A Portable Pathogen Detection System by Integrating Non- Spectroscopic Optical Immunosensing and Miniaturized Sample Processing
- 주제(키워드) Pathogen bacteria , Point-of-care testing , Microfluidic chip , Retroreflective Janus particle , Miniaturized sample processing , Optical sensing
- 주제(DDC) 547
- 발행기관 아주대학교 일반대학원
- 지도교수 윤현철
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000035608
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Foodborne pathogens such as Enterohemorrhagic Escherichia coli (EHEC) present significant public health risks and growing safety challenges in the food industry, necessitating rapid and quantitative detection methods. Despite the rapidity of traditional agglutination assays, they lack quantification capability, whereas gold-standard methods such as ELISA and PCR offer high sensitivity but require complex equipment and lengthy procedures that limit field use. In this study, we developed a field-deployable diagnostic system using a distance-based microfluidic chip for pathogen detection. This system comprises a compact Peltier-based bacterial enrichment device and an Arduino-controlled aggregation reactor, which are both powered by a portable battery. The enrichment device increases bacterial concentration, while the reactor promotes aggregation with particles. Detection is performed using a distance-based microfluidic chip fabricated by bonding plasma-treated PDMS to a glass substrate to enable passive fluid flow without external pumps for enhancing portability for field use. Signal acquisition is performed using retroreflective Janus particles (RJPs) as the optical probes. This enables quantitative bacterial analysis using only a smartphone LED flash and CMOS camera. As bacterial concentration increases, aggregation with RJPs reduces the signal distance, allowing rapid and efficient detection without the need for complex optical equipment. This platform integrates bacterial enrichment, aggregation, and detection into a compact, portable system. It demonstrates superior performance in terms of field applicability, sensitivity, and quantification, offering significant improvements over existing technologies.
more목차
1. Introduction 1
1.1 Importance of early detection of Enterohemorrhagic E. coli (EHEC) 1
1.2 Conventional methods for detection of EHEC 3
1.3 Sensing strategy of a portable EHEC detection system 5
1.4 Miniaturized sample processing strategy for on-site detection 10
1.5 Aim of the Thesis 13
2. Materials and methods 14
2.1 Reagents and apparatus 14
2.2 Fabrication of RJPs as optical probes 16
2.3 Fabrication of a distance-based microfluidic chip for sensing 17
2.4 Preparation of EHEC samples 19
2.5 Fabrication of reactor adapter for microcontroller-based reactor 21
2.6 Algorithm for image-based data digitization 23
3. Results and discussion 25
3.1 Development of a portable enrichment system 25
3.1.1 Development of a miniaturized enrichment device 25
3.1.2 Optimization of EHEC enrichment temperature 28
3.2 Development of a microcontroller-based reactor 30
3.3 Verification of optical signaling probe 32
3.4 Feasibility test of a microcontroller-based reactor with distance-based microfluidic chip 35
3.5 Optimization of agglutination time with microcontroller-based reactor 38
3.6 Quantitative analysis of EHEC detection using a non-spectroscopic optical system 40
3.7 Quantitative analysis of EHEC detection using a smartphone 42
4. Conclusions 45
5. References 46
