Applications Of Spectrum Methods In Environmental And Biochemistry Analysis

As important spectral analytical methods, the classical spectrofluorimetry and resonance Rayleigh scattering analysis method which has acquired rapid development in recent two decades play an important role in many research fields.The spectrofluorimetry has high sensitivity and good selectivity,while it requires special structure to emit fluorescence,which limits its application. The resonance Rayleigh scattering analysis has advantages of easy experiment operation and high sensitivity, but the disadvantage of it is poor selectivity. Moreover, the signals of fluorescence and scattering are easy to be effected by the conditions of instrument operation, sample medium and surrounding environment, so the stability and reproducibility has to be improved.As the future development and urgent requirement to application of spectrometer method,we should find new fluorescence and scattering probe and make some improvement or modification according to the limitation of the spectrum analysis.In this paper a dual wavelengt resonance light scattering (RLS) ratiometry was constructed for quercetin(Q T) detection successfully, according to the ratio of the increased and decreased light scattering signals, which are obtained by single scaning with common spectrofluorometer. Using dual wavelengt resonance light scattering (RLS)ratiometry improves the stability of cattering analysis and reduces the operation steps of dual wavelength ratiometry.When finding new fluorescence and scattering probe in the fields of environment and biochemistry, we make use of the reaction between BR buffer solution and lead ion to obtain increased scattering sigals and construct a very easy scattering analysis method for lead ion.Besides that, we design an aptamer probe with stern-loop structure,and take advantage of different fluorescence properties when small organic molecules dye Syber Green I react with single and double DNA to establish a simple, fast, sensitive analysis method for PrP.The main reseach content is as follows:(1)Using double-strand DNA specific fluorescence dye Syber Green I as fluorescence probe,we study the specific interaction of PrP and aptamer by fluorescence spectra.The experiments show that Syber Green I dye can be embedded in the stern of aptamer, which has a stern-loop structrue,and thus the fluorescence intensity of Syber Green I enhanced. With the addition of PrP, however, the interaction between PrP and aptamer destroied the stern-loop structure and lead to fluorescence quenching obviously. Between 3.69 and 516.6 nmol/L,the concentration of PrP has linear relationship with the intensity of fluorescence,and the linear equation is I_F=647.986-0.914x c_PrP, with the detection limit of 2.42 nmol/L (3σ).Therein a simple,fast and sensitive analysis method for PrP is established.(2)By the reaction between BR buffer solution and lead ion,we obtain scattering sigals by scaning spectrum with common spectrofluoromete, which has linear correlation to the concentration of lead ion, and a very easy scattering analysis method for lead ion is established.Compared with other determination methods for lead ion, the scattering analysis method has simpl BR-Lead system, easy controlled condition, low cost and high efficiency.(3)Using the interaction of quercetin (Q T) with Al³⁺ as an example, herein a dual wavelengt resonance light scat tering (RL S)ratiometry was constructed for Q T detection.In an acetate buffer solution,Al³⁺ formed a hydroxy complex,and with the addition of Q T, Al³⁺ was contested from the hydroxycomplex and preferential reaction between Al³⁺ and Q T occurred,displaying notable changes of RL S signals.Consequently, the RLS intensity of Al³⁺ hydroxy complex at 280nm decreased, while the RLS intensity of Al³⁺ -QT at 444 nm was enhanced remarkably. It was found that Log(I_RLS 280/444 nm) linearly decreased wit the Q T concent ration over the range of 215-25x10^-5 mol/L,with a detection limit of 215x10^-6mol/L.