also be used in the anti-counterfeiting. Our finding opens a new prospect for the use of two-photon sensitized dual-mode fluorescence thermometers.

A passivation layer plays an important role in suppressing charge recombination on the surface trap states. However, the effect of a single passivation layer is limited. Building a passivation syst...

Elaborately designed glucose-responsive insulin-delivery systems are highly desirable for the treatment of diabetes because it can secrete insulin depending on blood glucose levels. Herein, mimic multi-enzyme metal-organic framework (MOF)-based (insulin and glucose oxidase-loaded cobalt-doped ZIF-8, abbreviated as Ins/GOx@Co-ZIF-8) stimuli-responsive microneedles (MNs) were designed for painless glucose-mediated transdermal administration. In this work, GOx and Co2+ ions were engineered into MOFs to construct a mimic multi-enzyme vehicle. GOx in the MOF, as the glucose-responsive factor, could catalyze glucose into gluconic acid with the formation of H2O2 as the byproduct. The gluconic acid formed decreases the local pH in MOFs, resulting in the degradation of MOFs and thus preloaded insulin would be released. Meanwhile, catalyzed by Co2+ ions in the MOF, the byproduct H2O2 was decomposed. Possible free Co2+ ions would be chelated by EDTA-SiO2 nanoparticles in MNs and removed by peeling MNs off. The as-obtained mimic multi-enzyme MOF-based MNs showed good dependence on glucose concentration without divulging H2O2 and Co2+ ions and enough stiffness to penetrate into skin. This study offers a new strategy, using facilely synthesized MOFs as depots to integrate with MNs, for designing stimuli-responsive transdermal drug-delivery systems.

Hydrogen polysulfide (H2Sn) has currently attracted much research interest because it not only plays an important physiological function in many biological and health-related events, but also is co...

One-pot reaction of an asymmetrical acylhydrazone ligand H3L with Ln(ClO4)3 and CuCl2 in MeOH and MeCN solvents resulted in two novel octanuclear complexes, [Cu4Dy4L4Cl6(CH3OH)8(H2O)4]·Cl2(CH3OH)9(H2O)3 (1) and [Cu4Tb4L4Cl6(CH3OH)2(H2O)10]·Cl2(H2O)x (2). Single-crystal X-ray diffraction studies revealed that these two complexes are isostructural and can be viewed as being built from two {Cu2Ln2L2} (Ln = Dy or Tb) butterfly-shaped units. Direct current magnetic susceptibilities and field-dependent magnetization measurements demonstrated the presence of strong ferromagnetic interaction between CuII and LnIII and magnetic anisotropy. Furthermore, alternating current (ac) magnetic measurements illustrated that these two complexes showed temperature- and frequency-dependent signals in the out-of-phase ac susceptibility under zero applied field, which are typical features of the slow relaxation of the magnetization for 1 and 2. The effective energy barrier (Ueff) for 1 was 54 K, which is one of the highest Ueff values yet reported for CuII/LnIII single-molecule magnets.

Using natural minerals seems to be one of the most novel and environmentally friendly strategies to design catalysts for CO2 conversion. Herein, we report a facile and efficient nano-catalyst for the synthesis of non-symmetric carbonate by utilizing a magnesium-aluminium silicate nano-mineral—attapulgite (ATP). Thanks to the unique structure of ATP and its ability to absorb carbon dioxide, the Ag/attapulgite nano-catalyst has excellent catalytic activity and stability in the carbon dioxide fixation reaction. The design of this Ag/attapulgite nano-catalyst provides a novel idea for realizing CO2 conversion and clay resource utilization.

A series of novel asymmetry 3d–4f helicates Zn3LnL4 (H2L = N-(2-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino)ethyl)-2-hydroxybenzamide, Ln = Dy(1), Gd(2), Er(3)) were successfully constructed via selective incorporation of groups with different coordination capabilities. These helicates with the well-defined conformation demonstrate high catalytic efficiency in converting CO2 to cyclic carbonates under mild conditions. Particularly, Zn3ErL4 showed superior catalytic performance with high catalytic activity (TOF up to 38 000 h−1) and extraordinary selectivity (up to 99%) across the wide substrate scope. Meanwhile, these 3d–4f helicates showed stable catalytic performance without being influenced by the moisture and air. The results presented herein highlight an important consideration for constructing heterometallic and asymmetric complexes for catalyzing CO2 conversion.

A series of tetranuclear lanthanide clusters supported by organic ligands ([Ln4L6(NO3)4]·4(MeCN), Ln = La, Nd, Sm) has been synthesized and characterized. The Lewis acidic Ln3+ sites were investigated as highly efficient catalysts regarding CO2 activation. The clusters showed significant thermal stability after 4 reaction cycles of CO2 insertion into epoxides to form cyclic carbonates, with TOF up to 6700 h−1. The catalytic system also displays a wide substrate scope and high catalytic activity. Unfortunately, the catalytic efficiency of the catalysts for some sterically hindered reaction substrates is not very satisfactory.

For the emerging potassium-ion energy storage technology, the major challenge is seeking suitable electrode materials with a robust structure and fast kinetics for the reversible insertion/desertion of potassium ions. Here, a pseudocapacitive core–shell heterostructure of titanium oxide/carbon confined into N, P, and S co-doped carbon (TiO2/C@NPSC) is obtained by pyrolyzing a metal–organic framework (MOF) precursor of MIL-125 (Ti) modified by poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) polymer. The distinctive structure of TiO2/C@NPSC can effectively buffer the volume variation of TiO2 nano-grains during the charge/discharge process, increase the electron/charge transfer, provide abundant active sites, and boost the pseudocapacitive-dominated K+-storage. Consequently, the TiO2/C@NPSC anode displays superior cyclability and fast kinetics behavior. Upon integrating it with a high capacitance activated carbon cathode derived from another MOF precursor, the as-built potassium-ion hybrid capacitor achieves a high-energy density of 114 W h kg−1 and a power output of 21 kW kg−1. Moreover, in a wide working potential window of 0–4.2 V, the device also maintains over 91.6% of its initial capacity after 10 000 cycles, showing a superior cycle stability. Our results are conducive to understanding the importance of anode-engineering for designing advanced PIHCs.

Monitoring and imaging glutathione (GSH) in living systems is an essential tool to determine the key roles of GSH in biological pathways, but most fluorescent sensors can only be used in vitro because of their potential biotoxicity. Here, a peptide-based fluorescent sensor, FP, has been successfully designed and synthesized based on the biocompatibility of the peptide backbone and low toxicity. The design strategy of FP contains a specific spatial structure of the peptide sequence which selectively binds to Cu2+, triggering fluorescence quenching. Interestingly, the fluorescence of FP can be fully restored by GSH, due to the strong binding between Cu2+ and the GSH sulfhydryl groups. Finally, the sensor is highly sensitive and selective for imaging GSH both in vitro and in vivo with low toxicity. Thus, FP with its strong "on-off-on" fluorescence changes is a powerful way to image GSH both in cells and zebrafish larvae to study the GSH pathway.

As a multifunctional signaling molecule, hydrogen sulfide (H2S) plays an essential role in diverse physiological and pathological processes. The two-photon fluorescence probes detecting H2S selectively in vivo could be useful tools to better study the mechanism of diseases. Then, an efficient two-photon lysosome-specific probe 1 has been developed to detect endogenous H2S in living cells and mice. Probe 1 displays excellent properties with 28-fold fluorescence enhancement, marked color changes in naked-eye and fluorescence, high selectivity and sensitivity, and low detection limit (0.22 μM) to H2S. These remarkable properties of probe 1 enable its practical applications in detecting H2S in environment (wastewater) and food (beer). Moreover, as a two-photon probe under near infrared excitation at 790 nm, probe 1 can monitor the level changes of endogenous H2S of lysosome and tumor in living system with good membrane permeability and high imaging resolution. Specially, the probe detecting H2S distribution in lysosome could provide more evidences to explain the association of target-organelle and H2S.

It is highly indispensable to detect Cu2+ and S2− because of its vital role in living organisms and the environment. In this work, a novel “on-off-on” coumarin-based colorimetric fluorescent probe L for sequential recognition of Cu2+ and S2– was strategically designed and synthesized. It displays low detection limit measured to be 2 × 10−8 M and 6 × 10−8 M respectively for Cu2+ and S2– with high selectivity and excellent sensitivity. In addition, an appropriate broad pH of 4–10 allows probe L to be applied to the biological window, and MTT experiments show that probe L has negligible cytotoxicity, which demonstrate it can be employed to determine Cu2+ and S2– in A375 cells.

Cerium oxide (CeO x) with a reversible surface Ce3+/Ce4+ redox pair has played an important role in catalytic reactions, whereas catalase mimetics of CeO x have attracted little attention in the field of biotherapy. Herein, a smart photosensitizer-cerium oxide nanoprobe was developed to represent a promising paradigm in high-performance photodynamic therapy. The photosensitizer was linked to CeO x nanoparticles through a substrate peptide (EGPLGVRGK) of matrix metalloproteinase-2 (MMP-2). The smart nanoprobe could be converted from the "silent state" before arriving at the cancer cells to the "activated state" within the cells to turn on the fluorescence and 1O2 generation when the peptide linker (EGPLGVRGK) was cut by the cancer biomarker MMP-2. Moreover, CeO x played the role of an excellent catalase-like compound to decompose endogenous hydrogen peroxide to relieve tumor hypoxia. Via the conventional application of CeO x, our study showed innovatively how a smart nanoprobe could relieve tumor hypoxia and achieve a therapeutic effect for highly selective and efficient personalized treatment.

Real-time temperature feedback in tissue based on photothermal therapy is an urgent problem to be solved in cancer treatment. Herein, a smart all-in-one nanoprobe THA@Eu-NMOF@Fe/TA was designed and assembled by postsynthetical functionalization of an Eu(III)-based nanoscale metal–organic framework (Eu-NMOF) with a two-photon-absorbing β-diketonate ligand 4,4,4-trifluoro-1-(9-hexylcarbazol-3-yl)-1,3-butanedione (HTHA) and Fe(III)/tannic acid assembly (Fe/TA). Such a functionalized material can simultaneously achieve the temperature-sensing and optical heating under a single beam of near-infrared (NIR) light. Under 808 nm laser excitation, real-time feedback of temperature by monitoring thermoresponsive fluorescence emission ratio (I616/I590) and fluorescence lifetime of Eu(III) ions were realized. Meantime, Fe/TA served as the photothermal agent and antibacterial agent to implement photothermal therapy (PTT) and antibacteria simultaneously. The functions of the nanoprobe were proved with ex vivo experiment...

Because of the potential integration the high energy density of lithium ion batteries and high power output of electrochemical capacitors, lithium ions hybrid capacitors (LIHCs) have been emerged as one of the promising electrochemical energy storage devices. Developing suitable battery-type anodes and capacitive-type cathodes are important to achieve high-performance LIHCs. Herein, we construct an orthorhombic niobium pentoxide/carbon (T-Nb2O5/C) nanocomposite with surface-driven lithium ion storage merit via a facile pyrolysis of Nb-based coordination-polymer. The synthesized T-Nb2O5/C exhibits higher capacity and a much better rate capability compared to commercial Nb2O5. At the same time, benefiting from the host-guest chemistry, we synthesize a high-capacitance N-doped porous carbon cathode through annealing the mixture of β-cyclodextrin and urea combined with a potassium hydroxide activation. As a consequence, an advanced LIHCs is built based on the above electrode materials, that delivers a high energy density (92 W h kg−1) and high power density (17.5 kW kg−1) within the wide potential window of 0–3.5 V. A superior cycling performance is also delivered by our device with 86% of the capacitance retention after 10 000 cycles at the 2 A g−1, successfully bridging the performance gap between conventional batteries and supercapacitors.

A novel reddish orange long persistent phosphorescence was observed in Na2CaSn2Ge3O12:Eu3+ and Na2CaSn2Ge3O12:Eu3+,Dy3+ phosphors which were prepared using conventional solid-state method at 1250 °C in air. X-ray diffraction analyses demonstrate that all samples consist of Na2CaSn2Ge3O12 as the predominant phase. With the excitation of 318 nm, all the samples can emit reddish orange light, which is attributed to the 5D0→7F1 transition of Eu3+. The Dy3+ as co-dopants greatly prolong the phosphorescent persistence time of Na2CaSn2Ge3O12:Eu3+ phosphor. The persistent time of the persistence is 5 h, remarkable increased by 21-fold after the co-doping of 0.4 mol% Dy3+. The significant changes in the thermoluminescence curves demonstrated that the incorporation of Dy3+ into Na2CaSn2Ge3O12:Eu3+ not only enriched the types of traps, but also greatly increased the concentration of original traps (V″Ca,V″Na. It can be seen from the photoluminescence, long persistent phosphorescence and thermoluminescence spectra of all obtained samples that the optimal composition is Na2CaSn2Ge3O12:1.2%Eu3+,0.4%Dy3+. The possible mechanism of the reddish orange long persistent phosphorescence phosphor Na2CaSn2Ge3O12:Eu3+,Dy3+ is investigated.

The integration of metal-organic frameworks (MOF) into organic polymers represents a direct and effective strategy for developing innovative composite materials that combine the exceptional properties of MOFs with the robustness of organic polymers. However, the preparation of MOF@polymer hybrid composites requires an efficient dispersion and interaction of MOF particles with polymer matrices, which remains a significant challenge. In this work, a new simple and direct approach was applied for the development of Ln-MOF@polymer materials. A series of Ln-MOF@TGIC composites {Ln-MOF = [Ln(μ3-BTC)(H2O)6]n (Ln-BTC), where Ln = Eu, Tb, Eu0.05Tb0.95; H3BTC = 1,3,5-benzenetricarboxylic acid; TGIC = triglycidyl isocyanurate} were successfully obtained by applying a grinding method via the chemical bonding between uncoordinated carboxylate groups in Ln-BTC and epoxy groups in TGIC. The Ln-BTC@TGIC materials possess significant fluorescence characteristics with superior emission lifetimes and quantum yields if compared to parent Ln-MOFs. Interestingly, under the UV irradiation, a considerable color change from yellow in Eu0.05Tb0.95-BTC to red in Eu0.05Tb0.95-BTC@TGIC was observed. The energy-transfer mechanism was also rationalized by the density functional theory (DFT) calculations. The developed Ln-BTC@TGIC composites were further applied as functional fluorescent coatings for the fabrication, via a simple spraying method, of the flexible polyimide (PI) films, Ln-BTC@TGIC@PI. Thus, the present work unveils a new methodology and expands its applicability for the design and assembly of stable, multicomponent, and soft polymer materials with remarkable fluorescence properties.

Uniform water soluble MoS2 quantum dots (WS-MSQDs) are synthesized via a sequential combination of sintering/etching/exfoliation method and solvothermal route. The obtained WS-MSQDs with average size of approximately 3.4 nm exhibit sufficient water solubility and remarkable fluorescence properties. The WS-MSQDs have been utilized as a probe for detection of Fe3+ ions with high selectivity and specificity. Furthermore, the WS-MSQDs exhibit high fluorescence stability under different conditions. Finally, the WS-MSQDs are successfully applied for the fluorescence imaging of Fe3+ in living cells, which exhibited practical potential for biomedical applications.

International audience; The characterization of the largest worldwide representative data set of apricot (Prunus armeniaca L.) germplasm was performed using molecular markers. Genetic diversity and structure of the cultivated apricot genetic resources were analyzed to decipher the history of diffusion of this species around the world. A common set of 25 microsatellite markers was used for genotyping a total of 890 apricot accessions in different collections from the center of origin to the more recent regions of apricot culture. Using a Bayesian model-based clustering approach, the apricot genotypes can be structured into five different genetic clusters (F-ST = 0.174), correlated with the geographical regions of origin of the accessions. Accessions from China and Central Asia were clustered together and exhibited the highest levels of diversity, confirming an origin in this region. A loss of genetic diversity was observed from the center of origin to both western and eastern zones of recent apricot culture. Altogether, our results revealed that apricot spread from China and Central Asia, defined as the center of origin, following three major diffusion routes with a decreasing gradient of genetic variation in each geographical group. The identification of specific alleles outside the center of origin confirmed the existence of different secondary apricot diversification centers. The present work provides more understanding of the worldwide history of apricot species diffusion as well as the field of conservation of the available genetic resources. Data have been used to define an apricot core collection based on molecular marker diversity which will be useful for further identification of genomic regions associated with commercially important horticultural traits through genome-wide association studies to sustain apricot breeding programs.

The development of quick and effective strategies for the removal of organic dyes and the detection of metal ions in aqueous solutions remains a challenge for protecting the public health and envir...

A supramolecular approach to distinguish Na+ from other biologically important metal ions was demonstrated. By designing ligands reasonably, Na+-selective bonding was achieved in the construction of homochiral alkaline-lanthanide heteronuclear helicates, which was further confirmed by mixed-metal self-assembly experiments and 1H-NMR spectra.

Lanthanide MOFs (Ln-MOFs), {[Ln2(L)2(H2O)2]·5H2O·6DMAC}n, [Ln||| = Eu(1) and Tb(2); H3L = 4,4'-(((5-carboxy-1,3-phenylene)bis(azanediyl))bis(carbonyl)) dibenzoic acid, DMAC = N,N'-dimethylacetamide], with a new topology type have been isolated. Single crystal X-ray diffraction indicates that complexes 1 and 2 are isostructural with binuclear [Eu2(COO)7]n secondary building units as 7-connected nodes and H3L ligands as 3-connected nodes and can be viewed as a (5,7)-connected 3D framework with a new topological point symbol of {32·44·54} {34·46·56·65}. Complexes 1 and 2 exhibit an excellent luminescence sensing response to inorganic ions Fe3+, Cr2O72-, MnO4- and 4-nitrophenol, with a low detection limit and high Ksv value. Interestingly, when the MnO4- ions are detected, the color of the solid sample is observed to change from yellow to brown, visually indicating luminescence induction, which makes the process of detecting MnO4- ions simpler and more practical. Moreover, by using time-resolved photoluminescence techniques, complex 1 can effectively eliminate background fluorescence interference during detection and improve detection accuracy. Solvent luminescence studies, pH stability and PXRD data indicate that complexes 1 and 2 can be used as excellent water-stable multi-response luminescent sensors for detecting a wide variety of toxic substances. In addition, the mechanism of selective detection is explained by the energy competition between the excitation of complexes 1 and 2 and the ultraviolet absorption of the responsive substance.

The thriving development of nanotechnology has greatly promoted the development of drug delivery systems (DDSs) in the past decades. However, most DDSs themselves cannot serve as diagnostic reagents and must be metabolized, by which they may become poisonous and even cause immune reactions. In this study, a novel self-delivery drug–drug system (SDDS) nanohybrid based on the coordination assembly of a photodynamic reagent, tetra-(4-carboxyphenyl)porphyrin (TCPP), and a chemotherapy reagent, cis-platinum, was designed and synthesized. The four carboxyl groups of TCPP can compete with the chloride ions of cis-platinum by coordination interactions, forming a TCPP-cis-platinum nanohybrid (PCNH) for the purpose of photodynamic/chemotherapeutic synergistic treatment with a combinational index of 0.28. Meanwhile, the PCNH system can effectively protect the photosensitizer TCPP from photobleaching when irradiated continuously in the photodynamic therapy (PDT) process, which is very crucial for PDT. Furthermore, introduction of the heavy atom platinum can greatly enhance the producing efficiency of 1O2 by 46%. In addition, the red emission fluorescence of TCPP is beneficial for monitoring and tracing the process of drug delivery when used in vitro. This work may pave a new way for the design of new integrated nanohybrids for diagnosis and synergistic treatment.

The therapeutic effects of chemotherapy and photodynamic therapy (PDT) are limited seriously by tumor hypoxia and low cell uptake capacity. Herein, a smart tumor-microenvironment (TME) responsive nanoprobe was developed using pH-responsive and decomposed CeOx/Fe2O3 as a carrier not only to strengthen cell uptake capacity, increase drug packaging efficiency and modulate tumor hypoxia, but also to act as an acceptor of Forster resonance energy transfer (FRET) and achieve energy quenching of an excited photosensitizer. Due to the urchin-like hollow structures of the CeOx/Fe2O3 carrier, the chemotherapy drug doxorubicin (DOX) and the photosensitizer chlorine e6 (Ce6) could be co-loaded to form the nanoprobe CeOx/Fe2O3-C&D. In normal tissue, the nanoprobe CeOx/Fe2O3-C&D showed weak cytotoxicity. Once in the TME, the CeOx/Fe2O3 nanoshells began to break up, DOX was released rapidly at the tumor site, and CeOx/Fe2O3 showed catalase-like activity to decompose endogenous H2O2 and produce O2 persistently to overcome hypoxia in situ. Meanwhile the Ce6 was transformed from a “silent state” to an “activated state”, generating the fluorescence signal and singlet oxygen (1O2) by weakening the FRET efficiency. Therefore, our study showcases an innovative strategy to enhance cell uptake capacity, adjust tumor hypoxia and achieve highly selective and specific combination therapy.

A stimuli-activatable theranostic system enabling selective imaging and controlled phototherapies is highly essential for precise cancer diagnosis and treatment. Herein, we designed a smart theranostic nanoprobe that comprised a photosensitizer (PS), gold nanorods (AuNRs) and a matrix metalloproteinase 2 (MMP2)-responsive peptide linker. Apart from being applied for photodynamic therapy (PDT), PS has also been widely used for fluorescence imaging. Spatiotemporal control of the photoactivity of PS is of great importance for cancer theranostics. In the present work, due to the presence of Forster resonance energy transfer (FRET) between PS and AuNRs, the fluorescence and 1O2 production of PS were suppressed during the circulation, avoiding adverse damage to normal tissues; however, the nanoprobe could be activated for targeted imaging and selective PDT when the peptide linker was cleaved by overexpressed MMP2 in cancer cells. More importantly, the restored fluorescence could be successfully used to quantitatively detect MMP2 with a detection limit of 29 pM and to light up cancer cells, further guiding synergistically activated PDT/PTT (photothermal therapy) for highly efficient and special killing of cancer cells. This study can help design smart cancer-related biomarker-activatable theranostic probes for molecular sensing and site-specific cancer treatment.

A series of novel hexanuclear 3d-4f complexes formulated as {[Ln2Zn4(μ3-OH)2L4(AcO)2(NO3)2(DMF)2]·2(CH3OH), LnIII = Dy3+ (1), Nd3+ (2), Tb3+ (3)} have been synthesized and characterized. These complexes 1-3 show excellent catalytic performance for the cycloaddition of CO2 and epoxides to obtain cyclic carbonates. The catalytic system has a wide substrate scope with high turnover numbers (9700) and high turnover frequencies (808 h-1) under mild conditions. Additionally, the catalysts could be conveniently prepared on a large scale and recycled.

Due to the good biological properties of coumarinocoumarin and the importance of cysteine (Cys) in organisms, a novel coumarinocoumarin-based probe (CCx) has been designed and synthesized for detecting intracellular Cys. CCx was prepared as a latent fluorescence probe from salicylaldehyde using a simple 3-step procedure to achieve a large Stokes shift (90 nm), high sensitivity (LOD 388 nM) and a fluorescent turn-on response (F/F0 = 15) towards Cys. Owing to the specific conjugate addition-cyclization reaction between Cys and an acrylate moiety, CCx displayed high selectivity toward Cys over other various natural amino acids under physiological conditions. Then, CCx was successfully used for the fluorescence imaging of Cys in HeLa cells, and a rapid response was observed after incubation with CCx for 5 min. Furthermore, two-photon fluorescence images of mice tumor tissues were obtained, and the viability was measured to be more than 80%, which shows that CCx can be used as a rapid and biocompatible probe for Cys in vivo.

A highly selective ratiometric ESIPT fluorescent probe has been designed for the detection of palladium species of all the typical oxidation states (0, +2, +4). The probe exhibits a ratiometric fluorescence response towards the palladium species in about 20 min at room temperature based on the excited state intramolecular proton transfer (ESIPT) process. Moreover, the probe can discriminate different palladium species (Pd0, Pd2+, Pd4+) under different detection conditions. Furthermore, the probe can be used to quantitatively detect palladium in drinking water with a low detection limit (15.6 nM, 1.66 ppb). Additionally, it could be used as a two-photon palladium probe for bioimaging with low cytotoxicity and autofluorescence.

The ability to rapidly, sensitively, and selectively detect ascorbic acid (AA) is important for medical assays and diagnoses. Here, a new cobalt oxyhydroxide (CoOOH)-functionalized up-conversion nanoparticle (UCNP) system was designed for the detection of AA. For the UCNPs, ligand-free β-NaYF4:Gd/Yb/Tm/Ho@NaYF4 offered simultaneous blue and red light emission, but CoOOH on the UCNP surface acted as a quencher that could effectively absorb the 475 nm-wavelength light produced by the luminescence of the nanoparticles. This quenching was found to be easily eliminated by the addition of AA through the FRET process. The ratio of the intensity of the up-conversion luminescence at 475 nm to that at 654 nm showed an excellent linear correlation with the concentration of AA. The nanoprobe also exhibited excellent accuracy in the quantitative analysis of AA in diluted fetal bovine serum. In addition, the probe showed an ability to be used for imaging AA in living cells, and may thus be considered as a good candidate for use in clinical diagnosis and drug screening.

Lysosomal pH is known to be acidic, which plays a vital role in various processes in living organisms. Frequency upconversion luminescence exhibits the unique ability to convert low energy photons into high energy photons, which can be used in live samples due to its deep penetration, low tissue damage, etc. The development of sensitive frequency upconversion probes with a low pKa, high sensitivity, and specific selectivity for lysosomal pH detection is of great importance. Herein, we report a novel frequency upconversion luminescence probe, NRH-Lyso, by conjugating the rhodamine derivative NRH and the lysosome targeting functional group 4-(2-aminoethyl)morpholine. NRH-Lyso shows a sensitive response to acidic pH and excellent selectivity in the presence of metal ions, anions, and small molecules. Due to the structural transformation of lactam ring opening and closing of NRH-Lyso, the probe shows an almost 80-fold enhancement in emission intensity when the pH changes from 7.0 to 4.0 under 808 nm laser excitation. The living cell imaging data reveals that NRH-Lyso can selectively detect lysosomal pH changes with excellent photostability and low cytotoxicity. All these features make NRH-Lyso a good candidate to investigate the lysosomal pH-associated physiological and pathological processes.

Although biothiols, including cysteine (Cys), glutathione (GSH), and homocysteine (Hcy) can be used to diagnose many diseases and research physiological metabolism in many physiological processes, in situ real-time detection and differentiation of biothiols is still challenging because their similar chemical properties and molecular structures. Herein, we utilized the native chemical ligation (NCL) reaction mechanism to develop a Forster resonance energy transfer (FRET) strategy for designing a cell penetration peptide TAT-modified ratiometric two-photon biothiols probe (TAT-probe). The TAT-probe can not only rapidly enter into mitochondria assisted by TAT peptide, but also simultaneously detect biothiols and sequentially distinguish GSH. When the TAT-probe was excited with 404/820 nm wavelength light, it showed a change in the ratio of fluorescence after adding biothiols, including a quenched red fluorescence intensity (λem = 585 nm) and an enhanced signal in green fluorescence intensity (λem = 520 nm). Excitingly, the TAT-probe excited at 545 nm could display a red fluorescence (λem = 585 nm) towards GSH and a quenched signal towards Hcy or Cys. This specific fluorescence response indicated the TAT-probe could effectively detect biothiols and differentiate GSH from Cys/Hcy in mitochondria. This work pioneered a new approach to design and synthesize biothiol-probes based on peptides and NCL reaction mechanism.

BF3 is an important catalyst in organic synthesis and petrochemicals which widely used in many chemical reactions. However, minor leaks may lead to serious environmental pollution and deadly biological damage. Therefore, how to quickly discover BF3 with high selectivity and sensitivity is of great significance and challenge. Here, we designed a BF3 specific fluorescent probe on the Rhodamine's switch ring process. In the presence of BF3, the fluorescence intensity showed a remarkable increase (200-fold) and the color of probe changed obviously with quick respond (

Molecular robot provides a promising way to receive response signals and make decisions with intelligent information processing at the molecule level. In this work, a molecular robot prototype based on a europium(III)-cyclen complex (EuL) was designed and assembled, consisting of multiplex sensing and information processing in a single system. By utilizing the Eu3+ ion as a central processing unit (CPU) and terpyridine (Terpy) group as an arm of the molecular robot, multiplex detection function of this molecular robot can be accomplished in three test channels: the detection of Fe2+ with UV-vis, Zn2+ using photoluminescence, and Mn2+ using magnetic resonance imaging. The optimized structures revealed that the transition metal ions bound by the arms of two EuL molecules formed a hexacoordination octahedral rigidity structure in the adducts. For the structure of L and EuL, three pyridine rings of Terpy unit were not in a plane, and they were fixed to form a plane when captured the transition metal ions during the formation of the adducts. In addition, three different modes of molecular logic devices (OR, INHIBIT, and YES) were established based on relevant signals in the multiplex detection channels. The sensing of metal ions in human urine using EuL was also carried out, and the result demonstrated the presence of good recoveries and high analytical precision. Such a molecular robot prototype is expected to be used in intelligent medical diagnostics and, in particular, information processing at molecular level.