Developments of Novel Terahertz Bio- sensing Technology with Thermal Curve Analysis
- 주제(키워드) Terahertz , Biosensors , classification , label-free sensing , epsilon-near-zero , Graphene oxide
- 주제(DDC) 621.042
- 발행기관 아주대학교 일반대학원
- 지도교수 Yeong Hwan Ahn
- 발행년도 2025
- 학위수여년월 2025. 2
- 학위명 박사
- 학과 및 전공 일반대학원 에너지시스템학과
- 실제URI http://www.dcollection.net/handler/ajou/000000034504
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Terahertz (THz) metamaterial-based biosensors have proven highly effective in detecting biomaterials. This thesis presents a novel classification method for microorganisms using THz metamaterials, while enhancing sensitivity and efficiency through various technical approaches to improve performance. In exploring the sensitivity applications of THz metamaterials, we characterized biosensors based on their high sensitivity to changes in dielectric constants. A variety of microorganisms were analyzed, observing their distinct characteristics. We focused on the molecular-level dielectric constant changes in microorganisms by measuring shifts in resonant frequency with applied heat. This enabled differential thermal curve (DTC) analysis, allowing us to identify key microbial thermal phases such as growth, thermal inactivation, DNA denaturation, and cell wall destruction. This analysis opens the possibility of providing unique microbial species-specific fingerprints without relying on fluorescent dyes or antibodies. One of the most remarkable discoveries was the ability to distinguish bacterial Gram types using the metamaterial biosensor, attributed to differences in cell wall thickness between Gram-negative and Gram-positive bacteria. This breakthrough not only aids in analyzing the thermal properties of microorganisms but also enables the differentiation of pathogenic bacteria, contributing to practical clinical systems and advanced diagnostic applications in environmental monitoring. Beyond biosensing applications, this research also introduces an innovative platform using graphene oxide (GO) to maximize the sensitivity of THz metamaterial-based biosensors. The epsilon-near-zero (ENZ) effect, observed when the dielectric constant of GO approaches zero at specific frequencies during reduction, matches the conditions required to amplify the metamaterial‘s sensitivity to environmental dielectric changes. This ENZ material presents a revolutionary method to further enhance biosensor sensitivity, paving the way for new biosensor development. In summary, this research maximizes the efficiency of metamaterial-based biosensors, broadening the scope of their potential applications through new diagnostic techniques and platforms.
more목차
Chapter 1 1
Introduction 1
1.1 Characteristic of metamaterials biosensors 1
1.2 Control the dielectric constant of Graphene oxide 2
1.3 Outline of the Thesis 3
Chapter 2 5
Background 5
2.1 THz time-domain spectroscopy 5
2.2 Metamaterials 8
2.3 Thermal Dynamics and Phase Behavior of Biomolecules 13
2.4 Graphene oxide film in THz frequency 16
2.5 Epsilon near zero materials (ENZ) 18
Chapter 3 22
The development of a terahertz (THz) label-free pathogen identification system 22
3.1 Introduction 22
3.2 Methods 24
3.3 THz thermal curve analysis 26
3.4 Summary 35
Chapter 4 36
THz Thermal Curve Analysis for Pathogen Identification and Gram-Type Differentiation 36
4.1 Introduction 36
4.2 Differential thermal curve results of bacterial species. 37
4.3 Thermal curve analysis for a mixture of bacteria 43
4.4 Summary 47
Chapter 5 48
The development of a THz epsilon-near-zero platform based on graphene oxide 48
5.1 Introduction 48
5.2 Methods 51
5.3 THz ENZ platform with Graphene oxide film 54
5.4 Summary 68
Chapter 6 69
The high-resolution imaging and sensing applications of the ENZ platform 69
6.1 Introduction 69
6.2 High-resolution imaging system with nondestructive testing 71
6.3 New sensing platform with the ENZ-meta hybrid sensors. 76
6.4 Summary 84
Chapter 7 85
Conclusions and Outlook 85
Appendix A 87
Bibliography 101
국문 요약 120
List of Publication 122
