Creation of Silicon Nanowire Biosensor with Attomolar(aM) Sensitivity for Early Diagnosis of Infectious Disease

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K23598
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0403:Biomedical engineering and related fields
• Research Institution: Gunma University
• Principal Investigator: Zhang Hui 群馬大学, 大学院理工学府, 助教 (80794586)
• Project Period (FY): 2019-08-30 – 2022-03-31
• Keywords: シリコンナノワイヤ / バイオセンサ / 細線化 / 電子線描画 / 高感度 / 医用システム

Outline of Final Research Achievements

To detect biomolecules with high sensitivity in the early stage of virus infection, we investigated the sensitivity dependence of width and impurity concentration of Si nanowires (NW) in both theoretical analysis and experiments. By controlling the conditions of electron beam lithography and reactive ion etching, ultra-thin SiNW with a width of 11 nm was fabricated and succeeded in detecting immunoglobulin G(IgG) with a concentration of 6 aM by antigen-antibody specific binding. From the results of IgG detection using SiNWs of different widths, it was demonstrated that the detection sensitivity was significantly improved associated with the thinning of NW. In addition, it was confirmed that the detection sensitivity was increased by reducing the impurity concentration of SiNW.

Free Research Field

ナノ電子デバイス、医用システム関連

Academic Significance and Societal Importance of the Research Achievements

ウイルス感染症の広がりにより、感染初期段階での極微量な生体分子を高感度かつ迅速に検出できる診断法の開発が渇望されている。PCR法は低濃度物質の高精度検出が可能だが、測定に時間と労力がかかってしまう。本研究では、理論解析にて高感度化につながる要素を分析し、ナノ微細加工技術で細線化と不純物濃度を低減したSiNWバイオセンサを作製することで濃度6 aMの免疫グロブリンG（IgG）の特異的検出に成功した。極微量な生体分子の検出が可能となったこの研究成果により、将来、画期的な疾病の早期診断技術を社会に提供できると考えている。