복합 식품 매트릭스 내 병원균의 신속 검출을 위한 통합 필터 기반 시료 전처리 및 비색 바이오센서 시스템 개발

다국어 초록 (Multilingual Abstract)

Rapid and accurate detection of foodborne pathogens in food is crucial for food safety and public health. However, conventional detection methods such as culture-based assays and PCR-based techniques are limited by long detection times, the need for sophisticated equipment, and interference from complex food components, which restrict their on-site applicability. To address these challenges, field-applicable biosensor technologies that integrate efficient pretreatment with rapid diagnosis are required. In this study, an integrated system for the rapid and accurate detection of foodborne pathogens in food matrices was developed using filter-assisted sample preparation (FASP). The FASP method effectively separated pathogens from real food samples, thereby enhancing sensitivity and reproducibility. With the immunoassay-based colorimetric biosensor, real samples such as tomatoes yielded colorimetric signals comparable to those in PBS buffer, thereby demonstrating the accuracy and stability of the combined FASP and biosensor system. Based on these results, an integrated platform was developed that applies pretreatment and colorimetric biosensing to various food matrices, including vegetables, meat, and cheese brine. The system allowed sensitive detection of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes down to 10^1 CFU/mL in various pretreated sample solutions. Simple pretreatment was completed within 3 minutes and detection within 2 hours, allowing results to be confirmed without need for specialized equipment. This study demonstrates the progression from proof-of-concept to the development of an integrated system and highlights that the combination of efficient pretreatment and biosensor technology can serve as a rapid, field-applicable pathogen detection platform for food safety applications.

목차 (Table of Contents)

• Ⅰ. Introduction 01
• Ⅱ. Materials and methods 05
• 2.1 Filter-assisted sample preparation (FASP) 05
• 2.1.1 Overall experimental workflow 05
• 2.1.2 Filter optimization for FASP efficiency 07
• 2.1.3 Quantitative and morphological analysis of bacteria throughout the FASP process 08
• 2.1.4 Real food samples 10
• 2.1.5 Optimized filtration process 11
• 2.1.6 Recovery of bacteria from various food matrices 14
• 2.2 Immunoassay-based colorimetric biosensor 15
• 2.2.1 Biosensor materials 15
• 2.2.2 Synthesis of streptavidin-functionalized gold nanoparticles 15
• 2.2.3 Bi-functional linker-based colorimetric biosensor 16
• 2.2.4 Comparative evaluation of FASP and conventional sample preparation methods in real food matrices 18
• 2.2.5 Application of an integrated rapid diagnostic system across diverse food matrices 19
• 2.2.6 Assessment of biosensor selectivity 20
• 2.3 Bacterial strains and culture conditions 20
• 2.4 Statistical analysis 20
• Ⅲ. Results and discussion 21
• 3.1 Optimization of FASP 21
• 3.1.1 Filter material and pore size 21
• 3.1.2 Overall changes of bacteria throughout the FASP process 24
• 3.1.3 Selection of various food matrices 27
• 3.1.4 Recovery of bacteria from various food matrices 29
• 3.1.5 Importance of FASP in real matrices 35
• 3.1.6 Comparison of negative controls in real matrices 38
• 3.2 Colorimetric biosensor integrated with FASP 40
• 3.2.1 An integrated rapid diagnostic system combining FASP and colorimetric biosensing 40
• 3.2.2 Validation of the biosensor 42
• 3.2.3 Detection of foodborne pathogens in complex food matrices 43
• 3.2.4 Quantitative detection 47
• 3.2.5 Selectivity of the biosensor 49
• 3.2.6 On-site detection 51
• Ⅳ. Conclusion 53
• References 57
• Korean Abstract 69