京都大学教育研究振興財団助成事業
成 果 報 告 書
令和 03 年 04 月 22 日
公益財団法人京都大学教育研究振興財団会 長

藤洋 作

助 成 の 種 類
申請時の科研費
研 究 課 題 名様

所属部局

京都大学 エネルギー理工学研究所

職名

講師

氏

名

アリワラガン ラジェンドラン

令和 02 年度 ・DNA origami-based chemiresistive sensors for chemical and biologicaldetections(DNAオリガミを利用して構築するケミレジスタセンサーの開発)

上記以外で助成金を 充 当 し た
研 究 内 容助成金充当に関わる共同研究者

研究活動推進助成なし（所属・職名・氏名）なし

発表学会文献等（この研究成果を発表した学会・文献等）
Delivered an Invited Lecture: A. Rajendran, Single molecular analysis of chemical and biologicalprocesses using DNA origami, International Conference on Recent Advancement in ChemicalSciences, Sona College of Technology, India, Online, 2020.8.10-14

成 果 の 概 要

研究内容・研究成果・今後の見通しなどについて、簡略に、A４版・和文で作成し、添付して下さい。 （タイトルは「成果の概要／報告者名」）
交付 を 受 けた 助成 金額

1,000,000円

使 用 し た 助 成 金 額

1,000,000円

返納すべき助成金額0円

費会計報

告助成金の使途内訳

目金額

Chemicals for Synthesis

374,962

Chemicals for Buffer

25,701

Reagents and Solvents

343,127

Enzymes

73,664

Purification Systems

132,374

Laboratory Consumables

40,733

Others

9,439（今回の助成に対する感想、今後の助成に望むこと等お書き下さい。助成事業の参考にさせていただきます。）当財団の助成についてI express my sincere gratitude for the research grant and supporting my research. The application process
for the Kyodai-Zaidan was very simple, and there was a high degree of freedom regarding the use ofsubsidies. I could accomplish considerable achievements using this grant, and one of my research article is
now in the revision stage and possibly it will be published soon. Most importantly, my application for
FY2021 Kiban-C got accepted. I sincerely hope that this foundation will greatly help many otherresearchers for the development of future research.

令和２年度京都大学教育研究振興財団
研究活動推進助成 「成果の概要」
令和 03年 04月 22日
成果報告者

京都大学エネルギー理工学研究所・講師 アリワラガン

ラジェンドラン「成果の概要」 DNA オリガミを利用して構築するケミレジスタセンサーの開発【研究内容】In recent years, extensive research has been focused on the development of sensors for the detectionof various analytes such as ions, gas molecules, common pollutants present in air and water, toxins
in food chains, disease-causing microorganisms, clinically important biomolecules, and so on. The
limitations of the current state-of-the-art sensors include the higher process time required for thedetection, poor sensitivity and selectivity of the sensor, and in-flexibility of the sensor platforms
for routine use. One notable example of these type of sensors is the chemiresistive sensor with theuse of conjugated organic molecules or conducting polymers. In this type of sensors, thedevelopment of sensing material that has good mechanical flexibility, tunable conductivity, highsensitivity and selectivity for the analyte is very challenging. Further, a single sensing
material/conducting polymer can’t be used for several analytes and it requires to develop analytespecific sensing material for each detection. Further, the applications of these sensors are quite
limited and seriously fail to distinguish analytes with similar properties/functionalities. For
example, the chemiresistive sensors fail to differentiate pathogens vs non-pathogens, and fail todistinguish different cell types. This is mainly because of the lack of specific functional receptors
in the conducting polymer which constitutes the sensing film. Thus, it is highly desirable to develop
a sensor platform that uses a single sensing molecule for various analytes while maintaining allother prerequisites of a sensor. Hence, in this research, I aimed to develop the chemiresistive
sensors that uses a single conducting polymer as a signal transducer while a DNA origami withfunctional receptor moieties as a sensing region. The same sensor system can be used for thedetection of diverse analytes just by changing the functional moieties that are deliberately placedon the origami.
【研究成果】

One major issue with the origami nano-biomaterials is their unsatisfactory stability that prevents
them from the applications in a wide range of conditions to withstand the thermal, mechanical andchemical modifications. Thus, the stability of DNA origami should be improved for the practicalapplications of sensor development. At first, we have carried out a detailed analysis for stabilizing
the origami structures. For this purpose, we have adapted the enzymatic and chemical ligations of
the discontinuities in the staple strands. The conditions for the ligation are now optimized. Our
results indicated that we could successfully stabilize the DNA origami structures with theoptimized conditions, and we could achieve the maximum ligation efficiency of about 75%.
Further, the ligation is found to increase the stability of the DNA origami over 20C, and also it isstable in the device fabrication conditions. Further, with the help of Prof. Praveen at IISc, India,
the candidate conducting polymers are developed, and their abilities to incorporate in thechemiresistive sensors are investigated.
【今後の見通し】

Next, the bioconjugation strategies to link the conducting polymers and DNA origami will bedeveloped. The incorporation of receptors on the DNA origami surface will then be studied. Oncethese functional materials are developed and combined to make the sensing films, they will beincorporated on the printed circuit board to produce the chemiresistive sensor. Then, finally thedeveloped sensor will be used for sensing the clinically important biomolecules, and diseasecausing microorganisms.