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A significant enhancement of the second harmonic generation (SHG) from second-order nonlinear optical (NLO) dyes in solution has been evidenced when these dyes were grafted onto the surface of spherical gold nanoparticles (AuNPs), as compared to their NLO response without AuNPs. The length, as well as the nature of the spacers between the gold particle and the chromophore, is shown to play an important role, a benzene linker being more favorable to AuNP-4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) interactions, as illustrated by a higher exaltation of the NLO response for DAST molecules linked to AuNP via a phenyl ring as compared to their equivalent with a CH2−CH2 link.

Hollow nanosphere H-Gd2O3:Eu3+ was fabricated by multi-step chemical incorporated with hole soft mold using glucose. The H-Gd2O3:Eu3+ monodisperse nanosphere was obtained after thermal treatment at 650 °C. The structural, morphological, and luminescence optical properties of fabricated transparent samples were determined by X-ray diffraction, transmission and field-emission scanning electron microscopies, UV–Visible spectroscopy, Fourier transform infrared spectroscopy, photoluminescence spectroscopy, and Brunauer–Emmett–Teller method. The hollow nanospheres with diameter in the range of 80-100 nm, and the thickness of the shell is about 19 nm tightly packed by nanoparticles. The material is strongly luminescent in the red region, peak emissions correspond to transition characteristics such as 580 (5Do – 7Fo), 592 (5Do – 7F1), 611 (5Do – 7F2), 650 (5Do – 7F3), and 692 nm (5Do – 7F4). The luminescence efficiency was calculated based on the Judd–Ofelt theory, the luminescence efficiency of hollow nanosphere H-Gd2O3:Eu3+ is higher 1.56 than times Gd2O3:Eu3+ 48.45% which leads for many transparent optical devices. [ABSTRACT FROM AUTHOR]

In this paper, the luminescent complex Eu(3-thenoyltrifluoroacetonate)3 was integrated with Fe3O4 and gold (Au) nanoparticles to form a multifunctional nanocomposite, Fe3O4/Au/Eu(TTA)3 (FOASET NC), for dual magnetic-photothermal therapy and biomedical imaging. Upon functionalization with amine-NH2, the FOASET NC exhibits a small size of 60–70 nm and strong, sharp emission at λmax = 614 nm, enhanced by surface plasmon resonance (SPR) of Au nanoparticles that provided an effective label for HT29 colorectal cancer cells by fluorescence microscopy imaging. In addition, a hyperthermia temperature (42–46 °C) was completely achieved by using these FOASET NCs in an aqueous solution with three heating modes for (i) Magnetic therapy (MT), (ii) Photothermal therapy (PT), and (iii) Dual magnetic-photothermal therapy (MPT). The heating efficiency was improved in the dual magnetic-photothermal heating mode. [ABSTRACT FROM AUTHOR]

We present a visual tool and facile method to detect MCF-7 breast cancer cells by using YVO4:Eu3+@silica-NH-GDA-IgG bio-nanocomplexes. To obtain these complexes, YVO4:Eu3+ nanoparticles with a uniform size of 10–25 nm have been prepared firstly by the hydrothermal process, followed by surface functionalization to be bio-compatible and conjugated with cancer cells. The YVO4:Eu3+@silica-NH-GDA-IgG nanoparticles exhibited an enhanced red emission at 618 nm under an excitation wavelength of 355 nm and were strongly coupled with MCF-7 breast cancer cells via biological conjugation. These bio-nanocomplexes showed a superior sensitiveness for MCF-7 cancer cell labelling with a detection percentage as high as 82%, while no HEK-293A healthy cells were probed under the same conditions of in vitro experiments. In addition, the detection percentage of MCF-7 breast cancer cells increased significantly via the functionalization and conjugation of YVO4:Eu3+ nanoparticles. The experimental results demonstrated that the YVO4:Eu3+@silica-NH-GDA-IgG bio-nanocomplexes can be used as a promising labelling agent for biomedical imaging and diagnostics. [ABSTRACT FROM AUTHOR]

The synthesis, spectroscopic and electrochemical data of donor-acceptor-donor tetrazines containing ferrocene moieties and phenyl unit as a [pi]-bridge are presented. The ultraviolet (UV)-vis spectroscopic and cyclic voltamperometric results have indicated sizable intramolecular charge transfer interactions in the ground state when the ferrocene is directly bound to the tetrazine and have shown reduction of the electron-donor strength of ferrocene moieties when there is a phenyl linkage.

We report on the synthesis and characterization of folic acid-conjugated silica-modified TbPO4·H2O nanorods for biomedical applications. The uniform shape TbPO4·H2O nanorods with a hexagonal phase were successfully synthesized by wet chemical methods. A novel TbPO4·H2O@silica-NH2 nanocomplex was then formed by functionalizing these nanorods with silica and conjugating with biological agents. The field emission scanning electron microscopy, energy-dispersive X-ray, and X-ray diffraction reveal the morphology and structure of the nanorods, with their controllable sizes (500-800 nm in length and 50-80 nm in diameter). The Fourier transform infrared spectroscopy was employed to identify chemical substances or functional groups of the TbPO4·H2O@silica-NH2 nanocomplex. The photoluminescence spectra show the four emission lines of TbPO4·H2O@silica-NH2 in folic acid at 488, 540, 585, and 621 nm under 355 nm laser excitation, which could be attributed to the 5D4-7 F j (J = 6 , 5 , 4 , 3) transitions of Tb3+. The TbPO4·H2O@silica-NH2 nanorods were conjugated with folic acid for the detection of MCF7 breast cancer cells. The obtained results show a promising possibility for the recognition of living cells that is of crucial importance in biolabeling. [ABSTRACT FROM AUTHOR]

The second-order nonlinear optical (NLO) properties of [Ln[(hfac).sub.3](diglyme)] (hfac = hexafluoroacetylacetonate, diglyme = bis(2-methoxyethyl)ether, Ln = La, Ce, Pr, Sm, Eu, Gd, Er, Lu) complexes are examined for providing evidence for the relevant role of f electrons in tuning the second-order NLO response dominated by the octupolar contribution. The lanthanide NLO chromophores have allowed a clean valuation of the affect of f electrons on the quadratic hyperpolarizability and on its dipolar and octupolar contributions.

In this report, GdPO4·nH2O and Tb3+-doped GdPO4·nH2O nanorods@silica-NH2 conjugated with IgG antibody were synthesized by applying hydrothermal, sol-gel, and coprecipitation methods successively. The effects of Tb3+/Gd3+ molar ratios of reactants on the size, morphology, and luminescence of the synthesized samples were also investigated. For the optimized GdPO4·nH2O : Tb3+ sample, uniform nanorods sizing from 10 to 30 nm in diameter and from 200 to 300 nm in length were obtained with the strongest luminescence in green color with narrow bands under the UV excitation (325 nm). The results revealed that, after being coated with silica-NH2 and conjugated with IgG antibody, all luminescence characteristic peaks of GdPO4·nH2O : Tb3+ corresponding to the process of energy transfer from Gd3+ to Tb3+ and then the emission from 5D4 → 7FJ (J=6,5,4,3) of Tb3+ were still clearly observed. The initial results of using the optimized Tb3+-doped GdPO4·nH2O nanorods@silica-NH2 conjugated with IgG antibody for rapid selective detection of Naja atra cobra venom were also reported. [ABSTRACT FROM AUTHOR]

The second-order nonlinear optical (NLO) properties of [Ln(hfac)3(diglyme)] (hfac = hexafluo- roacetylacetonate; diglyme = bis(2-methoxyethyl)ether; Ln = La, Ce, Pr, Sm, Eu, Gd, Er, Lu) complexes have been investigated by a combination of electric-field second harmonic generation (EFISH) and harmonic light scattering (HLS) techniques, providing evidence for the relevant role of I electrons in tuning the second- order NLO response dominated by the octupolar contribution. These lanthanide NLO chromophores allow a clean valuation of the influence of f electrons on the quadratic hyperpolarizability and on its dipolar and octupolar contributions. Molecular quadratic hyperpolarizability values measured by the EFISH method, βEFISH, initially increase rapidly with the number of f electrons, the value for the Gd complex being 11 times that of the La complex, whereas this increase is much lower for the last seven f electrons, the βEFISH value of the Lu complex being only 1.2 times that of the Gd complex. The increase of (βHLS), which is dominated by an octupolar contribution, is much lower along the Ln series. Remarkably, the good (βHLS) values of these simple systems, well known for their luminescence properties, are reached at no cost of transparency. [ABSTRACT FROM AUTHOR]

We present a visual tool and facile method to detect MCF-7 breast cancer cells by using YVO 4 :Eu 3+ @silica-NH-GDA-IgG bio-nanocomplexes. To obtain these complexes, YVO 4 :Eu 3+ nanoparticles with a uniform size of 10-25 nm have been prepared firstly by the hydrothermal process, followed by surface functionalization to be bio-compatible and conjugated with cancer cells. The YVO 4 :Eu 3+ @silica-NH-GDA-IgG nanoparticles exhibited an enhanced red emission at 618 nm under an excitation wavelength of 355 nm and were strongly coupled with MCF-7 breast cancer cells via biological conjugation. These bio-nanocomplexes showed a superior sensitiveness for MCF-7 cancer cell labelling with a detection percentage as high as 82%, while no HEK-293A healthy cells were probed under the same conditions of in vitro experiments. In addition, the detection percentage of MCF-7 breast cancer cells increased significantly via the functionalization and conjugation of YVO 4 :Eu 3+ nanoparticles. The experimental results demonstrated that the YVO 4 :Eu 3+ @silica-NH-GDA-IgG bio-nanocomplexes can be used as a promising labelling agent for biomedical imaging and diagnostics.