Absorption,fluorescence and resonance Rayleigh scattering spectral characteristics of interaction of gold nanoparticle with safranine T

Gold nanoparticle is an important nanomaterial and has been investigated widely owing to its special physical and chemical property[1―5]. In recent years it has been found that the multiple-component nano- structure assembly containing metal, semiconduct…     

Resonance Rayleigh scattering study of the interaction of bleomycinA<Subscript>5</Subscript> with nucleic acids and its analytical application

The interaction of bleomycinA5 with nucleic acids has been investigated by using resonance Rayleigh scattering (RRS), molecular absorption and fluorescence spectra. The result shows that in near pH 2.2 buffer medium and absence of any metal ions, nucleic acids are capable of binding with bleomycinA5 (BLMA5) to form complexes which can remarkably enhance the RRS intensity and result in bathochromic and hyperchromic molecular absorption of nucleic acids and fluorescence quenching of bleomycinA5. The RRS spectral characteristics for the binding products of bleomycinA5 with various DNA and RNA are similar, and the maximum RRS peaks are at 301 nm for ctDNA and sDNA, 370 nm for hsDNA, 310 nm for RNAtypeVI and RNAtypeIII, respectively. The increments of RRS intensity are greatly different in which DNA enhances greatly and RNA enhances lightly. In this work, the optimum conditions of the interaction and some influencing factors have been investigated. The reaction mechanism and a binding model for the interaction of BLMA5 with the nucleic acids are discussed. In addition, a highly sensitive, simple and rapid new method for the determination of DNA has been developed. The detection limits (3σ) are 5.7 ng/mL for ctDNA, 7.4 ng/mL for sDNA and 9.2 ng/mL for hsDNA, respectively. The method can be applied to determination of trace amounts of DNA.     

A study on the sizes and concentrations of gold nanoparticles by spectra of absorption, resonance Rayleigh scattering and resonance non-linear scattering

Liquid phase gold nanoparticles with different diameters and colors can be prepared using sodium citrate reduction method by controlling the amounts of sodium citrate. The mean diameters of gold nanoparticles are measured by transmission electron microscope (TEM). Gold nanoparticles with different sizes have specific absorption spectra. When the diameters of nanoparticles is between 12 and 41 nm, the maximum absorption peaks locate at 520-530 nm and there are red shifts gradually with the increase of diameters of gold nanoparticles. And when the size of gold nanoparticle is constant, the absorbance is proportional to the concentration of gold. Obvious resonance Rayleigh scattering (RRS) and the resonance non-linear scattering such as second-order scattering (SOS) and frequency-doubling scattering (FDS) appear at the same time as well, and the maximum scattering peaks are located at 286 nm (RRS), 480 nm (SOS) and 310 nm (FDS), respectively. When the concentration of gold is constant, absorbance and the intensities of RRS, SOS and FDS (I(RRS), I(SOS) and I(FDS)) have linear relationships with the diameters of gold nanoparticles. When the diameter of gold nanoparticle is constant, the absorbance and I(RRS), I(SOS), I(FDS) are directly proportional to the concentrations of gold nanoparticles. Therefore, it is very useful for studying the liquid phase gold nanoparticles by investigating the absorption, RRS, SOS and FDS spectra.     

曙红Y-Triton X-100疏水性氢键纳米微粒的吸收、荧光及共振瑞利散射光谱及其分析应用

在pH2.4～2.8的酸性介质中,曙红Y分子(H2L)取代水分子而与Triton X-100形成氢键缔合物.该疏水性的氢键缔合物,在水相的"挤压"作用和范德华力的作用下,能进一步聚集形成纳米微粒.此时将引起吸收光谱的变化和荧光猝灭,并导致共振瑞利散射(RRS)显著增强,为建立褪色分光光度法、荧光猝灭法和共振瑞利散射法测定Triton X-100创造了条件.三种方法均有较高的灵敏度.其中以RRS法灵敏度最高,对于Triton X-100的检出限为20.6ng/mL.本文研究了曙红Y与Triton X-100相互作用的适宜条件和对吸收、荧光和RRS光谱的影响.考察了共存物质的影响,表明方法有良好的选择性.发展和建立了灵敏、简便、快速测定Triton X-100的分光光度、荧光猝灭法和RRS新方法.文中还结合红外光谱、透射电子显微镜技术和量子化学方法对曙红Y-Triton X-100氢键缔合物及纳米微粒的形成以及对相应的光谱特性的影响进行了讨论,并研究了方法在环境分析中的应用.     

Study on the resonance Rayleigh scattering spectra and resonance non-linear spectra of congo red-amikacin system and its analytical application

The interaction between congo red (CR) and amikacin (AMK) was studied by resonance Rayleigh scattering (RRS), frequency doubling scattering (FDS) and second-order scattering (SOS) combining with absorption spectrum. In a weak acidic medium, CR combined with AMK to form an ion association complex with the composition ratio of 1∶1 by electrostatic interaction, hydrophobicity and charge transferring effect. As a result, the new spectra of RRS, FDS, and SOS appeared and their intensities were enhanced greatly. The maximum wavelengths of RRS, FDS and SOS were located at 563 nm, 475 nm and 940 nm, and the scattering intensities were proportional to the concentration of AMK. These three methods have very high sensitivities, and the detection limits were 4.0 ng·mL?1 for RRS, 3.6 ng·mL?1 for FDS and 1.9 ng·mL?1 for SOS, respectively. At the same time, the methods have better selectivity. A new method for the determination of trace amounts of AMK with congo red by resonance scattering technique has been developed. The recovery for the determination of AMK in blood serum and urine sample was between 95.5% and 105.5%. In this study, the properties, such as enthalpy of formation, charge distribution and mean polarizability, were calculated by AM1 quantum chemistry method. In addition, the reaction mechanism and the reasons for the enhancement of scattering spectra were discussed.     

Study on the absorption and fluorescence and resonance Rayleigh scattering spectra of Cu (II)-fluoroquinolone chelates with erythrosine and their applications

In pH 4.2-5.0 Britton-Robinson buffer solution medium, fluoroquinolone antibiotics (FLQs), such as ciprofloxacin (CIP), norfloxacin (NOR), ofloxacin (OF), levofloxacin (LEV), lomefloxacin (LOM), and sparfloxacin (SPA), react with Cu (II) to form chelate cations, which further bind with erythrosine to form the ion association complexes. They can result in the changes of the absorption spectra. Simultane- ously, erythrosine fades obviously and the maximum fading wavelength is located at 526 nm. The fad- ing reactions have high sensitivities. Thus, new spectrophotometries of determination for these drugs are developed. The ion-association reactions result in the quenching of fluorescence, which also have high sensitivities. The detection limits for six antibiotics are in the range of 7.1-12.2 μg·L?1. Furthermore, the reactions can result in the enhancement of resonance Rayleigh scattering (RRS). The maximum scattering peaks of six ion-association complexes are located at 566 nm, and there are two small RRS peaks at 333 nm and 287 nm. The detection limits for fluoroquinolone antibiotics are in the range of 1.70 -3.10 μg·L?1 for RRS method. Among the above three methods, the RRS method has the highest sen- sitivity. In this work, we investigated the spectral characteristics of the absorption, fluorescence and RRS, the optimum conditions of the reactions, and the properties of the analytical chemistry. In addi- tion, the mechanism of reactions were discussed by density function theory (DFT) and AM1 methods.     

共振瑞利散射光谱法测定饮料中日落黄

日落黄与壳聚糖盐酸盐发生缔合反应形成离子缔合物可使体系共振光显著增强。在1.0 mL pH 5.5的BR缓冲溶液中,该体系共振散射强度最大,反应可在室温5 min内迅速完成。在0.6～9μg.mL-1范围内散射强度(ΔI)与日落黄的浓度成正比,检出限为0.395μg.mL-1(n=5)。建立了一种简便、快速测定日落黄的方法,并成功用于饮料样品中日落黄含量的测定.加标回收率为93.0～101.8%,RSD为1.8～3.4%。     

Synthesis and crystal structure of a supramolecular adduct of the aqua nitrato complex of gadolinium [Gd(NO<Subscript>3</Subscript>)(H<Subscript>2</Subscript>O)<Subscript>7</Subscript>]<Superscript>2+</Superscript> with macrocyclic cavitand cucurbit[6]uril

A supramolecular adduct of gadolinium aqua nitrato complex and cucurbit[6]uril { [Gd(NO₃)(H₂O)₇](C₅H₅N)@(C₃₆H₃₆N₂₄O₁₂)}(NO₃)₂·10H₂O is obtained by slow diffusion of methanol into an aqueous solution containing gadolinium nitrate, pyridine, and cucurbit[6]uril. According to single crystal X-ray diffraction data, water molecules coordinated to metal atom make hydrogen bonds to polarized carbonyl groups of the macrocycle. The heptaaquanitratogadolinium(III) [Gd(NO₃)(H₂O)₇]²⁺ cation is structurally characterized for the first time. Crystal system is triclinic, space group \(P\overline 1 \), a = 12.3137(4) Å, b = 14.2334(5) Å, c = 19.5629(6) Å; α = 80.850(1)°, β = 86.879(1)°, γ = 68.855(1)°; V = 3157.15(18) ų, Z = 2. Oriented hydrogen-bonded chains of alternating cucurbit[6]uril molecules and gadolinium aqua cations form in the crystal structure.     

Resonance Rayleigh scattering, second-order scattering and frequency doubling scattering methods for the indirect determination of penicillin antibiotics based on the formation of Fe3[Fe(CN)6]2 nanoparticles

Under the HCl solution and heating condition, penicillin antibiotics such as amoxicillin (AMO), ampicillin (AMP), sodium cloxacillin (CLO), sodium carbenicillin (CAR) and sodium benzylpenicillin (BEN) could react with Fe(III) to produce Fe(II) which further reacted with Fe(CN)₆³⁻ to form a Fe₃[Fe(CN)₆]₂ complex. By virtue of hydrophobic force and Van der Waals force, the complex aggregated to form Fe₃[Fe(CN)₆]₂ nanoparticles with an average diameter of 45 nm. This resulted in a significant enhancement of resonance Rayleigh scattering (RRS) and non-linear scattering such as second-order scattering (SOS) and frequency doubling scattering (FDS). The increments of scattering intensity (ΔI) were directly proportional to the concentrations of the antibiotics in a certain range. The detection limits for the five penicillin antibiotics were 2.9–6.1 ng ml⁻¹ for RRS method, 4.0–6.8 ng ml⁻¹ for SOS method and 7.4–16.2 ng ml⁻¹ for FDS method, respectively. Among them, the RRS method exhibited the highest sensitivity and the AMO system was more sensitive than other antibiotics systems. Based on the above researches, a new highly sensitive and simple method for the indirect determination of penicillin antibiotics has been developed. It can be applied to the determination of penicillin antibiotics in capsule, tablet, human serum and urine samples. In this work, the spectral characteristics of absorption, RRS, SOS and FDS spectra, the optimum conditions of the reaction and the influencing factors were investigated. In addition, the reaction mechanism was discussed.     

Quantum-chemical study of C<Subscript>n</Subscript>F2<Subscript><Emphasis Type="Italic">n</Emphasis>+2</Subscript> conformers. Structure and IR spectra

Quantum-chemical calculations of the geometrical structure and vibrational spectra of C_nF_2n+2 oligomers (n = 5–8) in the chain and branched conformations are reported. The lengthening of the chain of C_nF_2n+2 does not substantially affect the geometrical parameters of the oligomers. In all cases under study, the most optimal structure of the molecule is a zigzag chain with bond lengths R(C-C) = 1.53 –1.54 and R(C-F) = 1.36 –1.34 ; the chain is rolled into a helix, which makes an angle of 17° with the plane. The IR spectra are sensitive to the structural deficiency of oligomers C_nF_2n+2 associated with the lateral trifluoromethyl groups formed in the chain; the spectra can be used for revealing defects of this type in the structure of polytetrafluoroethylene (PTFE). The possibility of defects associated with the lateral CF₃ groups in the structure of PTFE and its low-temperature modifications is explained based on the calculated total energies of C_nF2 _n+2.Original Russian Text Copyright © 2004 by L. N. Ignatieva, A. Yu. Beloliptsev, S. G. Kozlova, and V. M. BuznikTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 632–643, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Study on the interaction of trypsin with some DNAs and their analytical application by resonance Rayleigh scattering spectra

When trypsin reacts with Herring sperm DNA (hsDNA), Salmon sperm DNA (sDNA), and Calf thymus DNA (ctDNA) to form a complex, the resonance Rayleigh scattering (RRS) was remarkably enhanced and new RRS spectra appear. These new spectra have similar characteristics of RRS spectra. The maximum RRS peaks are at 307 nm (hsDNA, sDNA) and 290 nm (ctDNA), and other peaks are at 350 nm. The scattering intensity is proportional to the concentration of DNA or trypsin; so this intereaction can be used to determine trypsin using DNA or DNA using trypsin. In the determination of DNA using trypsin, the linear ranges for hsDNA, sDNA, and ctDNA are 0–2.3, 0–2.5, and 0–1.9 μg·mL⁻¹, and the detection limits are 0.4, 0.7, and 1.1 ng·mL⁻¹, respectively. In the determination of trypsin using hsDNA, the linear range is 0–30.0 μg·mL⁻¹, and the detection limit is 39.0 ng·mL⁻¹. In this paper, the intereaction conditions were optimized. The affecting factors, chemical properties of the complex, and the composition ratio of trypsin with DNA were investigated. Using trypsin as RRS probe, a sensitive method for the determination of trace amounts of DNA was developed. Translated from Chemical Journal of Chinese Universities, 2006, 27(3) (in Chinese)     

Crystal-chemical analysis of the structures of minerals with [Hg<Subscript>2</Subscript>]<Superscript>2+</Superscript> dumbbells

An analysis of the structures of minerals with [Hg₂]²⁺ dumbbells including poyarkovite [Hg₂]₃Cl₂O₂, shakhovite [Hg₂]₂Sb(OH)₃O₃, vasilyevite Hg₂₀O₆I₃Br₂Cl(CO₃), and kelyanite [Hg₂]₆[SbO₆]BrCl₂ was carried out. The determining factor in structure formation is the ordering of the centers of the cluster groups of mercury and large anions by systems of equidistant parallel planes with d _hkl ～ 2.5–4.5 Å. The different combinations of atoms and fragments in the structure are ordered by their own pseudotranslation lattices; this probably reflects the stages of crystallization. The crystal structures under study are examples of balance between the local interatomic interactions and the forces that create long-range order for different stoichiometries, masses, and sizes of components.     

Study on the interaction between diphenhydramine and erythrosin by absorption,fluorescence and resonance Rayleigh scattering spectra

In pH 4.5 Britton-Robinson(BR)buffer solution,erythrosin(ET)can react with diphenhydramine(DP)to form a 1:1 ion-association complex,which not only results in the change of the absorption spectra,but also results in the great enhancement of resonance Rayleigh scattering(RRS)and the quenching of fluorescence.Furthermore,a new RRS spectrum will appear,and the maximum RRS wavelength was located at about 580 nm.In this work,the spectral characteristics of the absorption,fluorescence and RRS,the optimum conditions of the reaction and the properties of an analytical chemistry were inves- tigated.A sensitive,simple and new method for the determination of DP by using erythrosin as a probe has been developed.The detection limits for DP were 0.0020μg/mL for RRS method,0.088μg/mL for absorption method and 0.094μg/mL for fluorophotometry.There was a linear relationship between the absorbance,RRS and fluorescence intensities and the drug concentration in the range of 0.0067-2.0, 0.29-6.4 and 0.31-3.2μg/mL,respectively.The effects of the interaction of diphenhydramine and erythrosin on the absorption,fluorescence and resonance Rayleigh scattering spectra were discussed. In light polarization experiment,the polarization of RRS at maximum wavelength was measured to be P =0.9779,and it revealed that the RRS spectrum of DP-ET complex consists mostly of resonance scat- tering and few resonance fluorescence.In this study,enthalpy of formation and mean polarizability were calculated by AM1 quantum chemistry method.In addition,the reaction mechanism and the rea- sons for the enhancement of scattering spectra and the energy transfer between absorption,fluores- cence and RRS were discussed.     

Calculations of IR-spectra of metastable bond isomers of ruthenium nitrosocomplexes [Ru(NO)Cl<Subscript>5</Subscript>]<Superscript>2−</Superscript> [Ru(NO)(CN)<Subscript>5</Subscript>]<Superscript>2−</Superscript> by DFT method

IR-spectra of stable and metastable isomers of ruthenium nitrosocomplexes, [Ru(NO)Cl₅]^2? and [Ru(NO)(CN)₅]^2?, have been calculated within the frames of density functional theory. Frequency assignment was refined on the base of analysis of normal vibration in internal vibrational coordinates. Calculation results confirm that spectrally observed metastable states are bond isomers with ν¹-ON and ν²-NO coordination.     

Resonance scattering spectral detection of ultratrace IgG using immunonanogold-HAuCl<Subscript>4</Subscript>-NH<Subscript>2</Subscript>OH catalytic reaction

Nanogold particles of 10 nm were used to label goat anti-human IgG (GIgG) to obtain nanogold-labeled GIgG (AuGIgG). In a citrate-HCI buffer solution of pH 2.27, AuGIgG showed a strong catalytic effect on the reaction between HAuCl₄ and NH₂OH to form big gold particles that exhibited a resonance scattering (RS) peak at 796 nm. Under the chosen conditions, AuGIgG combined with IgG to form immunocomplex AuGIgG-IgG that can be removed by centrifuging at 16000 r/min. AuGIgG in the centrifuging solution also showed catalytic effect on the reaction. On those grounds, an immunonanogold catalytic RS assay for IgG was designed. With addition of IgG, the amount of AuGIgG in the centrifuging solution decreased; the RS intensity at 796 nm (I _{796 nm}) decreased linearly. The decreased intensity ΔI _{796 nm} was linear with respect to the IgG concentration in the range of 0.08–16.0 ng · mL⁻¹ with a detection limit of 0.02 ng · mL⁻¹. This assay was applied to analysis of IgG in sera with satisfactory sensitivity, selectivity and rapidity. Supported by the National Natural Science Foundation of China (Grant No. 20667001), Natural Science Foundation of Guangxi Province (Grant No. 0728213), and the Foundation of New Century Ten-Hundred-Thousand Talents of Guangxi Province     

Binding equilibrium of I- to serum albumin with resonance Rayleigh scattering

The binding equilibrium between l- and human serum albumin (HSA) or bovine serum albumin (BSA) has been studied by means of the resonance Rayleigh scattering (RRS) and equilibrium dialysis. It has been found for the first time that RRS and multiple frequency scattering (MFS) are enhanced as the l- binding to the HSA and BSA, but fluorescence quenches. The equilibrium dialysis results suggest that the binding of l- to HSA and BSA fits a phase-distribution model other than Scsitchard model, and that the order of magnitude of its phase-distribution constant was found to be 104. It is most probable that Cl~ or other anion ions influence the binding of P by changing the ionic strength in the solution. The dialysis at different pH indicates that the binding mechanism is due to the electrostatic forces between the T-and protonated basic amino-acid residues.     

[1-B<Subscript>10</Subscript>H<Subscript>9</Subscript>N<Subscript>2</Subscript>]<Superscript>−</Superscript> and [1-CB<Subscript>9</Subscript>H<Subscript>10</Subscript>]<Superscript>−</Superscript> anions: an attempt of quantum chemical calculations

Comparative quantum chemical calculations of structural parameters, chemical shifts of ¹¹B NMR spectra, and atomic charges in 10-vertex boron hydride anions [1-CB₉H₁₀]⁻ and [1-B₁₀H₉N₂]⁻ were performed using the restricted Hartree-Fock method with the 6-31++G(D,P) basis set. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1853–1855, September, 2007.     

Study on the interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate by the resonance Rayleigh scattering, second-order scattering and frequency doubling scattering spectra and its analytical application

The interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate was investigated by ultravioletvisible absorption,resonance Rayleigh scattering(RRS),second-order scattering(SOS)and frequency doubling scattering (FDS)spectroscopy.In pH 5.3 Britton-Robinson(BR)buffer medium,chlorpromazine hydrochloride(CPZ)reacted with Pd(II) to form 2:1 cationic chelate,which further reacted with Na2WO4 to form a 1:1 ternary ion-association complex ([Pd(CPZ)2]·WO4).As a result,the signal intensities o...     

Electron interactions in the (η<Superscript>2</Superscript>-C<Subscript>60</Subscript>)Pd[P(Ph<Subscript>2</Subscript>)C<Subscript>5</Subscript>H<Subscript>4</Subscript>]<Subscript>2</Subscript>Fe complex

The electronic structure of the (η²-C₆₀)Pd[P(Ph₂)C₅H₄]₂Fe complex was calculated by the “hybrid” B3LYP method. Comparison of the experimental X-ray emission C-Kα spectrum and theoretical spectrum of the compound demonstrated that the electron interactions between the C₆₀ core, palladium atom, and organometallic fragment are described correctly in the framework of the quantum chemical method used. The electronic structure of the organometallic fullerene complex can be presented as a set of blocks of orbitals corresponding to different types of chemical bond. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2640–2644, December, 2005.     

The photodynamics of the [Ru(bpy)<Subscript>3</Subscript>]<Superscript>2+</Superscript> ion dopant in a solvent exposed silica sol–gel thin film

The [Ru(bpy)₃]²⁺ ion was encapsulated in a silica based sol–gel thin film, and the luminescence decay time constant of the photo-excited ³MLCT (metal-ligand-charge-transfer) was examined when this thin film was immersed in water, methanol, ethanol, 2-propanol, and glycerol. The luminescence decays of the films in the methanol, 2-propanol, and glycerol were better explained by a KWW model, while the luminescence decay of film immersed in water and ethanol were both well explained by a single exponential decay. Intriguingly, the dynamics of the dopants immersed in water, ethanol as well as in sol–gel bulk deviated from a single exponential fit and began to better explained by the the KWW model as temperature increased. The energy gap, ΔE(sol–gel film) and ΔE(solution), between the lowest ³MLCT state and atom localized ³ dd state for dopants under the presence of all solvents tested in this study were extracted from the temperature dependence study of the luminescence decay time constant. Generally, the ΔE(sol–gel film) values of ethanol and water were reduced from ΔE(solution), and ΔE(sol–gel film) value in all solvents matched the value of ΔE for sol–gel bulk. The effect on the dynamics in solvent over three weeks was investigated, and the films immersed in water presented the most remarkable monotonic increase in relaxation rates finally approaching the asymptotic value observed in the water solution. This phenomenon was considered to correspond to a trapping environment change due to a hydrophilic interaction through sequential intrusion of water or ethanol solvent into sol–gel pores.