【公開日：2024.07.25】【最終更新日：2024.05.29】
課題データ / Project Data
課題番号 / Project Issue Number
23UT0089
利用課題名 / Title
Sub-10 nm Nanopore STEM drilling for ssDNA sequencing
利用した実施機関 / Support Institute
東京大学 / Tokyo Univ.
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）次世代ナノスケールマテリアル/Next-generation nanoscale materials（副 / Sub）次世代バイオマテリアル/Next-generation biomaterials
キーワード / Keywords
Nanopore, Molybdenum disulfide,電子顕微鏡/ Electronic microscope,バイオセンサ/ Biosensor,原子層薄膜/ Atomic layer thin film,ナノ多孔体/ Nanoporuous material
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Lee Chun-Yen
所属名 / Affiliation
東京大学 大学院工学系研究科
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
Takayuki Moriga
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
Mari Morita
利用形態 / Support Type
（主 / Main）技術補助/Technical Assistance（副 / Sub）,機器利用/Equipment Utilization
利用した主な設備 / Equipment Used in This Project
UT-002：軽元素対応型超高分解能走査透過型電子顕微鏡（Cs-STEM）
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
Our study focuses on the fabrication of sub-10-nm nanopores, ranging from 0.7 nm to 7 nm, within monolayer MoS2. This was achieved through a combination of Ronchigram adjustment and ultra-fine electron beams, conducted under scanning electron transmission microscopy (STEM), for both exfoliated MoS2 and Chemical Vapor Deposition (CVD) MoS2.The utilization of these techniques provided precise control over nanopore shape, resulting in well-defined circular structures. The circular nanopore shape is particularly advantageous for ssDNA sensing experiments and peptide sequencing under sub-1 nm MoS2 nanopores. This shape enhances time resolution effects and enables higher precision in DNA molecule detection.Additionally, the circular shape of the nanopores facilitates the study of surface charge properties between single crystal and defective structures. A notable advantage of this technique is the production of circular nanopores without compromising the crystallinity of the MoS2 material. This finding suggests that high-quality nanopores can be produced while preserving the material properties necessary for optimal sensing performance.The outcomes of our study hold significant implications for the design and optimization of nanopore-based DNA and peptide sensing technologies. By enabling the production of circular nanopores with high crystallinity, this technique has the potential to substantially enhance the performance of future nanopore sensors.
実験 / Experimental
To achieve the fabrication of sub-10 nm nanopores, we utilize the highly focused electron beam generated by scanning transmission electron microscopy (STEM). Our approach involves meticulous steps to enhance beam focus and minimize aberrations, particularly astigmatism.To improve beam focus and mitigate astigmatism, we commence by precisely adjusting the Ronchigram within the silicon nitride (SiN) area. Subsequently, we apply a monolayer of molybdenum disulfide (MoS2) to cover the SiN substrate. This process aids in refining the beam's focal properties.Following the Ronchigram adjustment, we proceed to drill the nanopore within the standalone MoS2 region. This sequential approach ensures optimal beam quality and facilitates the precise fabrication of sub-10 nm nanopores.Astigmatism, a common optical aberration, arises when the magnetic lens deviates from perfect circularity, resulting in dual focal points. Our methodology aims to mitigate this effect, thereby enhancing the accuracy and resolution of nanopore fabrication.
結果と考察 / Results and Discussion
In this study, we successfully fabricated sub-10-nm nanopores within monolayer MoS2, ranging from 0.7 nm to 7 nm, employing a combination of Ronchigram adjustment and ultra-fine electron beams under scanning electron transmission microscopy (STEM). Our approach was applied to both exfoliated MoS2 and Chemical Vapor Deposition (CVD) MoS2 substrates.The techniques utilized in our fabrication process allowed for precise control over nanopore shape, resulting in well-defined circular structures. The circular morphology of the nanopores offers distinct advantages for ssDNA sensing experiments and peptide sequencing under sub-1 nm MoS2 nanopores. Specifically, the circular shape enhances time resolution effects and enables higher precision in DNA molecule detection.Moreover, the circular configuration of the nanopores facilitates the investigation of surface charge properties between single crystal and defective structures. A significant benefit of our technique is the production of circular nanopores without compromising the crystallinity of the MoS2 material. This observation indicates that high-quality nanopores can be generated while maintaining the material properties essential for optimal sensing performance.The implications of our findings are substantial for the advancement and optimization of nanopore-based DNA and peptide sensing technologies. By enabling the fabrication of circular nanopores with high crystallinity, our technique holds promise for enhancing the performance of future nanopore sensors.In summary, our study demonstrates a novel approach for the fabrication of precise nanopores within MoS2 monolayers, offering insights into their potential applications in DNA and peptide sensing. The controlled production of circular nanopores represents a significant step forward in the development of nanopore-based sensing platforms, paving the way for enhanced sensitivity and accuracy in molecular detection.
図・表・数式 / Figures, Tables and Equations
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
We express our gratitude to Morita-san and Professor Egusa from the Materials Science department at the University of Tokyo for their invaluable technical support and guidance in our research endeavors.
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件