2022 Fiscal Year Research-status Report
Novel label-free tool for infections diagnosis based on Nano-Electro Optical Tweezers
| Project/Area Number |
20K12701
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
KOTSIFAKI Domna 沖縄科学技術大学院大学, 量子技術のための光・物質相互作用ユニット, 客員研究員 (70834117)
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| Project Period (FY) |
2020-04-01 – 2024-03-31
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| Keywords | Raman Spectroscopy / Nano-apertures / Metallic devices / Bacteria |
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| Outline of Annual Research Achievements |
I studied theoretically the enhancement of the electromagnetic field of the device using Comsol Multiphysics software in my third year of the project. I have designed and fabricated the size of the nano-aperture comparable to the volume of a single-bacterium so that the microorganism flowing close to the region with a strong field will be trapped, permitting studies at the single-cell level. When the trap was full, there is not energy confined around the trapped bacterium, so preventing, or at least remarkably reducing the probability, that another bacterium will be trapped in the same region. Moreover, by introducing an array of nanohole, many trapping sites have be activated at the same time; hence the proposed approach enabled the simultaneous analysis of several bacteria locally in well-defined positions. By arraying the nanohole, multiple signatures in parallel will be obtained, permitting a measurable signal in case of very weak interaction.
I found the theoretical resonance modes of the proposed device. Using antibiotics added to the surrounding medium, I have examined the growth, survival, and reproduction mechanisms of the trapped bacteria using Raman spectroscopy. Unfortunately, the results are not good. As a result, I analyzed the SERS signal during the growth stages of the bacteria. In my study, I found that the intensity of the amide protein characteristics peaks increases during exponential phases and decreases during stationary phases. The results are in agreement with the theoretical explanations.
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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
So far, the project has progressed smoothly. However, some modifications were made to meet the project's requirements. In the first step, I have modified the geometric characteristics of the proposed device after extensive theoretical and experimental research. Gram-negative bacteria were used to evaluate the platform.
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| Strategy for Future Research Activity |
The next step will be to publish the experimental results and write the final report.
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| Causes of Carryover |
Delivery of equipment was delayed due to unforeseen circumstances
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Research Products
(3 results)
