A novel, simple and sensitive resonance scattering spectral method for the determination of chlorite in water by means of rhodamine B

A new resonance scattering method was proposed for the determination of chlorite, basing on the resonance scattering effect of rhodamine dye. In HCl-sodium acetate buffer solution, chlorite oxidizes 1- into 12 and the reaction of 12 and excess 1- results in If. It is respectively combined with rhodaminc dyes, including rhodamine B （RhB）, butyl rhodamine B （b-RhB）, rhodamine G （RhG） and rhodamine S （RhS）, to form association complex particles, which exhibit stronger resonance scattering （RS） effect at 400 nm. The chlorite concentration of ClO2 in the range of 0.00726-0.218 μg/ml, 0.0102-0.292 μg/ml, 0.00726-0.145 μg/ml and 0.0290- 0.174 μg/ml is respectively linear to the RS intensity of association complex particle systems at 400 nm for the RhB, b-RhB, RhG and RhS. The detection limits of the four systems were respectively 0.00436, 0.00652, 0.00580 and 0.01450μg/ml ClO2^-. In the four systems, the RhB system possesses good stability and high sensitivity. It has been applied to the analysis of chlorite in wastewater with satisfactory results.

A New Nanogold-Labeled Immunoresonance Scattering Spectral Probe for Determination of Trace IgG

A kind of 9 nm gold nanoparticles was prepared with the trisodium citrate and used to label goat anti-human IgG to obtain an IgG immunoresonance scattering spectral probe. In pH 5.8 buffer solution and in the presence of polyethylene glycol （PEG）, the immune reaction between gold-labeled goat anti-human IgG and IgG took place, and the resonance scattering intensity at 580 nm （I580nm） was enhanced greatly. The enhanced intensity AIRS is pro- portional to the IgG concentration from 1.3 to 1.5 X 10^3 ng.mL^-1, with a detection limit of 0.78 ng.mL ^-1. This assay showed high sensitivity and good selectivity for quantitative determination of IgG in human serum, with satisfactory results.

Simulation and analysis of ～(13)N+p elastic resonance scattering

The ^13 N＋p elastic resonance scattering has been studied at the secondary radioactive beam facility of CIAE in inverse kinematics via a thick-target method. The excitation function for the ^13N（p,p） scattering was obtained in the energy interval of Ecru ≈0.5-3.2 MeV with a ^13 N secondary beam of （47.8±1.5） MeV. Careful analysis of the secondary beam components and extensive Monte-Carlo simulations enable the resolution of the experimental proton spectra. The resonance parameters for five low-lying levels in ^14 O were deduced by Rmatrix fitting calculations with MULTI7 and SAMMY-M6-BETA. The present results show general agreement with those from a recent similar work, and thus confirm the observation of a new 0^- level at 5.7 MeV in 140 with an improved width of 400（45） keV.

A New and Sensitive Catalytic Resonance Scattering Spectral Assay for the Detection of Laccase Activity Using H2O2-1-TDMAC System

In pH 3.8 acetic acid-sodium acetate （HAC-NaAC） buffer solution, laccase exhibited a strong catalytic effect on the H2O2 oxidation of I- to form I2, and I2 combined with excess I- to form I3- that reacted with cationic surfactants of tetradecyl dimethylbenzyl ammonium chloride （TDMAC） to produce the （TDMAC-I3）n association complex particles, which exhibited a strong resonance scattering （RS） peak at 468 nm. Under the chosen conditions, as the concentration of laccase activity increased, the RS intensity at 468 nm （1468 nm） increased linearly. The increased RS intensity A1468 nm was linear to laccase activity in the range of 0.08-0.96 U/mL, with a regression equation of △1468 nm =88.8 U-1.9, and a detection limit of 0.02 U/mL laccase. This proposed method was applied to detect laccase activity in waste water, with satisfactory results.

Relanon between singularity expansion method(SEM) and resonance scattering theory(RST)

In recent years there are two theories for the acoustic scattering, one is the Singularity Expansion Method (SEM) , the other is the Resonance Scattering Theory (RST). In this paper, relation between these two theories was established. For the examples of the acoustic scattering from the solid elastic cylinder and sphere immersed in water, we prove that the RST can be directly derived from the SEM, so that these two theories are equivalent. By use of the Mittag- Leffler theorem we expand the pure elastic scattering wave, which is extracted by isolating the rigid background from the total scattering wave, in an exact resonance expansion. We specially prove that the reradiation efficiency and the resonance width are nearly proportional to the imaginary part of the corresponding pole for most solid objects immersed in water. This shows that the resonance scattering behavious can be entirely determined by the complex frequency poles. For the cases of an aluminum cylinder and a tungsten carbide sphere immersed in water, we calculate the partial-wave form functions by using the new resonance formulae. The results agree with the exact calculation well.

Resonance Scattering Detection of Trace Hg2＋ Using Aptamer-modified AuPd Nanoalloy Probe as Catalyst

The 5 nm AuPd nanoalloy in mole ratio of Au：Pd=32 ： 1 was prepared, using sodium citrate as the stabilizing agent and NaBH4 as the reductant. The AuPd nanoalloy was modified by the aptamer to prepare an aptamer- AuPd （AptAuPd） probe for resonance scattering （RS） detection of 5.（Y-1250 nmol/L Hg2＋. The AptAuPd-Hg2＋ aptamer reaction solution was filtrated by membrane, and the AptAuPd in the filtrate exhibited strong catalytic ef- fect on the slow NiP particle reaction between NiCI2 and NaHzPO2, and the NiP particles showed a RS peak at 508 nm. The RS intensity decreased when Hg2＋ concentration increased. The decreased RS intensity was linear to Hg2＋ concentration in the range of 0.5--1250 nmol/L. The RS assays were used to determine Hg2＋ in real samples, with good results.

A Simple and Sensitive Label-free Immunoassay for Factor B Using Resonance Scattering Spectral Detection

In pH 7.2 Na2HPO4-NaH2PO4 buffer solution and in the （GABF） was combined with human factor B （BF） specifically, presence of PEG-6000, goat-anti-human factor B and aggregated to form immune complex particles that exhibited a resonance scattering （RS） peak at 400 nm. The laser scattering indicated that the average diameter of immune complex particles was 1320 nm. BF in the concentration range of 0.04 to 9.60 μg/mL was proportional to the resonance scattering intensity at 400 nm. Its regression equation was A/=33.61C ＋ 1.4, with a correlation coefficient of 0.9969, and a detection limit of 0.01 μg/mL BF. This label-free resonance scattering spectral （RSS） method has been applied to the determination of BF in serum samples, and the results were in agreement with that of the immunoturbity.

Pure elastic resonance scattering of an obliquely incident plane acoustic wave by a submerged infinite cylinder

Although sound scattering by submcrged elastic cylinders was extensively studied,only a few works aimed at the case of obliquely incidence. In this paper, we derive a simple and explicit expression of the pure clastic resonance scattering function of a submerged infinite cylinder excited by a plane wave at obliquely incidcnce. For backscattering of a solid aluminum cylinder we calculated (a) the partial resoriance spectra n=0 to 7, (b) the far field total form functions and the pure elastic resonance form the functions, (c) the complex resonance poles in the normalized complex frequency plane and (d) the dispersion curves of the first several families of helical waves, at various incident angles in details. It was discussed that the generation mechanism and properties of the complementary resonance modes are existed only at oblique incidence. Our attention is also focused on the variance of the resonance spectra with the incident angle, particularly near several critical angles.

Pure elastic resonance scattering for submerged elastic objects with separable geometries

Theoretically, the extraction of resonance scattering spectra is performed by a pure elastic scattering function, which is defined as the total scattering function subtracts an appropriate background term. In this paper, we derive a simple and explicit expression of the pure elastic scattering function for the separable geometries immersed in water. It depends on the modal mechanical impedance and acoustic impedance except a phase factor only relative to the geometry Analyses used the new expression leads to two Kinds of resonances with distinguishable character: the elastic-borne wave resonances and the fluid-borne wave resonances. The former depends mainly on elasticity of the object and the fiuid-loading has secondary effect. The later is related closely with the liquid-loading and vanishes if the liquidloading vanishes. This allows us to classify the family of individual resonance correctly. Taking into account the contributions of the fluid-borne wave resonances, we modify the conventional resonance scattering formula by use of the Singularity Expansion Method.

The resonance scattering of underwater elastic cylinders

If the frequency of the incident sound wave coincides with one of the eigenfrequencies of the underwater elastic cylinder, the corresponding eigenvibration will be excited by incident sound wave and strongly reradiate sound wave towards surronding water. It has been revealed by previous investigations that the amplitude of backscattering sound appears to be minimum at the eigenfrequencies of the underwater metallic cylinders because of the destructive interference between reradiated wave of the eigenvibration and the geometrical reflected wave from surface of the cylinders. In this paper, a new phenomenon has been revealed. The amplitude of backscattering sound appears to be maximum at the eigenfrequencies of a cylinder made from nonmetallic material in which the velocity of elastic transverse wave is less than the sound velocity in water.

Resonance Scattering Spectral Determination of HSA with a New Scattering Enhanced Reagent of K_3[Fe(CN)_6]

A new resonance scattering spectral (RSS) method for the determination of human serum album (HSA) has been proposed with the resonance scattering enhanced reagent of K 3[Fe-(CN) 6]. In the medium of HCl (2.0×10 -3 mol/L), HSA may combine with 3- by intermolecular forces (mainly by electrostatic force) to form { 3- n-HSA m+} k nanoparticle of the ion-association complexes of HSA m+- 3- n. There is a strongest resonance scattering intensity at 351 nm, owing to the existence of the resonance scattering of the nanoparticle, 3- molecular absorption and the non-distribution of the emission intensity of Xe lamp in the range of 200-1000 nm. In addition, two resonance scattering peaks at 470 and 700 nm were observed. The HSA concentration in the range of 0-12 μg/mL is linear to the resonance scattering intensity at 351 nm. The determination limit of this method is 0.1 μg/mL HSA, about ten-fold lower than that of Coomassie brilliant blue protein assay. This method has been used for the determination of HSA in human serum and synthetic samples with satisfactory results. The mechanism of enhanced resonance scattering light, the TEM of the particle, the concepts of quasi-elastic absorption and un-elastic absorption were also discussed.

Surface-enhanced resonance Raman scattering spectroscopy of single R6G molecules

Surface-enhanced resonance Raman scattering （SERRS） of Rhodamine 6G （R6G） adsorbed on colloidal silver clusters has been studied. Based on the great enhancement of the Raman signal and the quench of the fluorescence, the SERRS spectra of R6G were recorded for the samples of dye colloidal solution with different concentrations. Spectral inhomogeneity behaviours from single molecules in the dried sample films were observed with complementary evidences, such as spectral polarization, spectral diffusion, intensity fluctuation of vibrational lines and even ＂breathing＂ of the molecules. Sequential spectra observed from a liquid sample with an average of 0.3 dye molecules in the probed volume exhibited the expected Poisson distribution for actually measuring 0, 1 or 2 molecules. Difference between the SERRS spectra of R6G excited by linearly and circularly polarized light were experimentally measured.

Characterization of gold nanoparticle bioconjugation by resonance light scattering correlation spectroscopy

Gold nanoparticles （GNPs） have been widely used as probes and nanomaterials in certain biological and biomedical fields thanks to its special physical and chemical properties. However, it is still difficult to characterize GNPs-bioconjugates in solution, which has greatly limited further bioapplications of GNPs. In this study, we reported a single particle method for characterizing GNPs- biomolecules in solution using resonance light scattering correlation spectroscopy （RLSCS）. The interaction of GNPs with bovine serum albumin （BSA） and thiol-modified oligonucletides were investigated.

Selective Determination of Nanogram γ-Globulin in Human Blood Serum by Resonance Light Scattering of Functionalized NanoPbS

Functionalized nano-PbS has been prepared and characterized. The functionalized nanoparticles have good dispersibility in water. Reaction of functionalized nanoPbS with gglobulin (gIgG) results an enhanced resonance light scattering (RLS) around 385 nm. However, when the content of HSA is lower than 0.5 mg ml-1 the RLS enhancement is very weak and is nonlinear to concentration of HSA. Based on these results, a new direct quantitative determination method for gglobulin in blood serum samples without separation is established. Under optimal conditions, the enhanced RLS intensity is in proportion to the gIgG concentration in the range 10500 ng/mL. The limit of detection is 2.75 ng/mL. This method is proved to be very sensitive, rapid, simple and selective for detection of gIgG in blood serum.

Resonance Light Scattering Imaging Determination of Heparin

A laser-induced resonance light scattering （RLS） imaging method to determine heparin is described based on the high light scattering emission power of the aggregation species of heparin with α, β, γ, δ-tetra（4-trimethylaminoniumphenyl）prophyrin （TAPP） in solution, By imaging the light scattering signals of the aggregation species, we proposed the method to determine the heparin with a detection range of 0.02 - 0.6μg/mL and the detection limit （30） of 1.3 ng/mL.

Determination of sodium hyaluronate with some basic bisphenylnaphthylmethane dyes by resonance Rayleigh scattering method

In an acetic acid–sodium acetate buffer solution of pH 3.6–6.8, a compound complex was formed between sodium hyaluronate (abbreviated as SH) and some basic bisphenylnaphthylmethane dyes, leading to a great enhancement of the intensity of resonance Rayleigh scattering (RRS) and giving a new RRS spectrum, with its maximum scattering peak near 280 nm. It was also found that the intensity of RRS was directly proportional to the concentration of SH near the range between 0 and 3.0 mg/L. Based on these facts, a sensitive method for the determination of SH has been established. The method had good selectivity, and has been used for the determination of total amounts of SH in samples with satisfactory results. For the NB–SH system, the detection limit of SH was down to 13.7 ng/mL.

Resonance Light Scattering Spectra of Silver Thiocyanate System and its Application in Analysis

A novel determination method of Ag^＋ was established. In acetic acid-sodium acetate buffer （pH 5.0） medium, Ag^＋ reacts with SCN^- to form AgSCN in the presence of TritonX-100,which results in an increase of resonance light scattering （RLS）and giving a new RLS spectrum.The maximum RLS peak was at 585 nm,The enhancement of resonance light scattering at 585 nm was proportional to the concentration of Ag^＋ ranging from 0.0045-4.00μg mL^-1 （r=9991）,and the detection limit was 1.37 ng mL^-1 with the recovery of 97.70%- 104.80%。

Solution Properties of Mixed Starch/Chitosan Revealed by Resonance Light Scattering

The association behavior of starch and chitosan and the dilute solution properties of the starch/chitosan complex were investigated by means of resonance light scattering（RLS） spectra.The interaction between starch and chiotsan was proved by RLS.Based on the results,the appropriate association condition was selected.However,the solution property of starch/chitosan was affected greatly by external factors such as pH value and metal ionic strength.The change of pH,which causes the irreversible transition of solution from transparent into murky,provides some important information of partitioning behavior of the complex in solution.The durative enhancement of RLS intensity for the complex exhibited two inflexions and a plateau in the presence of a certain amount of Fe 3＋.It indicates that Fe 3＋ not only increases the RLS intensity,but also induces the micell-aggregate transition of the complex in solution.Moreover,the thermodynamic parameters for micell formation process at different temperatures,based on the RLS values,were calculated.

Resonance Light Scattering Method for Determination of Amikacin with Potassium Ferrioxalate as a Probe

In a weak acid medium, potassium ferrioxalate（PF） can react with some aminoglycoside（AGs） antibiotics, such as amikacin（AMK）, kanamycin（KANA）, tobramycin（TOB） and gentamicin（GEN）, to form ion-association complexes. It results in the enhancement of resonance light scattering（RLS） in different degrees. The maximum scattering peaks are all located at 345 nm. Among them, the relative scattering intensity（AIRLs） of AMK system is much higher than that of KANA, TOB or GEN. Therefore the method is more propitious to the determination of trace amounts of AMK. The optimum reaction conditions, influencing factors, and the relationship between scattering intensity and concentration of antibiotics were investigated by means of the proposed method. The enhancement of RLS signals is directly proportional to the concentration of antibiotics in a certain range of concentration. A new resonance light scattering method for the determination of AMK and other aminoglycoside antibiotics with [Fe（C2O4）3]^3- as a probe is thus established based on it. The method exhibits high sensitivity and good selectivity. The detection limit（3σ） for AMK is 1.8 ng/mL. The method can be applied to the determination of AMK in clinical serum samples. The reaction mechanism and the reasons for RLS enhancement are discussed in this paper.

Determination of Potassium Ferrocyanide in Foods by Resonance Rayleigh Scattering Method with Basic Triaminotriphenylmethane Dyes

In this work, a sensitive, rapid and simple method for the determination of trace amounts of potassium ferrocyanide in salinized foods and table salt using EV as a RRS probe is established. The detection limit （3σ） of the EV system is 7.8 ng/mL. This new method is more suitable for the determination of the trace amounts of potassium ferrocyanide in colour salinized foods and it can not be disturbed by the color of salinized foods.