Biological Toxicities and Aggregation Effects of ʟ-Glycine and ʟ-Alanine Capped ZnS:Mn Nanocrystals in Aqueous Solution

Park, Sanghyun,Song, Byungkwan,Kong, Hoon Young,Byun, Jonghoe,Hwang, Cheong-Soo Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

In this study, water-dispersible ZnS:Mn nanocrystals were synthesized by capping the surface with conventional and simple structured amino acid ligands: $\small{L}$-Glycine and $\small{L}$-Alanine. The ZnS:Mn-Gly and ZnS:Mn-Ala nanocrystal powders were characterized by XRD, HR-TEM, EDXS, ICP-AES, and FT-IR spectroscopy. The optical properties were measured by UV-Visible and photoluminescence (PL) spectroscopy. The PL spectra for the ZnS:Mn-Gly and ZnS:Mn-Ala showed broad emission peaks at 599 nm and 607 nm with PL efficiencies of 6.5% and 7.8%, respectively. The measured average particle size from the HR-TEM images were $6.4{\pm}0.8$ nm (ZnS:Mn-Gly) and $4.1{\pm}0.5$ nm (ZnS:Mn-Ala), which were also supported by Debye-Scherrer calculations. In addition, the degree of aggregation of the nanocrystals in aqueous solutions were measured by a hydrodynamic light scattering method, which showed formation of sub-micrometer size aggregates for both ZnS:Mn-Gly ($273{\pm}94$ nm) and ZnS:Mn-Ala ($233{\pm}34$ nm) in water due to the intermolecular attraction between the capping amino acids molecules. Finally, the cytotoxic effects of ZnS:Mn-Gly and ZnS:Mn-Ala nanocrsystals over the growth of wild type E. coli were investigated. As a result, no toxicity was shown for the ZnS:Mn-Gly nanocrystal in the colloidal concentration region from 1 ${\mu}g/mL$ to 1000 ${\mu}g/mL$, while ZnS:Mn-Ala showed significant toxicity at 100 ${\mu}g/mL$.

Biological Toxicities and Aggregation Effects of L-Glycine and L-Alanine Capped ZnS:Mn Nanocrystals in Aqueous Solution

Sanghyun Park,Byungkwan Song,Hoon Young Kong,Jonghoe Byun,Cheong-Soo Hwang 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

In this study, water-dispersible ZnS:Mn nanocrystals were synthesized by capping the surface with conventional and simple structured amino acid ligands: L-Glycine and L-Alanine. The ZnS:Mn-Gly and ZnS:Mn-Ala nanocrystal powders were characterized by XRD, HR-TEM, EDXS, ICP-AES, and FT-IR spectroscopy. The optical properties were measured by UV-Visible and photoluminescence (PL) spectroscopy. The PL spectra for the ZnS:Mn-Gly and ZnS:Mn-Ala showed broad emission peaks at 599 nm and 607 nm with PL efficiencies of 6.5% and 7.8%, respectively. The measured average particle size from the HR-TEM images were 6.4 ± 0.8 nm (ZnS:Mn-Gly) and 4.1 ± 0.5 nm (ZnS:Mn-Ala), which were also supported by Debye-Scherrer calculations. In addition, the degree of aggregation of the nanocrystals in aqueous solutions were measured by a hydrodynamic light scattering method, which showed formation of sub-micrometer size aggregates for both ZnS:Mn-Gly (273 ± 94 nm) and ZnS:Mn-Ala (233 ± 34 nm) in water due to the intermolecular attraction between the capping amino acids molecules. Finally, the cytotoxic effects of ZnS:Mn-Gly and ZnS:Mn-Ala nanocrsystals over the growth of wild type E. coli were investigated. As a result, no toxicity was shown for the ZnS:Mn-Gly nanocrystal in the colloidal concentration region from 1 μg/mL to 1000 μg/mL, while ZnS:Mn- Ala showed significant toxicity at 100 μg/mL.

Mn-doped ZnS 결정의 광학적 특성

방태환,최성휴 한국물리학회 2013 새물리 Vol.63 No.9

ZnS:Mn crystals have a hexagonal structure based on the X-ray diffraction analysis. The lattice constants were a = 3.822 °A and c = 6.256 °A for the ZnS:Mn crystal. The optical absorption spectrum near the fundamental absorption edge showed that this crystal has a direct energy band gap. The direct and the indirect energy band gaps are given by Egd = 3.488 eV and Egi = 3.133 eV at 300 K, respectively. The photoluminescence spectrum of the ZnS:Mn crystal was measured in the wavelength range of 300 nm 850 nm at 300 K, and a high intensity emission peak due to the Mn2+ ion was observed near 583.6 nm. This PL peak was attributed to a radiative transition between the split electron energy levels of the Mn2+ ion occupying the Td symmetry site of the ZnS:Mn crystal host lattice.. ZnS:Mn 결정을 성장하여 성장된 결정의 구조와 격자상수 및 광학적에너지 간격 그리고 광발광 특성을 조사하였다. 성장된 결정은 hexagonal 구조이며 ZnS:Mn 격자상수를 구하면 a = 3.822 °A 이었다. 이 결정의 광흡수 spectrum은 측정시료의 온도를 300K로 유지하고, 300 $\sim$ 900 nm 파장영역에서 측정하였다. 기초 흡수단영역인 355 nm에서 급격한 광흡수가 나타났으며 측정된 광흡수스펙트럼으로부터 계산한 ZnS:Mn 결정의 직접전이 에너지 간격은 Egd = 3.488 eV , 간접전이 에너지 간격 Egi = 3.133 eV이었다. 광발광 특성 스펙트럼으로부터 443.1 nm 영역에서 ZnS 결정에 의한광발광 피크, 그리고 583.6 nm 영역에서 Mn을 첨가한 ZnS:Mn 결정에 의한광발광 피크가 나타났다. 583.6 nm 광발광 peak는 ZnS:Mn 결정에서zinc와 치환된 Mn이 Td symmetry site에 Mn2+ 이온으로 위치하고분리된 Mn2+ 이온의 에너지 준위사이의 radiative transition에기인한 peak다.

SYNTHESIS AND PHOTOLUMINESCENCE OF WATER-SOLUBLE ZnS:Mn^(2+)/ZnS QUANTUM DOTS BY NUCLEATION DOPING STRATEGY

ZHANGSEN YU,XIYING MA 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.1

We report the synthesis of luminescent-doped core/shell quantum dots (QDs) of water-soluble manganese-doped zinc sulfide (ZnS:Mn^(2+)/ZnS). QDs of ZnS:Mn^(2+)/ZnS were prepared by nucleation doping strategy, with thioglycolic acid (TGA) as stabilizer in aqueous solution. Structure and optical properties of the ZnS:Mn^(2+)/ZnS core/shell quantum dots were characterized by X-ray diffraction and photoluminescence emission spectroscopy. The influence of the synthesis conditions on the luminescent properties of ZnS:Mn^(2+)/ZnS QDs is discussed. Different Mn^(2+) concentrations, ratios of the TGA/(Zn+Mn) and thickness of the ZnS shell were used. Results showed that the ZnS:Mn^(2+)/ZnS QDs are water-soluble and have improved fluorescence properties. Therefore, Mn^(2+)-doped ZnS quantum dots could be potential candidates as fluorescent labeling agents in biology.

Syntheses and Characterizations of Serine and Threonine Capped Water-Dispersible ZnS:Mn Nanocrystals and Comparison Study of Toxicity Effects on the growth of E. coli by the Methionine, Serine, Threonine, and Valine Capped ZnS:Mn Nanocrystals

Lim, Eun-Ju,Park, Sang-Hyun,Byun, Jong-Hoe,Hwang, Cheong-Soo Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

Water-dispersible ZnS:Mn nanocrystals were synthesized by capping the surface of the nanocrystals with conventional aminoacids ligands: serine and threonine. The aminoacids capped ZnS:Mn nanocrystal powders were characterized by XRD, HR-TEM, EDXS, ICP-AES and FT-IR spectroscopy. The optical properties were also measured by UV/Vis and solution photoluminescence (PL) spectroscopies in aqueous solvents. The solution PL spectra showed broad emission peaks around 600 nm with PL efficiencies of 9.7% (ZnS:Mn-Ser) and 15.4% (ZnS:Mn-Thr) respectively. The measured particle sizes for the aminoacid capped ZnS:Mn nanocrystals by HR-TEM images were about 3.0-4.0 nm, which were also supported by Debye-Scherrer calculations. In addition, cytotoxic effects of four aminoacids capped ZnS:Mn nanocrsystals over the growth of wild type E. coli were investigated. Although toxicity in the form of growth inhibition was observed with all the aminoacids capped ZnS:Mn nanocrystals at higher dose (1 mg/mL), ZnS:Mn-Met and ZnS:Mn-Thr appeared non-toxic at doses less than 100 ${\mu}g$/mL. Low biological toxicities were seen at doses less than 10 ${\mu}g$/ mL for all nanocrystals.

Syntheses and Characterizations of Serine and Threonine Capped Water-Dispersible ZnS:Mn Nanocrystals and Comparison Study of Toxicity Effects on the growth of E. coli by the Methionine, Serine, Threonine, and Valine Capped ZnS:Mn Nanocrystals

임은주,박상현,변종회,황청수 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

Water-dispersible ZnS:Mn nanocrystals were synthesized by capping the surface of the nanocrystals with conventional aminoacids ligands: serine and threonine. The aminoacids capped ZnS:Mn nanocrystal powders were characterized by XRD, HR-TEM, EDXS, ICP-AES and FT-IR spectroscopy. The optical properties were also measured by UV/Vis and solution photoluminescence (PL) spectroscopies in aqueous solvents. The solution PL spectra showed broad emission peaks around 600 nm with PL efficiencies of 9.7% (ZnS:Mn-Ser) and 15.4% (ZnS:Mn-Thr) respectively. The measured particle sizes for the aminoacid capped ZnS:Mn nanocrystals by HR-TEM images were about 3.0-4.0 nm, which were also supported by Debye-Scherrer calculations. In addition, cytotoxic effects of four aminoacids capped ZnS:Mn nanocrsystals over the growth of wild type E. coli were investigated. Although toxicity in the form of growth inhibition was observed with all the aminoacids capped ZnS:Mn nanocrystals at higher dose (1 mg/mL), ZnS:Mn-Met and ZnS:Mn-Thr appeared non-toxic at doses less than 100 μg/mL. Low biological toxicities were seen at doses less than 10 μg/ mL for all nanocrystals.

Preparation and characterization of ZnS based nano-crystalline particles for polymer light-emitting diodes

Hwang, Jeong-mi,Oh, Mi-Ok,Kim, Il,Lee, Jin-Kook,Ha, Chang-Sik Elsevier 2005 Current Applied Physics Vol.5 No.1

<P><B>Abstract</B></P><P>Nano-crystalline ZnS:Mn and its derivatives are promising as a novel luminescent center because of its high quantum efficiency at room temperature. In this work, three different kinds of ZnS based nano-crystalline particles were synthesized and characterized in order to be utilized for polymer light-emitting diodes; ZnS:Mn, ZnS:CuCl, and ZnS:AgCl. Some of the ZnS based nanocrystals were either hybridized with poly(acrylic acid)(PAA) or doped to poly(9-vinyl carbazole)(PVCz)). The XRD analysis showed that the diameter of the ZnS based particles was in the range of 11.8–23.4 nm. In all the ZnS based nanocrystals hybridized with PAA, the photoluminescence (PL) was enhanced in comparison to the ZnS:Mn regardless of the metal ion. It was found that the ZnS:AgCl hybridized with PAA showed the highest PL and the ZnS:CuCl hybridized with PAA showed the lowest PL among the three ZnS based nanocrystals hybridized with PAA. The PL of PVCz doped with the ZnS based nanocrystals, however, was lower in comparison to the ZnS:Mn regardless of the metal ion though the differences were not large.</P>

White Light Emission from a Colloidal Mixture Containing ZnS Based Nanocrystals: ZnS, ZnS:Cu and ZnS:Mn

Lee, Jae Woog,Hwang, Cheong-Soo Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.1

Water dispersible ZnS based nanocrystals: ZnS (blue), ZnS:Cu (green) and ZnS:Mn (yellow-orange) were synthesized by capping the surface of the nanocrystals with a mercaptopropionic acid (MPA) molecule. The MPA capped ZnS based nanocrystal powders were characterized by using XRD, HR-TEM, EDXS, FT-IR, and FT-Raman spectroscopy. The optical properties of the colloidal nanocrystals were also measured by UV/Vis and photoluminescence (PL) spectroscopies in aqueous solvents. The PL spectra showed broad emission peaks at 440 nm (ZnS), 510 nm (ZnS:Cu) and 600 nm (ZnS:Mn), with relative PL efficiencies in the range of 4.38% to 7.20% compared to a reference organic dye. The measured average particle sizes from the HR-TEM images were in the range of 4.5 to 5.0 nm. White light emission was obtained by mixing these three nanocrystals at a molar ratio of 20 (ZnS):1 (ZnS:Cu):2 (ZnS:Mn) in water. The measured color coordinate of the white light was (0.31, 0.34) in the CIE chromaticity diagram, and the color temperature was 5527 K.

White Light Emission from a Colloidal Mixture Containing ZnS Based Nanocrystals: ZnS, ZnS:Cu and ZnS:Mn

Jae-Woog Lee,Cheong-Soo Hwang 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.1

Water dispersible ZnS based nanocrystals: ZnS (blue), ZnS:Cu (green) and ZnS:Mn (yellow-orange) were synthesized by capping the surface of the nanocrystals with a mercaptopropionic acid (MPA) molecule. The MPA capped ZnS based nanocrystal powders were characterized by using XRD, HR-TEM, EDXS, FT-IR, and FT-Raman spectroscopy. The optical properties of the colloidal nanocrystals were also measured by UV/Vis and photoluminescence (PL) spectroscopies in aqueous solvents. The PL spectra showed broad emission peaks at 440 nm (ZnS), 510 nm (ZnS:Cu) and 600 nm (ZnS:Mn), with relative PL efficiencies in the range of 4.38% to 7.20% compared to a reference organic dye. The measured average particle sizes from the HR-TEM images were in the range of 4.5 to 5.0 nm. White light emission was obtained by mixing these three nanocrystals at a molar ratio of 20 (ZnS):1 (ZnS:Cu):2 (ZnS:Mn) in water. The measured color coordinate of the white light was (0.31, 0.34) in the CIE chromaticity diagram, and the color temperature was 5527 K.

백색 LED의 특성에 대한 ZnS:Mn, Dy 황색 형광체의 영향

신덕진,유일,Shin, Deuck-Jin,Yu, Il 한국재료학회 2011 한국재료학회지 Vol.21 No.6

ZnS:Mn, Dy yellow phosphors for White Light Emitting Diode were synthesized by a solid state reaction method using ZnS, $MnSO_4{\cdot}5H_2O$, S and $DyCl_3{\cdot}6H_2O$ powders as starting materials. The mixed powder was sintered at $1000^{\circ}C$ for 4 h in an air atmosphere. The photoluminescence of the ZnS:Mn, Dy phosphors showed spectra extending from 480 to 700 nm, peaking at 580 nm. The photoluminescence of 580 nm in the ZnS:Mn, Dy phosphors was associated with $^4T_1{\rightarrow}^6A_1$ transition of $Mn^{2+}$ ions. The highest photoluminescence intensity of the ZnS:Mn, Dy phosphors under 450 nm excitation was observed at 4 mol% Dy doping. The enhanced photoluminescence intensity of the ZnS:Mn, Dy phosphors was explained by energy transfer from $Dy^{3+}$ to $Mn^{2+}$. The CIE coordinate of the 4 mol% Dy doped ZnS:Mn, Dy was X = 0.5221, Y = 0.4763. The optimum mixing conditions for White Light Emitting Diode was obtained at the ratio of epoxy : yellow phosphor = 1:2 form CIE coordinate.