2019 Fiscal Year Annual Research Report
Nanojet enhanced fiber sensor with dielectrophoretic concentration for rapid bacteria identification
| Project/Area Number |
18F18351
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| Research Institution | The University of Tokyo |
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Principal Investigator |
J・J Delaunay 東京大学, 大学院工学系研究科(工学部), 准教授 (80376516)
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| Co-Investigator(Kenkyū-buntansha) |
TAI YI-HSIN 東京大学, 工学(系)研究科(研究院), 外国人特別研究員
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| Project Period (FY) |
2018-11-09 – 2021-03-31
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| Keywords | particle trapping / Raman spectroscopy |
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| Outline of Annual Research Achievements |
Two optical fiber tips, facing each other, are used to trap and detect particles as well as bacteria suspended in a fluidic channel. This fiscal year, the main achievements are threefold: 1) optimization of the shapes of the two fiber tips to achieve enhanced surface Raman spectroscopy near the tip of one of the two fibers, 2) identification of Raman signal that can be used for bacteria discrimination, and 3) particle trapping between the two optical fiber tips by dielectrophoresis that is made possible by the coating of the two fiber tips with transparent and conductive ultra-thin films.
The proposed tip fibers have also been used to develop an ultra-sensitive portable refractometer (collaboration with Professor Pei-Kuen Wei, Academia Sinica, Taiwan) with the ability to monitor variation in solutes such as sucrose (published in the journal sensors).
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| Current Status of Research Progress |
Current Status of Research Progress
3: Progress in research has been slightly delayed.
Reason
Using the fabricated optical fiber tips, Surface enhanced Raman spectroscopy and particle trapping have been demonstrated separately. The combination of the two techniques on the same pair of optical fiber tips is difficult. Currently, the Raman signal is too weak to be collected by an optical fiber tip coated with the thin conductive layer that is used for the dielectrophoresis process. Further optimization of the different fabrication processes is required to improve the intensity of the Raman signal and its collection by the fiber tip.
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| Strategy for Future Research Activity |
Combine the two techniques for excitation/collection of surface-enhanced Raman signal and trapping particles on the same pair of optical fiber tips. Achieve simultaneously particle trapping and their detection/identification by Raman spectroscopy. Specifically, we will attempt detection of the Raman signal of adenine which is thought to be produced by bacteria (ATTC 25922). To demonstrate the validity of the technique, variation in the Raman signal intensity will be recorded as a function of the relative position of the two optical fiber tips and bacteria concentration.
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