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We report a novel resin-protected calcination process for preparing hollow TiO2 nanoshells with controllable crystallinity and phase. This method involves coating a template core with TiO2 and then a protection layer through sol–gel processes and then crystallization of the TiO2 shell by calcination. Through a systematic study on the crystallization behaviour of the TiO2 hollow shells with variation in core template and outer protection layer, we find that the grain growth and phase transformation of TiO2 is determined by several parameters such as the protection material, core composition, and calcination conditions. In particular, the use of a crosslinked polymer as the protection layer for calcination, enables the production of TiO2 shells with high crystallinity and controllable anatase–rutile mixed phases, which show significantly enhanced photocatalytic activity compared to those produced by SiO2-protected calcination. The photocatalytic activity could be further improved by improving the water dispersity of TiO2 shells through base treatment. With the ease of achieving photocatalytic activity comparable to commercial Degussa-P25 TiO2, it is expected that the TiO2 shells with controllable crystallinity and phase could be further engineered by incorporating more active components for producing highly active composite photocatalysts.

A novel coumarin-based fluorescent probe L ((4E)-4((7-hydroxy-4-methy1-2-oxo-2H-chromen-8-yl) methyleneamino)-1,2-dihyydro-2,3-dimethy1-1-phenylpyrazol-5-one) has been developed as a simple and efficient chemosensor which exhibits a significant fluorescence reduction in the presence of metal cations. This sensor exhibits high selectivity and sensitivity toward Cu2+ over other common cations. The mechanism for detecting copper was evaluated by time-dependent density functional theory (TO-OFT) calculations and the coordination mode was also confirmed by density functional theory (DFT) calculations. Furthermore, results of cell imaging in this study indicate that this new probe may be useful for detection and monitoring of Cu2+ in biological applications. (C) 2014 Elsevier By. All rights reserved.

In bone tissue engineering, it is imperative to design multifunctional biomaterials that can induce and assemble bonelike apatite that is close to natural bone. In this study, graphene oxide (GO) was functionalized by carrageenan. The resulting GO-carrageenan (GO-Car) composite was further used as a substrate for biomimetic and cell-mediated mineralization of hydroxyapatite (HA). It was confirmed that carrageenan on the GO surface facilitated the nucleation of HA. The observation of the effect of the GO-Car on the adhesion, morphology, and proliferation of MC3T3-E1 cells was investigated. In vitro studies clearly show the effectiveness of GO-Car in promoting HA mineralization and cell differentiation. The results of this study suggested that the GO-Car hybrid will be a promising material for bone regeneration and implantation.

We have successfully fabricated and tested the electrochemical performance of supercapacitor electrodes consisting of Ni(OH)2 nanosheets coated on NiCo2O4 nanosheets grown on carbon fiber paper (CFP) current collectors. When the NiCo2O4 nanosheets are replaced by Co3O4 nanosheets, however, the energy and power density as well as the rate capability of the electrodes are significantly reduced, most likely due to the lower conductivity of Co3O4 than that of NiCo2O4. The 3D hybrid composite Ni(OH)2/NiCo2O4/CFP electrodes demonstrate a high areal capacitance of 5.2 F/cm(2) at a cycling current density of 2 mA/cm(2), with a capacitance retention of 79% as the cycling current density was increased from 2 to 50 mA/cm(2). The remarkable performance of these hybrid composite electrodes implies that supercapacitors based on them have potential for many practical applications.

In this work, we have successfully provided a new fluorescent probe based on coumarin and quinoline (CQ) for detecting copper ion. This system utilizes such a chemical process, which responses instantaneously at room temperature with linear proportionality to the amount of copper ion. The receptor can be applied to monitoring of Cu

A rhodamine-based probe bearing an N,N-dimethylaniline unit was developed as a fluorescent chemodosimeter for Ce 4+ in aqueous media. Importantly, the sensor can selectively respond to Ce 4+ over other commonly coexistent metal ions (such as La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Er 3+ , Tb 3+ , Ho 3+ , Tm 3+ , Yb 3+ , Lu 3+ , Y 3+ ) in aqueous media with a rapid response time. The system, which utilizes an irreversible Ce 4+ -promoted oxidation reaction, responds instantaneously at room temperature with linear proportionality to the amount of Ce 4+ .

Two new water-soluble solid complexes [PrL (NO3)2(CH3OH)] (NO3), [NdL(NO3)2(CH3OH)](NO3)(L = 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperaziny)-7-oxo-7H-pyrido [1,2,3-de]-1,4-benzoxazine-6-carbaldehyde benzoyl hydrazone) have been synthesized by the reaction of Ln(III) nitrate with an ofloxacin derivative. The crystal structures of [PrL(NO3)2(CH3OH)](NO3) and [NdL(NO3)2(CH3OH)](NO3) were determined by single-crystal X-ray diffraction. The interactions of the ligand and Ln(III) complexes with calf thymus DNA (CT DNA) have been investigated by UV–Vis (UV–Vis) spectra, ethidium bromide (EB) displacement experiments, circular dichroism (CD) spectra, cyclic voltammetry (CV) and viscosity measurements. Experimental results indicated that Ln(III) complexes and ligand could bind to CT DNA via the intercalation mode and that the binding affinities of Ln(III) complexes are higher than that of free ligand. In addition, Ln(III) complexes could cleave pBR322 DNA in the presence and the absence of reductant. The free ligand did not show any DNA-cleaving abilities. Furthermore, the antioxidant activity of the ligand and Ln(III) complexes was determined by superoxide and hydroxyl radical scavenging methods in vitro, which indicate that the Ln(III) complexes exhibit more effective antioxidant activity than the ligand alone.

A novel selective fluorescent chemosensor based on an 8-hydroxyquinoline-appended fluorescein derivative (L1) was synthesized and characterized. Once combined with Cu(2+), it displayed high specificity for sulfide anion. Among the various anions, only sulfide anion induced the revival of fluoresecence of L1, which was quenched by Cu(2+), resulting in "off-on"-type sensing of sulfide anion. What's more, the sensor was retrievable to indicate sulfide anions with Cu(2+), and S(2-), in turn, increased. With the addition of Cu(2+), compound L1 could give rise to a visible pink-to-yellow color change and green fluorescence quenching. The resulting yellow solution could change to pink and regenerate to green fluorescence immediately upon the addition of sulfide anion; however, no changes were observed in the presence of other anions, including CN(-), P(2)O(7)(4-), and other forms of sulfate, making compound L1 an extremely selective and efficient sulfide chemosensor. The signal transduction occurs via reversible formation-separation of complex L1Cu and CuS. What's more, the biological imaging study has demonstrated that the chemosensor can detect sulfur anions in biological systems at a relatively low concentration.

In this study, we present the synthesis of reduced graphene oxide/hydroxyapatite (RGO/HA) hybrid materials by an environmental-friendly route. Graphene oxide (GO) was first simultaneously reduced and surface functionalized by one-step oxidative polymerization of dopamine (PDA). The bioinspired surface was further used for biomimetic mineralization of hydroxyapatite. When incubated in a simulated body fluid (SBF), the PDA layer enabled efficient interaction between the RGO surface and the mineral ions to improve the bioactivity, promoted the formation of the HA nanoparticles. A detailed structural and morphological characterization of the mineralized composite was performed. The HA-based hybrid materials exhibited no cytotoxic effect on L929 fibroblast cells, showing potential capacity of being a scaffold material for bone tissue regeneration and implantation. This facile strategy also can be a useful platform for other RGO-based nanocomposites.

A superparamagnetic graphene oxide–Fe3O4 hybrid composite (GO–Fe3O4) was prepared via a simple and effective chemical method. Amino-functionalized Fe3O4 (NH2-Fe3O4) particles are firmly deposited on the graphene oxide sheets. The graphene oxide sheets could prevent NH2-Fe3O4 particles from agglomeration and enable a good dispersion of these oxide particles. The as-prepared GO–Fe3O4 hybrid composite had a much higher thermal stability than graphene oxide. The amount of NH2-Fe3O4 loaded on GO was estimated to be 23.6 wt% by atomic absorption spectrometry. The specific saturation magnetization (Ms) of the GO–Fe3O4 hybrid composite is 15 emu g−1. The magnetic GO–Fe3O4 composite has been employed as adsorbent for the magnetic separation of dye contaminants from water. The adsorption test of dyes (Methylene Blue (MB) and Neutral Red (NR)) demonstrates that it only takes 30 min for MB and 90 min for NR to attain equilibrium. The adsorption capacities for MB and NR in the concentration range studied are 167.2 and 171.3 mg g−1, respectively. The GO–Fe3O4 hybrid composite can be easily manipulated in magnetic field for desired separation, leading to the removal of dyes from polluted water. These GO–Fe3O4 hybrid composites have great potential applications in removing organic dyes from polluted water.

A fluorescent, colorimetric chemosensor, L1, based on 8-aminoquinoline, has been developed as a sensor for Zn2+. L1 exhibited high selectivity and sensitivity towards Zn2+ over other common metal ions in a physiological pH window with a 1:1 binding mode. The ability of L1 to monitor intracellular Zn2+ in living cells has been examined by fluorescence microscopy and indicated that L1 is cell-permeable and biocompatible. We hope that such Zn2+-selective sensors will find application in biomedical and environmental detection.

Salicylaldehyde 2-phenylquinoline-4-carboylhydrazone (H 2 L), and its novel tetranuclear cobalt(II), nickel(II) complexes have been synthesized and characterized. The crystal structure of (NiL) 2 ·[NiL(H 2 O)(DMF)] 2 ·H 2 O·DMF obtained from DMF solutions of compound 2 was determined by X-ray diffraction analysis. The DNA-binding investigation suggests that the two complexes bind to DNA via groove binding mode. The in vitro antibacterial activity of complexes against Escherichia coli , Staphylococcus aureus , Bacillus subtilis was screened and compared to the activity of the free ligand, the antibacterial activity of complex 1 is active than complex 2 which is in consistent with their DNA-binding behaviors.

Two novel copper(II) thiocyanate complexes with 4-( N , N -dimethylamino) pyridine and N , N -dimethylformamide( 1 ) and with4-( N , N -dimethylamino) pyridine ( 2 ) have been synthesized and characterized. The crystal and molecular structures of complexes 1 and 2 were determined by single-crystal X-ray diffraction. Antioxidative activity tests in vitro showed that complex 1 has significant antioxidative activity against hydroxyl free radicals from the Fenton reaction and also oxygen free radicals, which is better than standard antioxidants like vitamin C and mannitol. The interaction of complex 1 with calf thymus DNA was investigated by spectroscopic, cyclic voltammetry, and viscosity measurements. Results suggest that complex 1 can bind to DNA via partial intercalation mode. Moreover, complex 1 has been found to cleavage of plasmid DNA pBR322.

Various fluorescent nanoparticles have been applied in imaging of tissues or intracellular structures. Searching for biocompatible nanoparticles that can be observed under visible light is of fundamental importance for the applications in living cells. In this study, a simple, template-based route for the synthesis of fluorescent hydroxyapatite (HA) nanoparticles has been developed. Well-dispersed HA nanoparticles prepared by using SiO2 as templates (THA) were surface-functionalized with fluorescein isothiocyanate (FITC), resulting in bright and stable fluorescent particles (THA-FITC). These fluorescent nanoparticles were demonstrated to be internalized into Hela cells and have no apparent cytotoxic effects on fibroblast cells, which confirmed the biocompatibility and cell labeling capability of the nanoparticles. Due to the large surface areas, porous nature, and visible light excited luminescence characters, THA-FITC nanoparticles will have applications in fields such as cell labeling, whole animal imag...

A rhodamine-based fluorogenic probe bearing the quinaldine unit (L1) was developed as a turn-on fluorescent chemosensor for Cu2+. Upon binding with Cu2+, comparable amplifications of absorption and fluorescence signals were observed, which suggest that chemosener L1 effectively avoided the fluorescence quenching caused by the paramagnetic nature of Cu2+. Importantly, Li can selectively respond to Cu2+ over other commonly coexistent metal ions (such as K, Ca2+, Mg2+, Ni2+, Co2+, Fe2+, Fe3+, Hg2+, Zn2+, Cr3+) in aqueous media with a rapid response time (

The water-soluble Pr (III) and Nd (III) complexes with an ofloxacin derivative have been prepared and characterized. The single-crystal X-ray diffraction showed that the Pr (III) and Nd (III) complexes have the similar molecular structure. Under physiological pH condition, the effects of [PrL(NO3)(2) (CH3OH)](NO3) and [NdL(NO3)(2)(CH3OH)](NO3) on bovine serum albumin (BSA) were examined using fluorescence spectroscopy in combination with UV-vis absorbance and circular dichroism (CD) spectra. The result reveals that the quenching mechanism of fluorescence of BSA by two complexes is a static quenching process and the number of binding sites is about 1 for both. The thermodynamic parameters (Delta H= -14.52 kJ mol(-1), Delta S=56.54 J mol(-1) K-1 for [PrL(NO3)(2)(CH3OH)](NO3) and Delta H= -24.63 kJ mol(-1), Delta S=22.07 J mol(-1) K-1 for [NdL(NO3)(2)(CH3OH)](NO3)) indicate that hydrophobic and electrostatic interactions are the main binding force in the complexes-BSA system. The binding average distance between complexes and BSA was obtained on the basis of Forster's theory. In addition, it was proved by the CD spectra that the BSA secondary structure was changed in the presence of complexes in an aqueous solution. (C) 2011 Elsevier B.V. All rights reserved.

Tris[2-(8-chinolinyloxy)ethyl]amine (L) has been developed as a highly selective fluorescent chemosensor for Cd2+ based on the chelation-enhanced fluorescence (CHEF) mechanism. Its sensing behavior toward metal ions was investigated by absorption and fluorescence spectroscopy. In buffer solution (10 mM Tris–HCl, pH = 7.4) of L, the presence of Cd2+ induces the formation of a metal–ligand (Cd2+–L) complex, which exhibits a strong, increasing fluorescent emission centered at 417 nm. The binding mode of the Cd2+–L complex has been found to be 1:1 based on the fluorescence/absorption titration and further confirmed by X-ray crystallography.

A fluorescent probe based on 8-aminoquinoline bearing an aminophenol unit (L1) was developed as a chemosensor for Zn(2+). Sensor L1 exhibits a high selectivity and sensitivity towards Zn(2+) over other common metal ions in the physiological pH window and binds to Zn(2+) through 1:1 binding mode. Fluorescent imaging of Zn(2+) in living cells is also successfully demonstrated.

The reaction of Co(NO3)2 · 6H2O with a tripodal ligand leads to a new complex {[Co(L)] · 2NO3 · 8H2O} (1) confirmed by single-crystal X-ray diffraction, infrared spectroscopy, and elemental analysis. The particular interest of 1 is in the formation of a 1-D water tape consisting of (H2O)16 cluster units, the neighboring water tapes are connected by free nitrate anions via hydrogen bonds into a 2-D guest layer. These guest layers are alternately packed face-to-face with the 2-D host layers along the a-axis to form a 3-D supramolecular architecture. There exist C–H ··· N and C–H ··· O weak hydrogen bonds between the guest layer and host layer. These weak hydrogen bonds and water–nitrate, water–water hydrogen bonds are important for the stability of the overall structure.

A symmetric ligand 2, 6-di ((phenazonyl-4-imino)methyl)-4-methylphenol (Dpmp) and its cobalt dinuclear complex (Co2(Dpmp)2(NO3)2(H2O)2·NO3·EtOH, (1) and zinc mononuclear complex Zn(Dpmp)(NO3)2, (2) have been prepared. The crystal structures were determined by single-crystal X-ray diffraction. The biological activity has been evaluated by examining their anti-oxidative activity and ability to bind to bovine serum albumin (BSA) and calf-thymus DNA (CT DNA) with UV–vis absorption, fluorescence, viscosity measurements and circular dichroism (CD) spectroscopies. The complexes exhibit good binding propensity to BSA and CT DNA. Both 1 and 2 have been found to promote cleavage of pUC19 DNA in the absence of any reducing agent. Antioxidant tests in vitro show the compounds possess significant antioxidant activity against superoxide and hydroxyl radicals.

A fluorescent ruthenium (Ru) complex is coupled to magnetic Fe3O4 nanoparticles (NPs) via3-(3,4-dihydroxyphenyl) propanoic acid (DHPPA) and O,O′-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol (PPG-PEG-PPG-diamine). The resultant Ru–Fe3O4 NP conjugate shows excellent colloidal, photochemical and magnetic stability, and is promising as a dual functional probe for biological imaging applications.

The binding properties on [PrL2(NO3)](NO3)2 (L = 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperaziny)-7-oxo-7Hpyrido[1,2,3-de]-1,4-benzoxazine-6-carbaldehyde benzoyl hydrazone) to bovine serum albumin (BSA) have been studied for the first time using fluorescence spectroscopy in combination with UV–Vis absorbance spectroscopy. The results showed that [PrL2(NO3)](NO3)2 strongly quenched the intrinsic fluorescence of BSA through a static quenching procedure, and non-radiation energy transfer happened within molecules. The number of binding site was about 1, and the efficiency of Forster energy transfer provided a distance of 4.26 nm between tryptophan and [PrL2(NO3)](NO3)2 binding site. At 288, 298, 310 K, the quenching constants of BSA–[PrL2(NO3)](NO3)2 system were 5.11 × 104, 4.33 × 104 and 3.71 × 104 l M−1. ΔH, ΔS and ΔG were obtained based on the quenching constants and thermodynamic theory (ΔH 0 and ΔG < 0). These results indicated that hydrophobic and electrostatic interactions are the mainly binding forces in the [PrL2(NO3)](NO3)2–BSA system. In addition, the CD spectra have proved that BSA secondary structure changed in the presence of [PrL2(NO3)](NO3)2 in aqueous solution. Moreover, the interaction between [PrL2(NO3)](NO3)2 and calf thymus DNA (CT DNA) was studied by spectroscopy and viscosity measurements, which showed that the binding mode of the [PrL2(NO3)](NO3)2 with DNA is intercalation. The DNA cleavage results show that in the absence of any reducing agent, the [PrL2(NO3)](NO3)2 can cleave plasmid pBR322 DNA and its hydrolytic mechanism was demonstrated with hydroxyl radical scavengers and singlet oxygen quenchers.

A novel fluorescent sensor 4((E)-(N-(rhodamine-6G)lactam-ethylenediamineimino)methyl)benzene-1,3-diol (1), which has a unique spirolactam ring formation, show a reversible, selective, and sensitive fluorescence enhancement response to Cu(II) at biological pH value for practical use. Also, the selectivity of this system for Cu(II) over other metal ions is remarkably high, and its sensitivity is below 2 ppb in methanol solutions. Furthermore, its high cell permeability grants the access to employ 1 as Cu(II) detector in living cells. (C) 2010 Elsevier B.V. All rights reserved.

2-((4-Methoxyphenoxy) carbonyl) benzoic acid, 2-(1-methoxyvinyl) benzoic acid and their rare earth complexes LnL(2)(OH).3H(2)O (Ln=La, Eu, Tb) were synthesized and characterized by means of elemental analysis, FTIR, (1)H NMR, UV and luminescence spectroscopy. The FTIR and (1)H NMR results show that the carboxylic groups in the complexes coordinated to the rare earth ions in the form of one dentate, and the ester carboxylic groups have taken part in the coordination. Among these complexes, Eu(III) complexes and Tb(III) complexes exhibit characteristic fluorescence with comparatively high brightness and good monochromaticity, which indicated that the ligands of HL(I) and HL(II) are good organic chromophore to absorb and transfer energy to metal ions.

A series of new complexes of poly(styrene-co-methacrylic acid) with Ln(III) (Ln = La, Eu, Tb) were synthesized and well characterized by means of elemental analysis, FTIR, differential scanning calorimetric (DSC) analysis, TG-DTA analysis, X-ray diffraction (XRD), and fluorescence determination. The elemental analysis and FTIR studies showed that a large part of carboxylic groups on the side chain of the copolymer are coordinated with Ln(III) ions. The TG-DTA and DSC analysis results indicated that the complexes have good thermal stability. XRD experiments showed that copolymers and the complexes are amorphous. Among these complexes, Eu(III) complexes and Tb(III) complexes exhibit characteristic fluorescence with comparatively high brightness and good monochromaticity. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 3388-3394, 2009

(E)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its Ce(IV), Th(IV), and UO2(II) complexes were synthesized and characterized by MS, elemental analysis, IR, UV, TG-DTA, and NMR. The complexes have composition [CeL2(OH)2 · 2H2O] · H2O, [ThL2(OH)2 · 2H2O] · H2O, and [UO2L2 · 2H2O] · H2O. Molar conductance data confirm that the three complexes are nonelectrolytes. The IR and NMR results show that the carboxylates coordinate to the metal ions bidentate, and the ester carboxylic groups do not take part in coordination. Luminescence spectra of the ligand and complexes in DMSO at room temperature were also studied showing strong luminescence of the metal ions.

The synthesis and spectral properties of a chemidosimeter 1,4-di[2-(6-ethylamino-3-ethylimino-2,7-dimethyl-3H-xanthen-9-yl) benzoic acid (aminomethyl)-3-phenylthiourea] benzene (1) for Hg(II) ions are reported, and it has been demonstrated that 1 can be used as a fluorescent probe for monitoring Hg(II) ions in living cells. A highly sensitive fluorescent probe (1) was developed as a fluorescent and colorimetric chemodosimeter in dimethyl sulfoxide/methanol solution with a broad pH range (pH 5–10) and high selectivity toward Hg2+ ions but no significant response toward other competitive cations. Furthermore, by means of confocal laser scanning microscopy experiments, it is demonstrated that 1 can be used as a fluorescent probe for monitoring Hg2+ in living cells.

2-Phenylquinoline-4-carboylhydrazide (HL), and its novel nickel(II), zinc(II) complexes [M(HL)(2)(L)].2H(2)O.NO(3) (M=Ni (1), M=Zn (2)), have been synthesized and characterized by elemental analysis, molar conductivity, and IR spectra. The crystal structure of [Ni(HL)(2)(L)].2H(2)O.NO(3) obtained from ethanol solution was determined by X-ray diffraction analysis, crystallized in the rhombohedral system, space group R3 , Z=18, a=31.913(3)A, b=31.913(3)A, c=27.709(2)A, alpha=90 degrees , beta=90 degrees , gamma=120 degrees , R(1)=0.0647. The interactions of the complexes and the ligand with calf thymus DNA had been investigated using UV-Vis spectra, fluorescent spectra, CD (circular dichroism) spectra, CV (cyclic voltammetry) and viscosity measurements. These compounds were tested against MFC (mouse forestomach carcinoma) cell lines. The complex 1 showed significant cytotoxic activity against MFC cell lines. The cleavage reaction on plasmid DNA has been monitored by agarose gel electrophoresis. Results suggest that the two complexes bound to DNA via a groove binding mode and the complexes can cleave pBR322 DNA.

The interaction between bovine serum albumin (BSA) and the cobalt(II) complex with salicylaldehyde-2-phenylquinoline-4-carboylhydrazone (Co-SPC) was investigated using fluorescence spectroscopy, UV absorption, and circular dichroism (CD) under simulated physiologic conditions for the first time. Fluorescence data and UV absorption spectra revealed that the intrinsic fluorescence of BSA was strongly quenched by Co-SPC in terms of a static quenching process at a lower concentration of the complex and a combined quenching process at a higher concentration of the complex. Binding constants and binding sites were evaluated. The average binding distance between Co-SPC and BSA was obtained (2.28 nm) on the basis of Förster's theory. The thermodynamic parameters indicated that hydrophobic force played a major role in the binding. The binding of Co-SPC to BSA leads to changes in the conformation of BSA according to synchronous fluorescence spectra and CD data.

A series of complexes of poly(N,N-diethylacrylamide-co-methacrylic acid) (PDEA-co-MAA) with Ln(III) (Ln = La, Eu, Tb) were synthesized and characterized by X-ray diffraction, elemental analysis, FT-IR and TG-DTA. The luminescence spectra of Eu(III) and Tb(III) complexes in solid state were also studied. The complexes exhibit strong characteristic luminescence of Eu(III) and Tb(III) ions, while the luminescence intensity depend on the content of DEA and Ln(III) ions.

1-Cyclohexyl-3-tosylurea (HL) and its two complexes, ML 2 ·2H 2 O [M Ni( 1 ), and Cd( 2 )], have been synthesized and characterized on the basis of elemental analyses, molar conductivities, IR spectra and thermal analyses. In addition, the DNA-binding properties of the ligand and the two complexes have been investigated by electronic absorption, fluorescence, CD spectroscopy and viscosity measurements. The experiment results suggest that the ligand and its two complexes bind to DNA via a groove binding mode, and the binding affinity of the complex 2 is higher than that of the complex 1 and the ligand.

The interaction of 1-phenyl-3-(coumarin-6-yl)sulfonylurea (SU22) with bovine serum albumin (BSA) has been investigated by fluorescence quenching spectroscopy combined with UV-absorption, circular dichroism (CD), Fourier transform infrared (FT-IR) spectroscopy techniques under simulative physiological conditions for the first time. Fluorescence data and UV-absorption spectra revealed that the quenching mechanism of fluorescence of BSA by SU22 was a static quenching process and the number of binding sites was about 0.8858; the thermodynamic parameters (Δ G = −29.23 kJ mol −1 , Δ H = −47.48 kJ mol −1 , and Δ S = −61.24 J mol −1 K −1 ) explained that hydrogen bond and Van der Waals interaction were the main binding force stabilizing the complex. The binding average distance between SU22 and BSA was obtained (3.20 nm) on the basis of the Forster’s theory. In addition, The CD spectra and FT-IR spectra have proved that BSA secondary structure changed in the presence of SU22 in aqueous solution.

1-(4-Aminoantipyrine)-3-tosylurea (H2L) and its three lanthanide (III) complexes, M(H2L)3 3NO3 [where M = Nd(III), Sm(III) and Eu(III)], have been synthesized and characterized. In addition, the DNA-binding properties of the three complexes have been investigated by UV–vis (ultraviolet and visible) absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, cyclic voltammetry, and viscosity measurements. Results suggest that the three complexes bind to DNA via a groove binding mode. Furthermore, the antioxidant activity (superoxide and hydroxyl radical) of the metal complexes was determined by using spectrophotometer methods in vitro. These complexes were found to possess potent antioxidant activity and be better than standard antioxidants like vitamin C and mannitol.

Amorphous phosphor 1.4Y 2 O 3 .2.5Al 2 O 3 .0.1Tb 2 O 3 (the same composition as Y 2.8 Tb 0.2 Al 5 O 12 ) was prepared via a sol-gel method at relatively low temperature (i.e., below 650 °C), which is much lower than that for the preparation of polycrystalline Y 3 Al 5 O 12 :Tb 3+ (above 1400 °C). The amorphous phosphor prepared in the optimized conditions showed a bright green-yellowish luminescence, the intensity of which was comparable with that of polycrystalline sample and the emissions of which were assigned to 5 D 4 → 7 F j transitions of Tb 3+ . Besides the emissions of Tb 3+ , the amorphous samples prepared at temperatures below 500 °C presented a weak blue emission band around 420 nm.

Salicylaldehyde 2-phenylquinoline-4-carboylhydrazone (H2L), and its novel copper(II), cobalt(II), and nickel(II) complexes MHL · Cl · nH2O [M=Cu n = 3 (1), M=Co n = 2 (2), M=Ni n = 3.5 (3)] have been synthesized and characterized by elemental analysis, molar conductivity, spectroscopic, and thermal analysis. The interaction of these complexes with calf thymus DNA was investigated by UV absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and viscosity measurements. The results suggest that these complexes bind to DNA via an intercalation binding mode and their affinity to DNA follows the order of 3 > 1> 2.

A novel organic–inorganic hybrid tungstotellurate [Na(H2O)3]2[{Cu(2,2′-bipy)2}2(TeW6O24)] · 4H2O, has been synthesized and characterized by elemental analyses, IR spectra, TG analyses, and single-crystal X-ray diffraction. The saturated Anderson-type polyoxoanions are covalently bonded with two [Cu(2,2′-bipy)2]2+, and linked by Na+ into an infinite one-dimensional chain. Furthermore, the three-dimensional supramolecular architectures are formed by π–π stacking interactions of the 2,2′-bipyridine groups between adjacent layers and the hydrogen-bonding interactions respectively.

1-(Pyridin-2-yl)-3-tosylurea(HL) and its two lanthanide complexes, LnL3 · H2O [Ln = Nd(1), Eu(2)], have been synthesized and characterized on the base of elemental analyses, molar conductivities, IR spectra and thermal analyses. In addition, the DNA-binding properties of the two complexes have been investigated by absorption, fluorescence and viscosity measurements. The experimental results indicated that the complex (1) and (2) can bind to DNA; the binding affinity of the complex (1) is higher than that of complex (2) and the intrinsic binding constants of complex (1) and complex (2) with DNA were 1.24 × 104 m −1 and 8.7 × 103 m −1, respectively. In addition, some factors that influence the fluorescent intensity were also discussed.

Three new Schiff base ligands N-(3-formyl-5-methylsalicylidene)-2-aminoethanol (H2L1), N-(3-hydroxylmethyl-5-methylsalicylidene)-2-aminoethanol (H3L2), 2,6-bis(o-carboxyphenyliminomethene)-4-methylphenol (H3L3) and their binuclear ZnII complexes [Zn2(HL1)2]Cl2 · 2H2O (ZnHL1), [Zn2(H2L2)2]Cl2 · H2O (ZnH2L2) and [Zn2(HL3)Cl2] · H2O (ZnHL3) were synthesized and characterized by 1H-NMR, elemental analysis, IR and molar conductivity. The results suggest, in every case, two Zn2+ ions were bridged by phenolic OH group oxygen, forming a binuclear complex. The binding properties of these complexes to calf thymus DNA (ct-DNA) were investigated. Absorption and fluorescence spectra are together suggestive that both ZnHL1 and ZnHL3 interact with ct-DNA through intercalative mode, while ZnH2L2 interact with ct-DNA by non-intercalative interaction. Moreover, ZnHL3 can bind to ct-DNA more strongly than ZnHL1. These complexes also exhibited good scavenging activity on the hydroxyl radical (•OH), which are better than those of their corresponding ligands.

We report a facile modification of graphene oxide (GO) by gelatin to mimic charged proteins present in the extracellular matrix during bone formation. The bioinspired surface of GO–gelatin (GO–Gel) composite was used for biomimetic mineralization of hydroxyapatite (HA). A detailed structural and morphological characterization of the mineralized composite was performed. Additionally, MC3T3-E1 cells were cultured on the GO–Gel surfaces to observe various cellular activities and HA mineralization. Higher cellular activities such as cell adhesion, cell proliferation, and alkaline phosphatase activity (ALP) were observed on the GO–Gel surface compared with the GO or glass surface. The increase of ALP confirms that the proposed GO–Gel promotes the osteogenic differentiation of MC3T3-E1 cells. Moreover, the evidence of mineralization evaluated by scanning electron microscopy (SEM) and alizarin red staining (ARS) corroborate the idea that a native osteoid matrix is ultimately deposited. All these data suggest that the GO–Gel hybrids will have great potential as osteogenesis promoting scaffolds for successful application in bone surgery.

In this paper two metalorganic complexes of dicyclopentadienyltitanium(IV) with aspirin and dicyclopentadienyltitanium(IV) with salicylic acid have been synthesized. Their chemical compositions and structures have been studied by elemental analyses, XPS, IR, 1H NMR. The formulas of the complexes were confirmed as (Cp)2Ti(Asp)2 and (Cp)2Ti(Sal)2 [Cp = cyclopentadienyl ion (η5-C5H5), Asp = anion of aspirin (acetylsalicylate ion, CH3CO2C6H4COO−), Sal = salicylate anion, C6H4(OH)COO−], in which the carboxyl oxygen atoms of Asp and Sal are coordinated to Ti(IV) in a monodentate manner. It was found that the complexes of Sal or Asp and cyclopentadienyl ion have a “synergistic action” on the elimination of superoxide radicals (O2 −•) and hydroxyl radicals (OH•). The possible mechanism of these reactions has been discussed.

A novel coumarin-based fluorescent probe L ((4E)-4-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl) methyleneamino)-1,2-dihyydro-2,3-dimethyl-1-phenylpyrazol-5-one) has been developed as a simple and efficient chemosensor which exhibits a significant fluorescence reduction in the presence of metal cations. This sensor exhibits high selectivity and sensitivity toward Cu(2+) over other common cations. The mechanism for detecting copper was evaluated by time-dependent density functional theory (TD-DFT) calculations and the coordination mode was also confirmed by density functional theory (DFT) calculations. Furthermore, results of cell imaging in this study indicate that this new probe may be useful for detection and monitoring of Cu(2+) in biological applications.

In this study, monodisperse palladium (Pd) nanoparticles on reduced graphene oxide (RGO) surfaces were successfully prepared by a "wet" and "clean" method in aqueous solution. Without any surface treatment, Pd nanoparticles are firmly attached to the RGO sheets. These RGO/Pd nanocomposites exhibited catalytic activity in hydrogen generation from the hydrolysis of ammonia borane (AB). Their hydrolysis completion time and activation energy were 12.5 min and 51 ± 1 kJ mol(-1), respectively, which were comparable to the best Pd-based catalyst reported. The TOF values (mol of H(2)× (mol of catalyst × min)(-1)) of RGO/Pd is 6.25, which appears to be one of the best catalysts reported so far. We also obtained a (11)B NMR spectrum to investigate the mechanism of this catalytic hydrolysis process. This simple and straightforward method is of significance for the facile preparation of metal nanocatalysts with high catalytic activity on proper supporting materials.

Magnetic 8 nm Fe(3)O(4) nanoparticles (NPs) were synthesized and modified with dopamine (DPA) and polyethylene glycol (PEG) diacid. The water soluble Fe(3)O(4)-DPA-PEG NPs were then conjugated with the fluorescent Eu(iii) complex of tris(dibenzoylmethane)-5-amino-1,10-phenanthroline (BMAP), giving an Fe(3)O(4)-DPA-PEG-BMAP-Eu NP conjugate. The conjugate was both colloidally and chemically stable in phosphate buffered solutions and could be used as a probe for magnetic resonance and fluorescent imaging.

The interaction between bovine serum albumin (BSA) and the anticancer drug molecule ampelopsin (AMP) was investigated using fluorescence spectroscopy, circular dichroism (CD) spectra, and time-resolved spectra under simulated physiological conditions. Fluorescence data showed that the intrinsic fluorescence of BSA was strongly quenched by AMP in terms of a dynamic quenching process. Binding constants and binding sites were calculated. The thermodynamic parameters indicated that the hydrogen bonding and weak van der Waals force played a major role in the interaction. The site marker competitive experiments suggested that the binding site of AMP and BSA was probably located on site III. Based on the Forster's theory, the average binding distance between AMP and BSA was obtained (r = 5.47 nm). The binding of AMP and BSA leaded to conformational changes of BSA according to synchronous fluorescence spectra, CD data and mean fluorescence lifetime values.

A new fluorescent sensor L1 based on coumarin was synthesized. It shows high sensitivity and selectivity toward Cu(2+) in aqueous solution. The complexation mode and corresponding quenching mechanism were elucidated by ESI-MS and DFT calculations. In addition, biological imaging studies have demonstrated that L1 can detect Cu(2+) in living cells.

A novel 4-(2,4-dihydroxybenzylideneamino)benzenesulfonic acid (HL), and its kalium(I), calcium(II) complexes [M(L)n]·2nH2O·Cln (M = K(1) n = 1, M = Ca(2) n = 2), have been prepared and characterized. The crystal and molecular structures of 1 and 2 were determined by single-crystal X-ray diffraction. The interaction of 1, 2 and ligand (L) with calf thymus DNA was investigated by UV–visible (UV–vis), fluorescence and viscosity measurements. Experimental results indicate that 1, 2 and L could bind to DNA via the intercalation mode, and the binding affinity of 1 is stronger than that of 2 and L. The intrinsic binding constants of 1, 2 and L were 5.60 × 105, 6.53 × 105 and 1.44 × 105 M−1, respectively. The cleavage reaction on plasmid DNA has been monitored by agarose gel electrophoresis. The results indicated that 1 and 2 could cleave pBR322 DNA.

A turn-on chemosensor L1, which exhibits high selectivity and sensitivity toward Hg(2+) over other common metal ions in aqueous media under a physiological pH window via a 1:1 binding mode, had been synthesized and characterized. L1 provides good fluorescent imaging of Hg(2+) in living cells. Particularly, we adopted the "micro computed tomography (MCT)" technology, successfully demonstrating the method of Hg(2+) sensing by L1 in cell lines, also the cell permeability of L1 and its imaging position in the cells.

A redox luminescence switch was prepared by doping hydroxyapatite nanoparticles with CePO4:Tb. The resulting multifunctional material exhibits good biocompatibility, biological affinity, and potential drug-carrying capability. The luminescent hydroxyapatite nanoparticles may find important applications in biomedical diagnostics, drug delivery, and biological sensors. This work demonstrated a biocompatible redox luminescence switch based on hydroxyapatite nanoparticles. The as-synthesized multifunctional nanoparticles have a large surface area and exhibit high biological affinity. This study will be quite relevant for developing a new system that may be applied in studying enzyme or protein activities based on fluorescent nanoparticles.

New complexes of hydrated lanthanide(III) nitrates with 2,6-bis(benzimidazol-2′-yl)pyridine (BBP) having the formulae [Ln(BBP) 2 (NO 3 ) 2 ]NO 3 · n H 2 O (where Ln = La-Nd, Sm-Tb, n = 1,2), [Ln(BBP)(BBPH)(NO 3 )(OH 2 )]NO 3 · n H 2 O (where Ln = Dy, Er, n = 3, 4) and [Ln(BBPH)(NO 3 ) 2 (OH 2 )] · 2H 2 O (where Ln = Lu) have been prepared and characterized by elemental analyses, IR and electronic spectra, molar conductance, thermal analyses and X-ray powder diffraction patterns. The emission spectra of all the complexes have also been examined. It has been found that all the complexes show the luminescence of the ligand. The Sm, Eu and Tb complexes also show the corresponding metal ion luminescence.