Determination Of Trace Formaldehyde,Bismuth And Human Chorionic Gonadotropin By Nanogold/nanosilver RRS And SERS

The principle and application of resonance Rayleigh scattering spectroscopy and surface-enhanced Raman scattering spectroscopy were introduced.The analysis method research progress of formaldehyde,bismuth and human chorionic gonadotropin were summarized.The research content and significance of this paper were also reviewed.Determination of trace Formaldehyde based on Surface plasmo-resonan ce Rayleigh scattering energy transfer nano spectrumIn the alkaline condition,formaldehyde reacted with 4-amino-3-hydrazine-5-mercapto-1,2,4-triazole(AHMT)to form a purplish red compound 6-mercapto-S-triazole[4,3-b]S-tetrazole.When the compounds(as receptors)were close to the nanogold aggregates(as donors),the resonance Rayleigh scattering energy transfer(RRS-ET)took place,which resulted in the Rayleigh scattering signal quenching at 370 nm.With the increase of the concentration of formaldehyde,the formed compound increased,the scattering light energy of nanogold aggregates transferred to the purplish red compounds increased,so the Rayleigh scattering intensity decreased linearly at 370 nm.The quenching intensity responded linearly with the concentration of formaldehyde in 0.8-64 μmol/L.In the NH4Ac-HAc solutions condition,formaldehyde can react with acetyl acetone to form a yellow compound diacetyl dihydro-lutidine(DDL)in the presence of excess ammonium.When the compounds(as receptors)were close to the nanogold aggregates(as donors),the RRS-ET took place,which resulted in the Rayleigh scattering signal quenching at 370 nm.With the increase of the concentration of formaldehyde,the RRS intensity linearly reduced at 370 nm due to the energy transfer enhancement.Under the selected condition,with formaldehyde concentration increasing in 2.5-150μmol/L,and the RRS peak ΔI370 nm decreased linearly,and the linear regression equation was ΔI370 nm=21.24C+209.This method of surface plasmon RRS energy transfer(SPR-RRS-ET)was developed for the determination of trace formaldehyde,with satisfactory results.2 Hydride generation-resonance Rayleigh scattering energy transfer spectral method for the determination of trace BiIn the acidic solutions condition,Bi(Ⅲ)was reduced by NaBH4 to form BiH3 gas.Using I3--graphene oxide(GO)as absorption solution,the BiH3 gas reacted with I3-to form I-that resulted in the I3-concentration decreasing.In the absence of BiH3,the I3-concentration was high,the I3-as receptor was closed to the surfaces of GO as donors,the Surface plasmon resonance Rayleigh scattering energy of GO transferred to I3-heavily,which results in the resonance Rayleigh scattering(RRS)signal quenching severely.With the increase of the Bi(Ⅲ)concentration,the receptors concentration was decreased,and the RRS intensity enhanced linearly at 370 nm due to the RRS-energy transfer weakening.Under the selected condition,the RRS intensity was linear to the Bi(Ⅲ)concentration in 0.05-5.5 μmol/L,with the linear regression equation of ΔI370 nm=144.39C+70,with a detection limit of 4×10-3 mg/L.A new method of hydride generation-RRS energy transfer(HG-RRS-ET)spectroscopy was developed for the determination of trace Bi(Ⅲ).3 A novel nanocatalytic SERS detection of trace human chorionic gonadotropin using labeled-free Vitoria blue 4R as molecular probeIn the presence of pH 7.4 Na2HPO4-NaH2PO4 buffer solution and peptide probe solution,the AgNPs were aggregated to big AgNPs clusters that exhibited a strong resonance Rayleigh scattering(RRS)peak at 400nm.When the human chorionic gonadotropin(hCG)was present in solution,AgNPs do not aggregate that leads to the RRS peak at 400 nm intensity decreased.With the increase of the hCG concentration,the Rayleigh scattering intensity decreased linearly at 400 nm.The decreased RRS intensity(ΔI400 nm)is linear to hCG in the range of 0.25-50 ng/mL,with a regression equation of ΔI400 nm=27.4C+117,with a correlation coefficient of 0.9907.In the peptide reaction solution,the decentralized AgNPs had strong catalytic effect on the reaction of H2O2 and HAuCl4 generated gold nanoparticles.The reaction product gold nanoparticles exhibited a strong RRS peak at 370 nm and a strong SERS peak at 1615 cm-1.With the increase of the hCG concentration,the decentralized AgNPs concentration was increased,and the RRS intensity enhanced linearly at 370 nm due to the catalyst enhancing.The RRS intensity was linear to the hCG concentration in 0.05-10ng/mL,with the linear regression equation of ΔI370nm=409.8C+294,with a correlation coefficient of 0.9913.The Victoria blue 4R(VB4R)as surface enhanced Raman scattering(SERS)probe,the SERS intensity at 1615 cm-1 responds increased linearly with the hCG concentration in the range of 0.05-20 ng/mL,with the linear regression equation ofΔI1615 cm-1＝142C+134,with a correlation coefficient of 0.9871.Based on this,a new method of nanocatalytic SERS spectrum was proposed for the determination of trace hCG.