2022 Fiscal Year Research-status Report
Extended Pyrazinacenes as a New Class of Near-Infrared Emissive Materials for Potential Bioimaging Applications
| Project/Area Number |
21K05044
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| Research Institution | Shibaura Institute of Technology |
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Principal Investigator |
RICHARDS GARY 芝浦工業大学, 工学部, 准教授 (00708620)
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| Co-Investigator(Kenkyū-buntansha) |
堀 顕子 芝浦工業大学, 工学部, 教授 (90433713)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | Pyrazinacenes / Azaacenes / Near Infrared Emitters / Fluorescence / REDOX / Near infrared absorption |
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| Outline of Annual Research Achievements |
We have continued to synthesize new pyrazinacenes mainly consisting of four or five consecutively fused pyrazine rings appended with electron-donating substituents that are redox active. Oxidized species show remarkably red-shifted absorption compared to the reduced species.
We have improved the synthesis of the water-soluble tetradecaazaheptacene to give better yield. This compound has been used for cellular imaging in the near infrared region. This was possible through use of a non-cytotoxic beta-cyclodextrin delivery agent which helped to prevent chromophore aggregation in aqueous solution.
We have now developed the synthesis of pyrazinacenes consisting of 8 consecutively fused pyrazine rings - now the longest-known pyrazinacenes.
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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
We have already managed to prepare water-soluble extended pyrazinacene emitters that exhibit highly efficient fluorescence in the near-infrared region (peak emission = 730 nm). Although aggregation of this chromophore quenches fluorescence in aqueous solution, we have found a suitable delivery agent that prevents aggregation and allows the dye molecules to be used as emitters for cellular imaging in the near infrared region. We are now in the process of submitting a patent application related to this work.
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| Strategy for Future Research Activity |
Working with our collaborators at NIMS, we will continue to develop our work on cellular imaging applications of our water-soluble tetradecaazaheptacene - in particular, we hope to use this material for continuous live cell imaging in the near infrared region
We will continue our efforts to synthesize new materials including those consisting of 8 fused pyrazine rings (for example, water-soluble derivatives), and shorter, redox-active compounds appended with various electron donor substituents.
We will continue to investigate these compounds for application as new types of emitters for bio and cellular imaging applications as well as for application in other nascent technologies.
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| Causes of Carryover |
International conferences were deferred due to COVID 19 pandemic. Research associated with this funding will be presented internationally in 2023.
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