Controlling heavy metal ions is crucial, as prolonged exposure to Cu2+ can cause neurodegenerative diseases and severe organ damage. To address this global issue, we have developed two anionic lanthanide-based metal-organic frameworks (Ln-MOFs), designated as University of Macau-1 (UM-1) and University of Macau-2 (UM-2), with porous structures. The synthesized UM-1 and UM-2 exhibit high specificity in recognizing and adsorbing Cu2+ ions. To expand the application of Cu2+ monitoring, a dual-mode rapid detection method integrating fluorescence and colorimetric techniques has been developed. In fluorescence, both Ln-MOFs exhibited high sensitivity with detection limits of 0.34 μM for UM-1 and 0.56 μM for UM-2. Then, a smartphone-assisted method was established for on-site colorimetric detection of Cu2+. Additionally, UM-1 and UM-2 achieved good removal efficiencies of 77.4% and 80.7%, respectively, in 30 min, when the concentration of Cu2+ was elevated to 25 mM. In conclusion, the porous anionic Ln-MOF showcases remarkable capabilities in the detection, separation, and removal of Cu2+. This innovative work not only provides an invaluable reference but also offers an effective solution for tackling the pressing issue of heavy metal pollution.

Direct separation of lignin fromfully acidic deep eutectic solvent(DES) is challenging because of its high viscosity and acidity. Inthis study, three synthesized DES-resistant polyimides (PIs), namely,B-PI, 6F-PI, and P-PI based on 4 & PRIME;,6-diamidino-2-phenylindole(DAPI) with 4,4 & PRIME;-(4,4 & PRIME;-isopropylidenediphenoxy)bis-(phthalicanhydride) (BPADA), 4,4 & PRIME;-(hexafluoroisopropylidene)diphthalicanhydride (6FDA) and pyromellitic dianhydride (PMDA), respectively,were used to prepare ultrafiltration (UF) membranes for the directseparation of sodium lignosulfonate (LS) from its DES (choline chloride:lacticacid) solutions for the first time. The morphology, pore size, surfaceproperty, degree of swelling, LS separation performance, and long-termstability of the resulting UF membranes were investigated in detail.The average pore sizes were in the range of 3.60-5.06 nm, andthe LS rejections, as well as the DES fluxes, were 44.0-66.4%and 4.71-16.55 L & BULL;m(-2) h(-1), respectively, both higher than those from commercial ZrO2/TiO2 membrane (25.6% and 1.91 L & BULL;m(-2) h(-1)). Among them, the B-PI membrane had the bestseparation performance and excellent operating stability for 20 hdue to its low fractional free volume and poor affinity with DES.Swelling and positive charges of membrane surface in the DES systemdecreased LS rejection. In addition, a higher degree of swelling andaffinity with DES led to an increased DES flux when compared withthe aqueous system. Herein the PI-based UF membranes are promisingfor the direct lignin separation process, especially in an acidicDES system.

The correlations between the molecular structures of four Tro''ger's base (TB)-based polyimides (PIs) and two non-TB containing analogues and physical properties including thermal conductivity (lambda) and dielectric properties both at low and high frequencies were investigated in detail. The TB-based PI films exhibited low dielectric constants (Dk = 2.25-2.80) at 10 GHz. They possessed much lower lambda values (0.035-0.145 W/mK) compared to the commercial PI Kapton (0.240 W/mK). The influences of incorporating TB units into chain backbones on aggregation structures and physical properties of PIs were identified. Incorporating TB units into chain backbones effectively reduced the degree of chain orientation and increased fractional free volume, leading to both low Dk and low lambda values for the resulting PI films. Also, introducing TB units enhanced molecular weights, toughness, and glass-transition temperature (Tg) of the resulting PIs. Therefore, the TB-based PIs can be promising heat-insulating and low-k dielectric materials.

Sulfonium salts are one of the most important class of organosulfur (IV) compounds which have a positive charge on the sulfur center with three C-S bonds. Because of their bench-stable, easy synthesis, broad structural diversity, and rich reactivity, sulfonium salts are playing a significant role in synthetic chemistry. In recent years, visible-light promoted photoredox catalysis is rapidly developing into a powerful tool for organic synthesis. In this paper, the recent advances of different sulfonium salts in the radical type reactions induced by visible light are summarized. The formation reactions of C-C bond and C-X (X=B, N, O, S, Se, Te, F, Cl, I) bonds are introduced, and the applicable scope and mechanism of some reactions are also discussed.

Agricultural products, such as foodstuffs and herbal medicines, may be contaminated by pesticides. Therefore, developing sensitive methods for pesticide detection are urgently needed for the assurance of food safety. In this study, a ratiometric fluorescent sensing system based on blue-emitted nitrogen-doped carbon quantum dots (N-CQDs) and red-emitted copper nanoclusters (CuNCs) complex was fabricated for pesticide detection. The selective detection of thiram and paraquat, two typical widely used pesticides, can be easily realized by changing the solvent environment. The detection limit can be reached as low as 7.49 nM and 3.03 nM, respectively. A good linear correlation was found over the concentration range from 10 to 500 nM for thiram and 5 to 100 nM for paraquat. More interestingly, fast and visual detection of thiram and paraquat can be achieved via smartphonebased colorimetric analysis, which has provided an effective implementation for on-site monitoring of the levels of pesticide residues in food.

Fluorination in enhancing photoactivated antibacterial activity of Ru(ii) complexes with photo-labile ligands was studied. Ru(ii) polypyridine complexes containing a di-fluorinated dppz (dipyrido[3,2-a:2 ',3 '-c]phenazine) or mono-trifluoromethylated dppz bidentate ligand and four pyridine monodentate ligands (complexes3and4) were found to show potent photoactivated antibacterial activity against methicillin-resistantStaphylococcus aureus(MRSA), vancomycin-resistantEnterococcus(VRE), andEscherichia coli(E. coli) in both normoxic and hypoxic conditions. The bactericidal effect of complexes3and4under hypoxic conditions may stem from the fluorine-containing Ru(ii) aqua species after photo-induced pyridine dissociation, and DNA may be the potential antibacterial target. Photosensitized singlet oxygen may also account for their antibacterial activity under normoxic conditions. Moreover, negligible hemolysis rates as well as low dark- and photo-cytotoxicity toward human normal liver cells (L-O2) were also observed for both complexes. Our work may provide new insights into the development of novel and efficient Ru(ii) complex based photoactivatable antibacterial agents against antibiotic-resistant bacteria.

We demonstrated strong fluorescence blinking on large all-inorganic perovskite (CsPbBr3) nano-spheres. By performing (time-resolved) micro-photoluminescence (μ-PL) measurements, the unique blinking characteristics of the as-grown nano-spheres with diameters of hundred nanometers, are clearly observed. Blinking has no obvious on/off states, which is different from the blinking characteristics of quantum dots. It is believed that the blinking of fluorescence is caused by metastable defect-induced trapping of carriers on the surface of the nano-spheres, because dramatically suppressed fluorescence blinking and the decay rates of ultrafast carriers are realized by surface passivation of the nano-spheres. Surface defects are closely related to the ambient atmosphere, which has been further confirmed by PL measurements of the as-grown nano-spheres in vacuum. Additionally, we also found that the fluorescence blinking was significantly suppressed as the sample size increased, which can be attributed to the large-size induced average effect on fluorescence blinking. These results may be important for understanding the mechanism of the fluorescence blinking of perovskite materials and for developing optical devices with good fluorescence stability.

Single perovskite alloy nanowire capable of emitting lasing broadly and continuously is highly desirable for the miniaturization and integration of all-photonic devices. However, due to the limitation of a soft and dynamic crystal lattice and the synthesized strategy, single perovskite nanowire with single-band lasing emission is mostly observed. Here, we propose a solid-solid anion-diffusion process to construct single CsPbCl3-3xBr3x perovskite alloy nanowire with a widely tunable bandgap from 2.41 to 2.82 eV and a regularly geometrical structure. We realized a broadly and continuously tunable nanolaser from 480 to 525 nm in single CsPbCl3-3xBr3x nanowire, as different spots along the length serve as a gain medium and microcavity simultaneously. The kinetics and atomic-scale mechanism of solid-solid anion diffusion were analyzed by a quantitative study and theoretical calculations, giving a small activation energy of halide migrations. The dynamics of carrier transportations revealed the energy transfer in single CsPbCl3-3xBr3x alloy nanowire, that's why broadly tunable lasers are difficult to realize in single isolated nanowire. Our work proposes a new strategy to construct single perovskite alloy nanowire for achieving a broadly and continuously tunable laser, clarifies the mechanism and kinetics of anion diffusion in perovskite alloy nanowires.

All-inorganic lead halide perovskites are ideal platforms to investigate the fundamental physics of the light–matter interactions, due to their strong oscillator strength at room temperature and va...

Lithium is an important strategic resource and the Qinghai-Tibet Plateau possesses abundant liquid lithium resources in the salt lakes. Nanofiltration is a promising technique for lithium extraction from salt-lake brines. However, no information on the environmental impact of lithium nanofiltration extraction is available. This study used life cycle assessment (LCA), life cycle cost (LCC) and water consumption (LCWC) methods to evaluate the environmental burden of lithium nanofiltration extraction technique with the functional unit of 1 kg Li2CO3 products. The results showed that nanofiltration stage was the key process to produce the environment burden based on higher values of global warming potential, acidification potential, photochemical ozone creation potential, soot & ashes, and nutrient enrichment in comparison with the other stages of lithium extraction. Electricity consumption was the major contributor to global warming potential. The total life cycle cost was 18.01 USD with internal cost accounting for 99.99%. Direct water consumption was 22 times higher than indirect water consumption in this process. The water and energy consumption of nanofiltration stage accounted for 98.05% and 53.95% of total consumption, respectively. The total cost of energy and water consumption for nanofiltration technique in different regions followed the order of Tibet>Inner Mongolia>Sinkiang>Qinghai. This study provided quantitative data and theoretical basis for lithium resource exploitation in the ecologically-fragile regions in the world. (C) 2020 Elsevier Ltd. All rights reserved.

We investigated the optical properties of hybrid exciton–plasmon coupling ensembles composed of ZnSe/ZnS quantum dots and Ag nanoparticles in aqueous solution. We modulated their average interval by changing the ratio of quantum dots and Ag nanoparticles. The transition from dramatic PL enhancement to PL quenching state was experimentally observed, according to the continuous decrease of the PL lifetime. The PL enhancement rate exceeded 10, with the Purcell factor of 3.5. Meanwhile, the proportion of fast decay increased from 0.3 to 0.6, corresponding to the proportion of slow decay decreased from 0.7 to 0.4. Our experiment is important for the hybrid exciton–plasmon coupling system to be practicable in optoelectronic application.

Photoacid generators (PAGs) are finding increasing applications in spatial and temporal modulation of biological events in vitro and in vivo. In these applications, large pH jumps at low PAG concentrations are of great importance to achieve maximal expected manipulation but minimal unwanted interference. To this end, both high photoacid quantum yield and capacity are essential, where the capacity refers to the proton number that a PAG molecule can release. Up to now, most PAGs only produce one proton for each molecule. In this work, the hydrolysis reaction of benzyl chlorides was successfully leveraged to develop a novel type of PAG. Upon visible light irradiation, Ru(ii) polypyridyl complexes modified with chloromethyl groups can undergo full hydrolysis with photoacid quantum yield as high as 0.6. Depending on the number of the chloromethyl groups, the examined Ru(ii) complexes can release multiple protons per molecule, leading to large pH jumps at very low PAG concentrations, a feature particularly favorable for bio-related applications.

Ru(ii) polypyridyl complexes which can undergo photo-induced ligand dissociation and DNA covalent binding are considered as potential photoactivated chemotherapeutic (PACT) agents. Herein four pyridine-2-sulfonate (py-SO3-) ligand based Ru(ii) complexes [Ru(N-N)2(py-SO3)]+ (1-4) were synthesized and studied. All the complexes can undergo fast py-SO3- ligand dissociation and DNA covalent binding upon visible light irradiation. However, only complex 4 exhibited high photo-induced anticancer activities towards a series of cancer cells, with half maximal inhibitory concentration (IC50) values in 100-300 nM regions and phototoxicity index (PI) values of about 100. In particular, complex 4 can also kill cisplatin resistant SKOV-3 and A549 cancer cells with IC50 values in 200-400 nM regions and PI values of about 50, which should be the first report of Ru(ii) based PACT agents that are also effective towards cisplatin resistant cancer cells. Complex 4 exhibited much higher cell uptake and nuclear accumulation levels, which may be the main reasons for its high anticancer activities. The in vivo anticancer experiments indicated that complex 4 can inhibit tumor growth significantly with fewer side effects. Our results may provide guidelines for developing novel photoactivatable Ru(ii) anticancer agents.

Ru(ii) polypyridine complexes which can undergo photo-induced ligand dissociation and subsequent DNA covalent binding may potentially serve as photoactivated chemotherapeutic (PACT) agents. In this paper, three fluorinated dppz ligand coordinated Ru(ii) complexes (2-4) containing four monodentate pyridine ligands were studied. All complexes released one pyridine and covalently bound to DNA upon 470 nm irradiation. Compared with the parent complex [Ru(dppz)(py)4]2+ (1), 2-4 displayed enhanced phototoxicity but diminished dark cytotoxicity, more favorable for PACT application. Complex 3 is the most efficient one with IC50 values of about 8 μM toward HeLa and SKOV-3 cell lines, and also has a much higher IC50 value toward normal L-02 cells. Our results indicate that fluorination on the retaining ligand may be an efficient way to improve the drug activity of Ru(ii) PACT agents.

Three chloromethyl-modified Ru(ii) complexes were designed and synthesized as mitochondria targeting photosensitizers, which can generate carbon radicals in the presence of NADH under visible light irradiation, cause DNA cleavage and covalent binding in Ar-saturated solutions, and lead to apoptosis of human ovarian carcinoma SKOV-3 cells under hypoxic conditions (3% O2), demonstrating a new mode of type I mechanism to overcome the limitation of hypoxia in photodynamic therapy (PDT).

To guarantee the long-term stability of an orthopaedic implant, non-degradable surface coatings with the ability to selectively release bioactive drugs or ions are especially desirable. In this study, SrO-TiO2 composite coatings were deposited on the surface of Ti alloys, whose release behavior of bioactive Sr ions was modulated by the Sr configurations, either interstitial atoms in solid solution (TiySr2-2yO2) or strontium titanate (SrTiO3). A perfect linear relationship between the amount of the released Sr ions and the Sr content in the coating was observed. Among the SrO-doped TiO2 coatings, the 20% SrO-TiO2 coating where Sr existed in both forms of TiySr2-2yO2 and SrTiO3 not only promoted proliferation of bone cells but also enhanced their osteogenic differentiation, which was proved to be related to its Sr release behavior. However, overdosing with 30% SrO only resulted in one single Sr configuration (SrTiO3) and an inferior osteogenic function. This study suggests that Sr configurations of both interstitial atoms of the solid solution and SrTiO3 can realize the selective release of Sr, but they possibly have different effects on the biological functions and other properties including corrosion resistance.

Studies on quantum dots (QDs) provide great opportunities in single photon detection as well as single circular polarized photon emission, which are the key technology for future quantum information processing. For single photon detection, the quantum-dot-resonant-tunneling-diode (QD-RTD) is evaluated as one of the most promising scheme but still suffering from the ultralow working temperature (～5 K) and lack the capability to discriminate photon numbers. Here we demonstrate a photon-number-resolving detector based on quantum dot coupled resonant tunneling diodes (QD-cRTD). Individual QDs coupled closely with adjacent quantum well (QW) of resonant tunneling diode operate as photon-gated switches which turn on (off) the RTD tunneling current when they trap photon-generated holes (recombine with injected electrons). With proper decision regions defined, 1-photon and 2-photon states are resolved in 4.2 K with excellent propabilities of accuracy of 90% and 98% respectively. Further, by identifying step-like photon responses, the photon-number-resolving capability is sustained to 77 K, making the detector a promising candidate for advanced quantum information applications where photon-number-states should be accurately distinguished. On the other hand, we firstly performed the magneto-optical studies on single InGaAs/GaAs self-assembled QDs. We observed the exciton Zeeman splitting and diamagnetic shift of a single QD under magnetic field, and the exciton g factor and diamagnetic coefficient was extracted by fitting the magnetic field dependent PL energies. By comparing with theories, we discussed on the effect of QD size, shape and composition on these two parameters. Based on these work, we investigated the single QD exciton-cavity mode coupling effect under external magnetic field. By first time we observed the interaction of Zeeman splitted exciton spin states with the cavity mode and realized the selective enhancement of the SE rate of the exciton state with specific spin configuration by means of magnetic manipulation of Purcell effect. In this sense, single QD emission with higher circular polarization degree under non-polarized excitation was realized. Our results have high potential to open up a way to novel quantum light sources and quantum information processing applications based on cavity quantum electrodynamics effects.

Surface micro/nanotopography of orthopedic implants plays a significant role in determining their biological performance. In this study, plasma jet was for the first time utilized to modulate the micro/nanostructure of the plasma-sprayed 50% Nb2O5-TiO2 coating on the biomedical Ti alloy based on its high temperature and super-high cooling rate characteristics. Results show that the plasma jet can modulate the shape, dimension and distribution of the surface grains in a process-parameter-dependent manner, thus being able to tailor the micro/nanotopography of the surface coating. In vitro cell culture experiments proved that the plasma jet-induced topographical changes have great effects on the osteogenic activity of the MC3T3-E1 cells cultured on the coating surface.

Two dimensional (2D) semiconductor materials of transition-metal dichalcogenides (TMDCs) manifest many peculiar physical phenomena in the light-matter interaction. Due to their ultrathin property, strong interaction with light and the robust excitons at room temperature, they provide a perfect platform for studying the physics of strong coupling in low dimension and at room temperature. Here we report the strong coupling between 2D semiconductor excitons and Tamm plasmon polaritons (TPPs). We observe a Rabi splitting of about 54 meV at room temperature by measuring the angle resolved differential reflectivity spectra and simulate the theoretical results by using the transfer matrix method. Our results will promote the realization of the TPP based ultrathin polariton devices at room temperature.