Development of highly sensitive pathogenic microbial sensors with nano-sized reaction fields

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18737
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 22:Civil engineering and related fields
• Research Institution: Hokkaido University
• Principal Investigator: Satoh Hisashi 北海道大学, 工学研究院, 教授 (80326636)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: センサ / 病原体 / 水系感染症 / 核酸 / 簡易分析

Outline of Final Research Achievements

RNA is a crucial diagnostic biomarker for several human diseases. Hence, a simple, rapid, sensitive, and cost-effective assay for detecting pathogen-derived RNAs (e.g., RNA viruses) in water is necessary for transcriptomic analysis. Here, we present a highly sensitive assay to detect unamplified RNA based on the light scattering properties of oligonucleotide-functionalized gold nanoparticle probes (Au-nanoprobes). In this assay, Au-nanoprobes recognize and hybridize to the target RNA. Subsequently, they scatter light when the sample solution is placed onto a quartz waveguide slide and is excited with an evanescent wave. This assay enables highly sensitive quantification (approximately 102 copies/μL) of bacterial 16S rRNA and mRNA without reverse transcription and cDNA amplification within 10 min of RNA extraction. Moreover, this assay was three orders of magnitude sensitive than previously reported assays for direct RNA quantification.

Free Research Field

水環境工学

Academic Significance and Societal Importance of the Research Achievements

現在、世界全体では約20億人が安全な飲料水を利用できていない。2016年には安全でない飲料水供給施設や衛生設備の不足が原因で世界で87万人の関連死が発生した。そのため、高感度病原性微生物センサーの開発が望まれている。本法が完成すればPCR法によらずに、遺伝子抽出後は簡易に（DNAプローブとサンプルを混合するのみ）、迅速に（10分）、低コストで（1サンプル1円）病原体を検出できる。熟練の技術者がいない過疎地域や開発途上国でも飲料水中や公共用水域の病原体濃度を測定できるようになる。水の汚染発覚後、自治体は迅速に問題に対応できる。