Sensitive molecular sensing using single molecule analysis of target-induced gold nanoparticle aggregation

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02527
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 27040:Biofunction and bioprocess engineering-related
• Research Institution: Ehime University
• Principal Investigator: Zako Tamotsu 愛媛大学, 理工学研究科(理学系), 教授 (50399440)
• Co-Investigator(Kenkyū-buntansha): 朝日 剛 愛媛大学, 理工学研究科(工学系), 教授 (20243165) ; 小川 敦司 愛媛大学, プロテオサイエンスセンター, 准教授 (30442940)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 金ナノ粒子 / 高感度検出 / 散乱光 / 暗視野観察 / 一分子計測

Outline of Final Research Achievements

Sensitivity and versatility are important for the detection of molecules such as biomarkers. Recently, gold nanoparticles (AuNPs) become more commonly adopted for molecular sensing applications because of their favorable optical properties; target-induced AuNPs aggregation can be recognized by a color change from red to blue. However, sensitivity was not enough for early recognition of diseases. In this study, we have found that the observation of AuNPs aggregation using scattered light can detect molecules with higher sensitivity. We also showed that by appropriately designing the surface of AuNPs, it is possible to detect a wide range of molecules, including small molecules, proteins, and nucleic acids. We also showed that AuNPs aggregation can be observed at the single molecule level by dark-field microscopy in real samples such as serums.

Free Research Field

バイオ分析化学

Academic Significance and Societal Importance of the Research Achievements

バイオマーカー等の分子検出には、これまでクロマトグラフィー法や抗体を用いた手法(ELISA)などが行われてきたが、早期疾病診断のためには、感度や汎用性が不足していた。本研究の成果により、金ナノ粒子凝集による分子検出の高機能化により、より簡便で高感度かつ汎用的な検出に繋がることが期待される。また、ナノ粒子の表面修飾により、血清や環境水などの実試料においても応用可能であることが示され、医療、環境化学分野での利用が期待される。