| Substance on nano-scale, exhibit unique physical, chemical and biological characteristics, some classical analytical means can not meet satisfactorly the requirement of study and determintion, therefore there is an urgent need to develop new methods. In recent years, new progress in characterizing nanoparticle and it's reaction product by absorption spectrum, fluorescence spectrum has been made, this provides useful means for nanoparticle study. With the development and futher study of analytical application of resonance Rayleigh scattering (RRS) and resonance non-linear scattering (RNLS), one find that nanoparticle, some organic compound and macrobiomoleule exhibit unique RRS and RNLS spectra characteristics, this made spectral analysis of this kind of technology become possible. As a new analytical method, resonance Rayleigh scattering has been developed quickly. Supported by the National Natural Science Foundation of China, this article investigates the process, mechanism and result of the reaction between the gold nanoparticles and some organic small molecular compounds at the molecule level with resonance Rayleigh scattering spectrum, and combining the transimisson electron microscope, uv-vis absorption and fluorescence spectrum and quantum chemical calculate method. First we investigated the corresponding relation between the sizes and concentrations of gold nanoparticles and spectrum of absorption, resonance Rayleigh scattering and resonance non-linear scattering. At the molecule level, then we investigated the interactions ofgold nanoparticle with some organic dye, drugs and cationic surfactants. The reaction mechanism has been inquired, and a model of the reaction has been put forward. RRS and RNLS, absorption spectrum, fluorescence spectrum, and relationship among the four spectra were investigated. The reason why RRS intensity increases greatly has been studied. Based on some simple, rapid and highly sensitive new methods for the determination of cation dye, aminoglycoside antibiotics, reloxifene (a new medicine) and cationic surfactants with gold nanoparticle as the RRS probes have been developed. Main investigated systems are listed as follow:1. A study on the sizes and concentrations of gold nanoparticles by spectra of absorption, resonance Rayleigh scattering and resonance non-linear scatteringLiquid phase gold nanoparticles with different diameters and colors can be prepared using sodium citrate reduction method by controlling the amounts of sodium citrate. The RRS, RNLS of the gold nanoparticles and the relationship between the diameters,sizes,concentrations,RRS and RNLS of the nanoparticles have been studied. The mean diameters of gold nanoparticles are measured by transmission electron microscope (TEM). Gold nanoparticles with different sizes have specific absorption spectrum. When the diameters of nanoparticles are between 12 nm and 41 nm, the maximum absorption peaks locate at 520 nm ~ 530 nm and there are bathochromic 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 intensitiesof RRS, SOS and FDS (/rrs, hos and 7FDs) have linear relationships with the diameters of gold nanoparticles. When the diameter of gold nanoparticle is constant, the absorbance and /RRS, hos, ^fds are directly proportional to the concentrations of gold nanoparticles. Therefore, it is very useful for studying gold nanoparticles in the liquid phase by investigating the absorption, RRS, SOS and FDS spectra.2. Study on the interaction between gold nanoparticle and some Basic dyes by resonance Rayleigh scattering (RRS), absorption and fluorescence spectraThe interaction between gold nanoparticle and basic phenazine dye (neutral red safraine T, phenosafranine), basic phenthiazine dye (Methylene blue, Toluidine blue, Azur B) and basic phenoxazine dye (Nile blue, Meldola's blue) has been studied with resonance Rayleigh scattering (RRS) spectrum, absorption and fluorescence spectra. In the pH 5 solution, citrate [(H2L)2*] self-assembl-es on the surface of positively-charged gold nanoparticle, which results in the [(Au)n(H2L)m]x" complex. In other words, one of carboxylate oxygen in (H2L) " moves inward and combines with gold nanoparticle. The other carboxylate oxygen moves outward to form a supermolecular complex anion with x negative charges. Then by virtue of electrostatic attraction, hydrophobic force and charge transfer action, the complex anion binds with dye cation to form a new ion-association complex. Here (H2L)2" acts as a bridge. The formation of the complex results in the significant enhancement of RRS intensity, the appearance of new RRS spectrum, the red shift of plasmon absorption band of gold nanoparticle as well as the decrease in the absorbance and fluorescence quenching for dye. In this work, the interaction between gold nanoparticle and dye on the RRS, absorption and fluorescence spectra has been investigated. The reason why RRS intensity increases greatly and the reaction mechanism have been inquired. The results show that RRS spectrum can not only be used to study nanoparticle and reaction product, but also is a sensitive means tocharacterize and detect nanparticles.The new method to detect some cationic dye(such as Methylene blue in blood serum) by RRS with the gold nanoparticle as probe has been studied and developed.3. Resonance Rayleigh scattering spectral method for the determination of some drugs and with gold nanoparticle as probe3.1 Determination of aminoglycoside antibioticsIn weak acidic medium, some aminoglycoside antibiotics, such as kanamycin (KANA), gentamicin (GEN) and tobramycin (TOB) can only produce very weak resonance Rayleigh scattering (RRS) signals, the RRS of gold nanoparticle is fairly strong, When aminoglycoside antibiotics assembles on the gold nanoparticle surface to form a supermolecular compound, RRS intensity is enhanced greatly and a new RRS spectrum appears. In a citrate containing solution, anion of citrate self-assembled on Au nanoparticle surface with positive charge, making Au nanoparticle become a supermolecular compound with negative charge surrounded by citrate. In a weak acid medium the supermolecular compound can combine with aminoglycoside antibiotics by virtue of electrostatic and hydrophobic interaction, forming aggregate with bigger diameters. The aggregate made plasmon absorption band of glod nanoparticle show evident bathochromic effect, resonance Rayleigh scattering (RRS) intensity be enhanced greatly and the resonance nonlinear scattering such as Frequency Double Scattering (FDS) and Second Order Scattering (SOS) can be increased markedly as well. In optimum conditions, there was a linear relationship between scattering intensity (A/) and the concentration of aminoglycoside antibiotics, and the highest sensitivity was RRS. So could gold nanoparticle be the RRS probe of high sensitivity for aminoglycoside antibiotics. The method has good selectivity and has been successfully applied to the detection of aminoglycoside antibiotics in clinic serum samples. In addition, the reaction mechanism and the reasons for the enhancement of RRS were discussed.3.2 Determination of reloxifeneThe first time that raloxifene hydrochloride (Ralo) marketed in America is on. March 1998, which is a kind of selective estrogen recepter modulators. The intensity of resonance Rayleigh scattering (RRS) of gold nanoparticle or Ralo is weak, but it can be enhanced significantly and a new RRS spectrum appears when both of them interact to form a supermolecular complex in acidic mediums. The intensity of RRS is directly proportional to the concentration of Ralo, So we can use RRS method to detect the content of reloxifene. This article studies the RRS spectrum character, the optimal reaction condition and the impacts among coexisting substance of this system. In another respect, this method has high sensitivity and fairly good selectivity. It's especially simple and rapid to measure the content of Ralo which is accurately poured into former emiction, and can get a high reclaim ratio.4. Study on the interaction between gold nanoparticle and cationic surfactants by resonance Rayleigh scattering spectrum and their analytical applicationsThe interactions of gold nanoparticle with three quaternary ammonium salt cationic surfactants (CS+) such as cetylpyridinium chloridize (CPC), Zephiramine (Zeph) and cetyl trimethylammonium bromide (CTAB) have been studied by Resonance Rayleigh scattering. The experiment shows that all of them can react with gold nanoparticle which result in a significant enhancement of RRS intensity, appearance of new RRS spectrum and absorption spectrum. An neutral medium is the optimum condition for the reactions, the RRS spectral characteristics of the reaction products are similar and their maximum scattering wavelengths ( X max) have slightly difference, 369 nm (Au-Zeph), 369 nm (Au-CPC), 341 nm (Au-CTAB) respectively. The intensities of RRS at X max of the complexes are directly proportional to the concentrations of CS+ in a certain range. The method has...
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