2016 Fiscal Year Annual Research Report
N-heterocyclic carbene-modified gold nanoparticles for biosensing
| Project/Area Number |
26288023
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| Research Institution | Nagoya University |
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Principal Investigator |
CRUDDEN Cathleen 名古屋大学, トランスフォーマティブ生命分子研究所, 客員教授 (10721029)
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| Project Period (FY) |
2014-04-01 – 2018-03-31
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| Keywords | Nano Material / Gold Nanoparticles / N-Heterocyclic Carbene / Bio-imaging / Stability / Photoacoustic Properties |
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| Outline of Annual Research Achievements |
This year we have made substantial progress in the area of NHC-stabilized nanoparticles. Our first publication appeared in Angewandte Chemie International Edition. This paper detailed our study of carboxylated NHCs as ligands for the preparation of water soluble gold nanoparticles. These nanoparticles were extensively studied and could be analyzed by polyacrylamide gel electrophoresis due to their charged nature. In basic pHs, the nanoparticles were exceptionally stable, however they aggregated under acidic pH. This aggregation was shown to be reversible. The NHC-stabilized nanoparticles were stable under a variety of biologically-relevant conditions, except thiol stability was still sub optimal. In addition to the synthetic and stability studies, in collaboration with the Yamaguchi group, we were able to test the photoacoustic properties of these nanoparticles. The nanoparticles were shown to have a linear response and even the smallest nanoparticles had a reasonable photoacoustic response.
In more recent work, we have prepared a new type of bidentate NHC, one that has a single NHC ligand and a thiol ligand on the same molecule. This compound was shown to make Au(1) nanoclusters when exposed to molecular gold, and to make highly stable nanoparticles when exposed to auric acid and reducing agents. In this work, we have prepared the first NHC-based nanoparticle that is stable to exogenous thiol. This work is very preliminary and will continue in the next funding year.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
The use of bidentate NHCs to stabilize nanoparticles has proven to be an excellent strategy and we believe will be the key to employing these nanoparticles in vivo. Synthetic issues in the previous year were overcome this year, permitting us to make two of the important structures that we needed to make, namely bidentate alkylated NHCs and bidentate NHC/thiol ligands. Both of these ligands turned out to be excellent supporting ligands for gold nanoparticles.
In addition to solving synthetic issues with regards to the preparation of the ligands, we were also able to analyze the water soluble nanoparticles with the assistance of the Itami and Higashiyama group at the Institute of Transformative Bio-Molecules.
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| Strategy for Future Research Activity |
Future work will focus on three areas:
(1) Completion of work on mixed thiol/NHC ligands and nanoparticles. The stability of these nanoparticles will be studied in more depth and the use of various linker lengths and nanoparticle sizes will be studied.
(2) The preparation of larger nanoparticles for a variety of applications will be a focus of this year. In collaboration with the Higashiyama group we will examine micron sized nanostructures for gene delivery and we will also examine more typical 40-50 nm structures for in vivo applications.
(3) Biological applications will also be addressed head on in this year since we now have a variety of sizes and types of water soluble nanoparticles and have the ability to prepare many types of NHC ligands. This will require bioconjugation studies.
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| Causes of Carryover |
新規金属ナノ粒子の合成を遂行する予定であった博士研究員の博士号取得が遅れたことにより雇用が遅れ、研究計画に大幅な遅延が生じたため
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| Expenditure Plan for Carryover Budget |
研究遂行の為の物品費、また研究発表のために使用する。
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Research Products
(20 results)
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[Journal Article] Simple direct formation of self-assembled N-heterocyclic carbene monolayers on gold and their application in biosensing2016
Author(s)
C. M. Crudden, J. H. Horton, M. R. Narouz, Z. Li, C. A. Smith, K. Munro, C. J. Baddeley, C. R. Larrea, B. Drevniok, B. Thanabalasingam, A. B. McLean, O. V. Zenkina, I. I. Ebralidze, Z. She, H.-B. Kraatz, N. J. Mosey, L. N. Saunders, A. Yagi
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Journal Title
Nature Communications
Volume: 7
Pages: 12654
DOI
Peer Reviewed / Open Access / Int'l Joint Research
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