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Background: In recent years, environmental pollution and heavy metal pollution caused by rapid urbanization and industrialization have become increasingly serious. Among them, mercury (II) ion (Hg2+) is one of the highly toxic heavy metal ions, and its pollution comes from various natural resources and human activities. Therefore, people attach great importance to the development of analytical methods for effective analysis and sensitive detection of Hg2+. Objective: Using grape skin as a green and environment friendly carbon source to synthesize fluorescent carbon dots and to apply them in detecting the concentration of Hg2+ in water. Methods: Using "Hutai No. 8" grape skin as a carbon source, fluorescent carbon dots were synthesized by a one-step hydrothermal method. The structure and fluorescent properties of the carbon dots were tested using TEM, XPS, XRD, and other characterization instruments, and their utilization on the detection of mercury ions in the actual water samples was explored. Results: The CDs had a particle size of about 4.8 nm and a spherical shape. There were N-H, C-N, C=O, and other functional groups on the surface. It was found that Hg2+ has an obvious fluorescence quenching effect on CDs, and thus CDs fluorescence quenching method to detect the concentration Hg2+ was established, and the detection limit was 3.7 μM, which could be applied to test the concentration of Hg2+ in water samples. Conclusion: Using grape skin as a carbon source, fluorescent carbon dots were successfully synthesized by the hydrothermal method. Carbon dots were used to detect mercury ions in water, and a method for detecting mercury ions in actual water samples was established.

An experimental study of biodegradation of Shenmu coal was carried out by using Ochrobactrum cytisi, Novospingobium naphthalenivorans, Alcaligenes faecalis and Pseudomonas fluorescens. The micro-nano pore structure of coal samples before and after biodegradation was studied by low-temperature N2 adsorption. For biodegraded coal, the results showed that micropores and mesopores are primarily open pores with good connectivity, including parallel plate pores and cylinder pores with two open ends; the specific surface area of biodegraded coal decreased from 2.2174 m2/g to 1.6255˜2.0537 m2/g, and the pore size of the coal biodegraded by the four bacteria decreased following biodegradation from 250 nm to 170˜200 nm, which may be due to collapse of the coal structure due to the bacterial degradation. Coal biodegradation by the dominant bacterium P. fluorescens led to a diminished mesopore size and an increased number of smaller mesopores, with the smaller mesopores gradually taking on dominant roles.

Two efficient probes were presented for dual channel simultaneous distinguishing detection of ClO− and Cu2+. Strong color changes and fluorescent emissions driven by ClO− induce irreversible oxidat...

Adding surfactants is an effective method to improve the biodegradation rate of coal. In this study, the action modes of nonionic Triton X-100, anionic surfactant SDS and cationic surfactant DTAB on the biodegradation of Xinjiang Wudong low-rank coal by Pseudomonas aeruginosa were investigated. By measuring cell membrane permeability and cell surface hydrophobicity of Pseudomonas aeruginosa, it was found that the permeability of cell membrane was enhanced under the action of Triton X-100, and reached the highest at 4 CMC, while SDS and DTAB inhibited the permeability of cell membrane. Cell surface hydrophobicity increased under the influence of Triton X-100, SDS and DTAB and reached a maximum at CMC. According to the effects of surfactants on the degradation rates of coal, it was shown that the improvement of cell membrane permeability could promote the degradation of coal, but the increase of cell surface hydrophobicity could inhibit the degradation of coal. When Triton X-100, SDS and DTAB were all at their optimal concentrations for the growths of Pseudomonas aeruginosa, the coal biodegradation rates reached 78.63 %, 55.93 % and 20.93 %, respectively. The adsorption experiment of bacteria on the coal surface and the low-temperature nitrogen adsorption experiment of coal presented that the improvement of permeability of cell membrane was the main factor for Triton X-100 to improve the coal degradation rate, even if it can slightly increase cell surface hydrophobicity. For SDS and DTAB, the decrease of cell membrane permeability and the increase of cell surface hydrophobicity are all not conducive to the biodegradation of coal.

A novel nitrogen doped and surface functionalized fluorescent CDs (T1) was synthesized by one-step and green hydrothermal method, which exhibits a satisfactory fluorescence quantum yield and a series of admirable features such as good aqueous solubility, narrow particle size distribution, resistance to photobleaching as well as excitation-dependent behavior. Benefitting from above merits, T1 can be employed to serve as an outstanding sensing platform for sensitive and accurate detection of ClO

A new acylhydrazone (C12H12N4OS, HL) and its three transition metal complexes [M(HL)2](NO3)2 (M = Co, I; Cu, II; Zn, III) have been synthesized. The structures of above four compounds were determin...

Carbon dots (CDs) synthesized from natural products received considerable attention due to their unique properties. In this work, CDs were synthesized using Luochuan Red Fuji apple peels as carbon source (Ap-CDs) by direct hydrothermal reaction, and were characterized by Transmission Electron Microscope (TEM), X-ray Diffraction (XRD), Raman spectra, Fourier-transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Ultraviolet and visible (UV-Vis) absorption spectra and Fluorescence (FL) spectroscopy. The effect of reaction temperature, reaction time and the amount of carbon source used on the fluorescent intensity of Ap-CDs was studied. Fluorescent properties measurement indicated that when irradiated by ultraviolet at the wavelength of 350[Formula: see text]nm, the Ap-CDs give out bright blue emitting at the maximum wavelength of 433[Formula: see text]nm with quantum yield of 9.43%. Meanwhile, it was found that the fluorescent intensity of Ap-CDs could be selectively quenched by Fe[Formula: see text] ions. The fluorescent quenching of Ap-CDs was linearly related to the concentration of Fe[Formula: see text] ion in the range of 0.05–300[Formula: see text][Formula: see text]M with the detection limit of 1.56[Formula: see text][Formula: see text]M. Accordingly, the concentration of Fe[Formula: see text] ion in the tap water and pork liver samples were tried to be measured by the fluorescent quenching Ap-CDs.

2-acetylpyridine-4-chloropyridine-2‑carbonyl hydrazone (C

The carbon nanomaterial based fluorescent probes have been widely applied in biological imaging. In the current research, we propose an interesting strategy for selective sensing of hypochlorite (ClO

Novel six-coordinated octahedral Co(II) complex [C36H26Br2CoN7O5, 1] and Cr(III) complex [C36H26Br2CrN6O2, 2] were prepared by the chelation reaction of the ligand 4-methoxybenzaldehyde-6-bromo-2-naphthoyl acylhydrazone and 2-acetylpyridine with Co(NO3)2·6H2O or CrCl3·6H2O in ethanol, and it is interesting that the coordination organic group wasn't the original acylhydrazone. Based on X-ray single crystal diffraction technique, the structures of 1 and 2 were characterized, which revealed 1 belonged to monoclinic system and P21/n space group, whereas 2 belonged to triclinic system and P 1 ¯ space group. The apparent activation energies of the thermal decomposition of 1 and 2 showed 1 had far better thermal stability than 2. Both of 1 and 2 quenched the intrinsic fluorescence of BSA through static processes, which suggested 1 and 2 could bind to BSA effectively and the non fluorescent ground state complexes were formed. UV–Vis spectra indicated each complex bound to ct-DNA by an intercalative mode. Microcalorimetry experiments illustrated the interactions of two complexes with BSA and ct-DNA were both spontaneous endothermic processes and the binding abilities of 1 with BSA and ct-DNA were greater than that of 2. The minimum inhibitory concentrations (MIC) of each complex against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa were all 50 μg·mL−1.

The biosolubilization experiments of Shenmu lignite were carried out by four kinds of bacteria, Ochrobactrum cytisi, Novospingobium naphthalenivorans, Alcaligenes faecalis, and Pseudomonas fluoresc...

Twelve-coordinated sulfate hydrogen bonding interactions in water-containing Fe(II) system, [Fe0.5(H2O)3]2SO4·H2O (1), are reported herein. The X-ray single-crystal structural characterization sugg...

8-Hydroxyquinoline-2-carbaldehyde-(4'-hydroxyphenylacetyl) hydrazine (HL) and Its complexes ([Cd(L)2·CH3CH2OH·8H2O] (1), [Cd(HL)2][CdCl4]·3CH3CH2OH·2H2O] (2) were synthesized from 8-hydroxyquinolin...

An experimental study of biodegradation of Shenmu coal was carried out by using

A salicylaldehyde-4-hydroxy phenyl acetyl acyl hydrazone (C15H14N2O3, HL) and its three complexes ([CuLPy]NO3 (1), [CuLCl(EtOH)] (2) and [CoL2]NO3·EtOH, (3)) were synthesized. The single crystal X-ray diffraction results of 1, 2 and 3 showed that the coordination atoms (N and O atoms) in the complexes exhibited four-coordinated pyramidal, five-coordinated and six-coordinated octahedral geometries centered on the metal ions, respectively. TG-DTG techniques illustrated that the maximum thermal decomposition peak temperatures of these compounds were all higher than 200 ℃, exhibiting strong thermal stabilities. All four compounds, HL, 1, 2 and 3, quenched the intrinsic fluorescence of BSA by means of static processes, as investigated by fluorescence spectra, which suggested that these compounds could effectively combine with BSA to form non-fluorescent ground state complexes. The UV–vis spectra showed that HL, 1, 2 and 3 effectively combined with CT-DNA through intercalative modes. Microcalorimetry tests indicated that the interaction processes of HL, 1 and 2 with BSA and CT-DNA were all spontaneously exothermic and entropy reducing, and each of the interaction durations was within 50 min. The interactions of the four compounds with BSA and CTDNA were also simulated by the molecular docking method, showing that the four compounds had hydrogen bonds and hydrophobic interactions with BSA and CT-DNA. The antibacterial activities of HL, 1, 2 and 3 against S. aureus, P. aeruginosa, B. subtilis and E. coli were determined, revealing that 1 and 2 exhibit stronger inhibition activities against P. aeruginosa than gentamicin sulfate. Complexes 1 and 2 are potential alternative drugs to gentamicin sulfate in the future.

The manganese chelate complex with MHA-H (the anion derived from the so-called methionine hydroxy-analogue, MHA) has been synthesized and characterized. The single-crystal structure (C10H18MnO6S2, ...

A novel rhodamine based 2-guanidinobenzimidazole functionalized probe RhoG was rationally designed and synthesized for the detection of tetravalent tin in environmental, geological, and biological samples with excellent selectivity, sensitivity, photostability and anti-interference performance. The mechanism investigation confirmed that guanidinobenzimidazole provided binding sites for Sn4+ and facilitate the formation of the complex. Successfully fluorescent imaging experiments in living L929 cells and MG-63 cells by confocal laser scanning microscopy presented a promising candidate for tracking tetravalent tin in biological organisms and processes thus contribute to significant breakthroughs in understanding the critically important functions of tetravalent tin.

A rhodamine based 2-aminobenzoxazole functionalized probe was presented for reversible detection of Fe3+ driven by the coordination of Fe3+ to 2-aminobenzoxazole that resulted in strong fluorescence emission and color change. Fluorescent imaging in living L929 and MG-63 cells offered a promising candidate for mapping Fe3+ in biological samples.

A series of novel and convenient fluorescent probes with unique acylhydrazone Schiff base functional moiety were designed and presented for sensing HClO in biological and environmental water samples with outstanding sensitivity, photostability and selectivity over other ROS/RNS, ions and biomolecules, through the irreversible HClO-promoted oxidation and hydrolyzation reaction in formation of the ring-opened product, fluorescein. The successful detection of HClO in swimming pool water and tap water samples, as well as cell imaging in living L929 and MG-63 cells, indicates that the probes not only help in the determination of the HClO concentration in practical water samples, but also serve as promising tools to exploit and elucidate the functions of HClO in biological cells, organisms and processes.

Two mononuclear complexes [Co(HL)L]NO3 (1) and [Cu(HL)2](NO3)2 (2)were synthesized from the reaction of 2-acetylpyridine-4-hydroxy phenylacetyl acylhydrazone (HL) with copper/cobalt nitrate hydrate. The single-crystal XRD results revealed the central Co and Cu ions in two complexes are both six-coordinated showing a distorted octahedral geometry. Thermal stabilities of 1, 2 and HL were explored by thermogravimetry (TG) and the apparent activation energy (Ea) followed the order 2 > 1 > HL. The interactions of 1, 2, HL with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) were investigated through UV–Vis absorption spectroscopy, fluorescence spectroscopy, microcalorimetry and molecular docking approach. From UV–Vis absorption spectroscopy and fluorescence spectroscopy results, it is shown that 1, 2 and HL can bind with CT-DNA by intercalation mode and quench the fluorescence of BSA through static process. The binding constants Kib of three compounds toward CT-DNA/BSA followed the order: 1 > 2 > HL. Thermogenic curves of three compounds interacting with CT-DNA and BSA were measured by microcalorimetry. The calculated enthalpies, entropies and Gibbs' free energy change (ΔH > 0, ΔS > 0, ΔG

A novel Cu(II) complex [Cu2L2(NO3)2] with 2-hydroxy-1-naphthaldehyde-(4’hydroxy)phenylacetyl hydrazone (C19H14N2O2·H2O, HL) was synthesized. The structure of [Cu2L2(NO3)2] was characterized by X-ray single-crystal diffraction and can be described as a distorted rectangular pyramid with binuclear coordination. IR, UV–vis and EPR spectra are used to discuss the structure of Cu(II) complex in different conditions. Magnetic properties were determined by EPR spectra and magnetic susceptibility studies, showing magnetic exchange interaction and weak antiferromagnetic exchange between two Cu(II) ions. The apparent activation energy (Ea) of thermal decomposition of compounds indicated that the thermal stability of [Cu2L2(NO3)2] is better than HL. The CT-DNA binding behavior of compounds was determined by UV–vis absorption and viscosity measurements and the results confirmed an intercalative binding mode with CT-DNA. Kb obtained was 6.24(±0.12) × 106 M−1 and 3.09(±0.006) × 106 M−1 for [Cu2L2(NO3)2] and HL, respectively, revealing that the binding ability of [Cu2L2(NO3)2] with CT-DNA was stronger. The thermogenic curves of compounds interacting with CT-DNA were monitored by microcalorimetry, showing they were all endothermic reactions with reaction within 27–42 min; interaction enthalpies (ΔH) of [Cu2L2(NO3)2] and HL were 30.3 and 4.31 kJ mol−1. Binding studies with BSA were evaluated by fluorescence spectroscopy and the same relative interactions were found comparing with the above CT-DNA experiments.

Three new acyl hydrazone compounds C12H12N4O3 (I), C12H14N4O4 (II) and C16H16N4O3 (III) are synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The crystal structural analyses show that the three compounds crystallize in the monoclinic crystal lattice. Their thermal decomposition processes under nitrogen and air are studied by TG-DTG, the sequence of the thermostability for three compounds at each condition is the same: III > I > II. The interaction modes of the three compounds with CT-DNA are investigated by UV–Vis absorption, showing hyperchromic and hypochromic effects. The thermogenic curves of the three compounds reacting with CT-DNA are measured by microcalorimetry, indicating that they are all endothermic reaction and the reaction times are within 10–30 min.

The use of the Schiff-base ligand N,N′-bis(3-methoxysalicylidene)ethylene-1,2-diamine (H2L) and fumarate (fum) enables the construction of the hexanuclear luminescent Zn–Ln complexes [Zn4Ln2L4(fum)2] (NO3)2·3CH3OH (Ln = Nd 1; Yb 2; Er 3; Gd 4). The complexes have been characterized by elemental analysis, FT-IR spectra and ESI mass spectrometer. The single crystal X-ray crystallographic study has been carried out on 1. Luminescent properties of these complexes including UV–Vis absorption spectra, excitation, visible and NIR region emission spectra, and NIR emission lifetime have been determined. The intrinsic near-infrared luminescent quantum yield of 1 and 2 are estimated to be 0.63% and 0.84% calculated from the observed lifetime and the natural lifetime of the lanthanide ions, respectively. Systematic analysis suggests that enhancement of near infrared emission could be observed upon construction of the stable polynuclear structures.

With a novel asymmetric Schiff-base zinc complex ZnL(H 2 L = N-(3-methoxysalicylidene)-N’-(5-(4-cyanophenyl)-3-methoxysalicylidene)phenylene-1, 2-diamine), obtained from phenylene-1, 2-diamine, 3-methoxysalicylaldehyde, and 5-(4-cyanophenyl)-3-methoxysalicylaldehyde, as the precursor, a series of heterobinuclear Zn-Ln complexes [ZnLnL(NO 3 ) 3 (CH 3 CN)] (Ln = La, 1; Ln = Nd, 2; Ln = Eu, 3; Ln = Gd, 4; Ln = Tb, 5; Ln = Er, 6; Ln = Yb, 7) were obtained by further reaction with Ln(NO3)3 · 6H2O. Photophysical studies of these complexes show that the strong and characteristic NIR luminescence with emissive lifetimes in the microsecond range has been sensitized from the excited state of the asymmetric Schiff-base ligand due to effective intramolecular energy transfer.

Cu(C10H11O2N2)2 (1) and [Zn(C10H12O2N2)2(H2O)2](NO3)2 (2) were synthesized and characterized by elemental analysis, FT-IR spectra, UV-Vis absorption spectroscopy, and X-ray single-crystal diffraction. Both complexes show distorted octahedral geometry. In 1, Cu(II) is coordinated by four oxygen atoms from four ligands and two nitrogen atoms from two ligands. In 2, Zn(II) is coordinated by two oxygen atoms and two nitrogen atoms from two ligands, and two water molecules. The crystal structures suggest that original ligand o-carboxybenzaldehyde salicyloylhydrazone (C15H12O4N2) changed into acetone salicyloylhydrazone (C10H12O2N2). The TG-DTG curves of these complexes indicate two different decomposition processes. 1 and 2 display catalytic activities to decomposition of hydrogen peroxide. Interaction between the complexes and DNA studied by UV-Vis titration shows the insert interaction.

With a novel asymmetric Schiff-base zinc complex ZnL (H2 L = N-(3-methoxysalicylidene)-N'-(5-bromo-3-methoxysalicylidene)phenylene-1,2-diamine), obtained from phenylene-1,2-diamine, 3-methoxysalicylaldehyde and 5-bromo-3-methoxysalicylaldehyde, as the precursor, a series of heterobinuclear Zn-Ln complexes [ZnLnL(NO3 )3 (CH3 CN)] (Ln = La, 1; Ln = Nd, 2; Ln = Eu, 3; Ln = Gd, 4; Ln = Tb, 5; Ln = Er, 6; Ln = Yb, 7) were synthesized by the further reaction with Ln(NO3 )3 ·6H2 O, and characterized by Fourier transform-infrared, fast atom bombardment mass spectroscopy and elemental analysis. Photophysical studies of these complexes show that the strong and characteristic near-infrared luminescence of Nd(3+) , Yb(3+) and Er(3+) with emissive lifetimes in the microsecond range has been sensitized from the excited state of the asymmetric Schiff-base ligand due to effective intramolecular energy transfer; the other complexes do not show characteristic emission due to the energy gap between the chromophore and lanthanide ions.

article With ZnL 1 or ZnL 2 from the simple Salen-type Schiff-base ligand H2L 1 (H2L 1 N,N'-bis(3-methoxysalicylidene)