Resonance Scattering Spectral And Spectrophotometric Analysed Trace Mercury,Urea And Cationic Surfactant

1 IntroductionCharacteristics and analytical application of gold nanoparticles in recent years were introduced.The analytical progress of composite nanoparticles,mercury,urea and cationic surfactant were also introduced.The basic theory and the application of resonance scattering spectra technology and the spectrophotometry were summarized.2 A high selectivity and good sensitivity rapid resonance scattering spectral method for detection of trace Hg2+ using aptamer-Au/MnO2 nanoalloy as probeThe deferent Molar ratio of Au/MnO2 nanocomposite particles were prepared by sodium borohydride procedure,which Characteristics of resonance scattering spectral were studied.Aptamer was used to modify Au/MnO2 nanoalloy particle to obtain a stable aptamer-Au/MnO2 nanoalloy probe(Apta-Au/MnO2).The probe is not aggregated in the pH 7.0 Na2HP04-NaH2PO4 buffer solution and in the presence of high concentration of NaCl.In the presence of Hgig,Hg2+ can interact with the probe to form double-stranded T-Hg2+-T mismatch material and to release Au/MnO2 nanoalloy particles from the probe.The released Au/MnO2 nanoalloy particles aggregated to form bigger clusters which led the resonance scattering(RS)intensity at 570nm enhanced linearly with the concentration of Hg2+.So a new resonance scattering spectral method with the advantages of high sensitivity,good selectivity and simplicity for rapid detecting Hg2+.Thirty two bases of Apta-Au/MnO2's regress equation is ?1570 nm-46.39 C + 9.7,linear range is 0.1-7.5 nM,detection limit is 0.06 nM Hg2+.3 A Novel and Senensitive Resonance Scattering Assay for Detection of Urea Coupling Urease Catalytic reaction and NH4+ Associated Particle ReactionIn the pH 6.6 Na2HPO4-NaH2PO4 buffer solution at 40? and in the presence of urease,urea was decomposed catalytically to form NH4+.The NH4+ reacted with sodium tetraphenyl boron(NaTPB)to association complex particles that exhibited a resonance scattering(RS)peak at 474mn.With the increase of urea concentration,the NH4+ increased,and the RS intensity at 474 nm enhanced linearly.Under the conditions chosen,the decreased RS intensity(?I474 nm)had a linear response to urea concentration in the range of 0.125-15 ?M,with a detection limit of 0.058?M urea,and regression equation of ?I474nm= 31.6 C+ 2.1,with a correlation coefficient of 0.9986.This catalytic RS method was applied for the detection of urea in human serum,the results were consistent with the reference method,with good selectivity and sensitivity.4 Spectrophotometry assay for detection of cationic surfactant coupling nanogold catalysis formic acid restore phosphomolybdic reacionIn the pH 7.4 Na2HPO4-NaH2PO4 buffer solution,the cationic surfactant(CS)combined with nanogold particles(AuNP),the Au nanoparticles aggregate,result in its color change from wine red to bluish violet.AuNP has a strong catalysis to methanoic acid-molybdophosphoric acid oxidation-reduction reaction,but aggregated AuNP's catalysis is weak,with the production molybdophosphoric blue have a absorbance peak at 700 nm.With the increase of CS concentration,the AuNPA increased,the AuNP in the reaction solution decreased,its catalyzed decreased,and the absorbance value at 700nm decreased linearly.The CS concentration had a good linear response to the absorbance value(?A700nm).When the Tetradecyl dimethyl benzyl ammonium chloride(TDBAC)concentration ranges between 6.25-250 nmol/L,the color absorption follows Beerps Law.The molar absorption coefficient is 2.2×106 L·mol-1·cm-1.When the Cetyl trimethyl ammonium Bromide(CTMAB)concentration ranges between 0.625-250 nmol/L,the color absorption follows Beerps Law.The molar absorption coefficient is 2.1×106 L·mol-1·cm-1.When the Dodecyldimethylbenzylammonium chloride(DDBAC)concentration ranges between 12.5-500 mol/L,the color absorption follows Beerps Law.The molar absorption coefficient is? 9×105 L ·mol-1 ·cm-1.So the spectrophotometric method for the determination of cationic surfactant with nanogold particles catalysing.This method was simplicity and cheapness,had high sensitivity comparing to the reported methods.