Resonance Rayleigh Scattering And Fluorescence Analysis Of Iodide,Tea Polyphenols And E.coli

1 IntroductionThe principle and application of resonance Rayleigh scattering and fluorescence spectroscopy were introduced.The application of nanoparticles was also introduced.The research progress of iodide,Tea Polyphenols and E.coli were also reviewed.2 A Simple and Sensitive Graphene Oxide/gold Nanoparticle Surface Plasmon Resonance Rayleigh Scattering-Energy Transfer Analytical Platform for Detection of IodideIn pH 2.8 Na2HPO4-citric acid buffer solutions containing KI,the graphene oxide/gold nanoparticles(GO-AuNPs)were aggregated to big GO-AuNPs aggregations that exhibited a strong resonance Rayleigh scattering(RRS)peak at 370 nm.When KIO3 added,it reacted with KI to form I3-ions that adsorbed on the GO-AuNPs surfaces.The RRS intensity at 370 nm decreased due to the RRS energy of GO-AuNPs transferred to the receptors I3-ions.So,a simple and sensitive graphene oxide/nanogold surface plasmon resonance(SPR)Rayleigh scattering-energy transfer analytical platform was fabricated and can be utilized to detect trace KIO3.Under chosen conditions,the decreased RRS intensity(?I370nm)is linear to KIO3 concentration in the range of 0.025?5 pmol/L,with a regression equation of ?IRS=473.0C+94.0,with a detection limit of 8 nmol/L.Based on Vitamin C(VC)reducing I3-that led to the RRS enhancement,a 0.05?3 ?mol/L VC concentration can be detected.The iodate in salt samples was analyzed by this surface plasmon RRS energy transfer(SPRRS-ET)analysis platform,with satisfactory results.3 Silver Nanorod Surface Plasmon Resonance Rayleigh Scattering Energy Transfer Analytical Platform for Tea PolyphenolsThe stable silver nanorod(AgNR)sol in red was prepared by the two-step procedure of NaBH4-H2O2 and citrate heating reduction.The AgNR had a strong resonance Rayleigh scattering(RRS)peak at 346 nm.Ammonium Molybdate(AM)form yellow Organic Molybdate(OM)with Tea Polyphenols(TP)in pH 3.8 HAc-NaAc buffer solution.The receptor of OM closed to the donor of AgNR with strong SPR Rayleigh scattering,the RRS energy transfer exists and the RRS intensity at 370 nm decreased,owing to the overlap of AgNR RRS and OM absorption spectra.So,a simple and sensitive AgNR SPRRS-ET analytical platform was fabricated and can be utilized to detect trace TP.Under chosen conditions,the decreased RRS intensity(?I346nm)is linear to TP concentration in the range of 0.05?0.85 ?g/mL,with a detection limit of 0.03?g/mL.The TP in tea samples was analyzed by this surface plasmon RRS energy transfer analysis platform,with satisfactory results.4 A Sensitive Fluorescence Method for Detection of E.coli Using Rhodamine 6G DyeingIn pH 7.4 NaH2PO4-Na2HPO4 buffer solution,the negatively charged bacteria combined with positively charged alkaline dye rhodamine 6G(Rh6G)to dye by electrostatic interaction.The dyeing bacteria had a strong fluorescence peak at 552 nm.The fluorescence intensity was well linear to the Escherichia coli,Bacillus subtilis and Staphylococcus aureus concentration in the range of 7.06×104?3.53×107,5×105?2.475×108 and 32.5?16250 cfu/mL(colony forming unit/mL),with a detection limit of 3.2×104 cfu/mL of E.coli,2.3×105 cfu/mL B.subtilis and 16 cfu/mL S.aureus.By training 12 hours for samples,the detection of Escherichia coli linear range was 2?88 cfu/mL and this method was used for water and beverage analysis,with simple,rapid and sensitive advantages.