Papers by Author: Ai Hui Liang

Abstract: In the media of pH 2.72 HCl-N_aA_c, Fe3O4 nanoparticles in size of 10 nm exhibited strong catalytic effect on the slow reaction of H₂O₂ and the substrate dopamine (DA) to form dark red small molecule polymer particles, which exhibited two absorption peaks at 305nm and 435nm. In the optimum conditions, as the concentration of H₂O₂ increased, the absorption value at 300 nm increased linearly. The increased absorption intensity (ΔA305nm) was linear to the H₂O₂ in the range of 0.5-35 μmol/L, with a linear regression equation of ΔA305nm=0.014C +0.043, a relative coefficient of 0.9997 and detection limit of 0.13 μmol/L H₂O₂, respectively. The proposed method was applied to detect H₂O₂ samples, with satisfactory results.

Abstract: In pH 6.6 Na2HPO4-citric acid buffer solution and in the presence of KCl, the nanosilver-labeled rabbit anti-hCG (Ag-RAhCG) was aggregated un-specifically to the aggregations. Upon addition of rhodamine 6G (RhG) molecular probe, it adsorb on the surface of Ag-RAhCG aggregations that exhibited the strongest surface-enhnaced resonance Raman scattering (SERRS) peak at 613 cm-1. In the optimal condition, the decreased SERRS intensity responds linearly with the concentration of hCG over 0.05-1.75 µg/mL. Based on this, a new and simple SERRS method has been proposed for the determination of hCG in serum samples, with satisfactory results.

Abstract: O₃ reacted with KI-H₃BO₃ absorption solution to produce I₂ which can combine with the excess I- to form I₃-. In pH 4.0 HAc-NaAc buffer solution, I₃- reacted with rhodamine 6G (Rh6G) to form Rh6G-I₃ association particles, which exhibited a great decreasing at 525 nm. Under the chosen conditions, the decreased intensity ΔA was linear to I₂ concentration in the range of 0.5×10^-6-33×10^-6 mol/L. Thus, a highly sensitive and selective spectrophotometric method was proposed to detect O₃ in the air, since the concentration of O₃ was equal to that of I₂ in this reacted system.

Abstract: Highly sensitive and selective surface-enhanced resonance Raman scattering (SERRS) spectral detection technique are developed by combining the functional nucleic acid (FNA) including aptamer and DNAzyme, and nanoparticle such as gold/silver (NG/NS) aggregation. The recent progress of SERRS was reviewed in this paper.

Abstract: In pH 6.6 Na₂HPO₄- citric acid buffer solution and in the presence of KCl, the immunoreaction between hCG and nanosilver-labeled anti-hCG took place, the immunonanosilver-complex was formed and deposited, caused the resonance Rayleigh scattering (RRS) intensity at 510 nm decreased. In the optimal condition, the decreased RRS intensity responds linearly with the concentration of hCG over 0.125-1.75 µg/mL. Based on this, a new and simple RRS method has been proposed for the determination of hCG in serum samples, with satisfactory results.

Abstract: Using sodium citrate as reducing agent, different sizes of gold nanoparticles(GN) were prepared, and were modified by platelet-derived growth factor (PDGF) aptamer to obtain stable aptamer-nanogold probes (Apt-GN). The probe specifically combined with PDGF-AA to form Apt-GN-PDGF-AA clusters that exhibited a resonance Rayleigh scattering (RRS) peak at 550 nm. The RRS intensity ΔI_550nm was linear to the PDGF-AA concentration in the range of 0.33-40 ng/ml. The probe has strong catalysis of the Fehling reagent-glucose Cu₂O particle reaction that can be monitored by RRS technique at 610 nm, but the cluster is very weak. When PDGF-AA concentration increased, the Apt-GN decreased, and the RRS intensity at 610 nm decreased. The decreased RRS intensity ΔI_610nm was linear to PDGF-AA concentration in the range of 0.03-26.67 ng/mL. Accordingly, two new aptamer-nanogold RRS methods were established.

Abstract: The Te particles appear two strong resonance Rayleigh scattering peak at 778 nm and 540 nm. In the HCl medium at 70 oC, rhenium (VII) or Re nanoparticles catalyze the Sn(II) reduction of Te(VI) to form Te particles. The RS intensity at 778 nm enhanced linearly with Re concentration. The enhanced RS intensity was linear Re concentration in the range of 0.01-2.0 nmol/L, with a detection limit of 0.005 nmol/L Re. This method was applied to analysis of Re in real sample, and the results were agreement with that of the spectrophotometry

Abstract: Cr(VI); dithiothreitol; Nanogold; Resonance Rayleigh scattering spectral assay. Abstract. Nanogold (NG) in size of 15 nm was prepared by sodium citrate procedure, and it was modified by 1,4-dithiothreitol (DTT) to form NG-DTT probe for Cr(VI). In diluted H2SO4 medium, the probe interacted with Cr(VI) to form big NG clusters that led to the resonance Rayleigh scattering (RS) peak at 720 nm increased greatly. Under the selected conditions, the increased RS intensity (ΔI720nm) is linear to Cr(VI) concentration in the range of 10-50 nmol/L, with a regression equation of ΔI720nm= 2.05 C-7.5, coefficient of 0.9989, and a detection limit of 5 nmol/L. This nanogold RS method was applied to determination of Cr(VI) in waste water samples, with satisfactory results.

Abstract: The Au/MnO2 nanoalloy in diameter of 10 nm were prepared, using sodium citrate as the stabilizing agent and NaHB4 as the reductant. An aptamer Au/MnO2 nanoprobe (Apt-Au/MnO2) for Hg2+ was prepared using the aptamer modified. In the pH 7.0 Na2HPO4-NaH2PO4 and NaCl, The nanoprobe reacted with Hg2+ to form double-stranded T-Hg2+-T mismatches, and the released Au/MnO2 nanoparticles aggregated to big particles, which induced an increase in the resonance scattering (RS) signal at 570 nm. The RS signal was linear to the concentration of Hg2+ in the range of 0.1-7.5 nmol/L, with detection limit of 0.06 nmol/L Hg2+. This aptamer modified nanoalloy RS method was applied to detect Hg2+ in water samples, with satisfactory results.

Abstract: The aptamer of platelet-derived growth factor (PDGF) was used to modified nanogold to obtain a stable aptamer-nanogold(Apt-NG) probe for PDGF. In the condition of pH 7.2 Na2HPO4-NaH2PO4 buffer solution and 5.33 mmol/L NaCl, the Apt-NG specifically combined with PDGF to form Apt-NG-PDGFA cluster that resulted in the resonance Rayleigh scattering (RRS) intensity at 550 nm. When the PDGF concentration increased, the nanogold aggregated (NGA) increased, and the RRS intensity at 550 nm increased. The increased RRS intensity ΔI550nm was linear to the PDGF concentration in the range of 3.33-40 ng/mL, with a regression equation of ΔI550nm=10.8 C-24.2, coefficient of 0.9932 and a detection limit of 0.53 ng/mL