2012 Fiscal Year Final Research Report
Fabrication of Ag nanoplate-bio tip for evaluation of the binding between proteins and small molecules
| Project/Area Number |
23655074
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Analytical chemistry
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| Research Institution | Kansai University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
ARAKAWA Ryuichi 関西大学, 化学生命工学部, 教授 (00127177)
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| Project Period (FY) |
2011 – 2012
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| Keywords | バイオチップ / 銀ナノプレート / 低分子化合物 / タンパク質 / SALDI-MS / LSPR |
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| Research Abstract |
A complementary analytical methodology combining localised surface plasmon resonance (LSPR) sensing and matrix assisted laser desorption/ionisation-mass spectrometry (MALDI-MS) has been developed by using triangular silver nanoplates (Ag NPLs). Ag NPLs with near-IR LSPR absorbance were prepared via a two-step photo-mediated growth process from Ag nanoparticles. These could be utilised as a common platform for LSPR/MALDI-MS, as they were suitable for LSPR sensing via the analysis of surface plasmon adsorption bands and as the assisting material for LDI-MS. For practical use, the detection of analytes by LSPR sensing can be achieved by using specific biomolecular recognition techniques that involve the surface modification of metal NPs with large molecules such as proteins. We investigated the effect on LSPR sensitivity (i.e. refractive index unit, RIU) of modifying the Ag surface with molecules of different sizes, and found that the RIU values were proportional to the amplitude of the cube root of the molecular weight, Mw1/3. We demonstrated the utility of this complementary LSPR and MALDI-MS analysis methodology by evaluating the binding of soy bean trypsin inhibitor to the Ag NPL substrate covalently modified with trypsin. This specific biomolecule recognition phenomenon was first detected using the LSPR technique, and then successfully identified by the MALDI-MS.
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