2004 Fiscal Year Final Research Report Summary
Development of Nanoparticle Probes for Molecular Imaging
| Project/Area Number |
15350083
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional materials chemistry
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| Research Institution | Kochi University |
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Principal Investigator |
WATANABE Shigeru Kochi University, Department of Material Science, Associate Professor, 理学部, 助教授 (70253333)
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| Co-Investigator(Kenkyū-buntansha) |
SHIOZAKI Hisayoshi Technology Research Institute of Osaka Prefecture, Researcher, 主任研究員 (40359336)
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| Project Period (FY) |
2003 – 2004
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| Keywords | gold nanoparticles / gold colloid / plasmon / nanoprobes / colorimetric detection / glucose / surface enhanced Raman scattering / 糖 |
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| Research Abstract |
Gold and silver nanoparticles have been of increasing interest in applications to biological and chemical nanosensors. Amide-functionalized gold nanoparticles (Amide Au-NP) have been prepared. The anion sensing properties of Amide Au-NP were investigated by UV-vis titrations. The addition of anions to a solution of Amide Au-NP in 0-1%DMSO/CH_2Cl_2 at 20℃ caused dramatic changes in the plasmon band. The marked decrease in extinction is due to anion-induced aggregation of Amide Au-NP. Δl_<max>=(l_<min> - l_0)/ (l_0 is plotted against the free energy of hydration ΔG^o_<0.1>(kcal mol^<-1>) in the gas phase for the anions as a measure of hydrogen-bond acceptor strength of the guest anions. There is a good correlation between Δl_<max> and ΔG^o_<0.1> for the anions. The preference for HSO_4^- and H_2PO_4^- over other anions indicates that the hydrogen-bond interaction of NHCO...HOX (X=S or P) significantly contributes to the anion recognition leading to nanoparticle aggregation. It is noted t
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hat the Amide Au-NP are capable of optically sensing changes in anion concentration at a level of 10^<-6>M. The detection limit is increased about three orders of magnitude higher than originally expected.
Thioglucose-capped gold nanoparticles (1-TG Au-NP) have been prepared by the chemical reduction of HAuCl4 using 1-thio-β-D-glucose (1-TG) as the reducing and capping agent. The 1-TG Au-NP could be well dispersed in the buffer solution at physiological pH. The colorimetric detection of halide anions and oxoanions was investigated using UV-vis spectroscopy in an aqueous solution of 10 mM HEPES buffer (pH 7.4) at 20℃. Addition of F^- to a solution of the 1-TG Au-NP causes a red shift in the surface plasmon band. Extinction at wavelengths above 600 nm corresponds to the collective plasmon resonance of closely spaced gold nanoparticles, indicating the anion-induced nanoparticle aggregation. DLS measurements also indicate the size distribution of the 1-TG Au-NP change from 30 nm to 100 nm upon the addition of anions. The 1-TG Au-NP shows selective aggregation for F^- over other anions. The preference for F^- over other anions can be explained by the strong basicity of F^-. Less
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Research Products
(5 results)
