Sensor effect using graphene composite combined with metal sulfide = 금수 황화물과 결합한 그래핀 복합재를 이용한 센서 효과

다국어 초록 (Multilingual Abstract)

The misuse of antibiotics and the presence of their residues have emerged as significant global environmental and health concerns. Therefore, it is of great importance to develop rapid and sensitive detection techniques. This study aims to address the limitations of conventional methods, such as cumbersome procedures and long detection times, by constructing a series of graphene (G)–metal sulfide (MnS, NiS, MoS₂)–silica (SiO₂) ternary nanocomposites. These composites serve as the basis for high-performance enzyme-free electrochemical sensors capable of highly selective and sensitive detection of trace antibiotics in aquatic environments. In this work, ternary nanocomposites—MnS–G–SiO₂, NiS–G–SiO₂, and MoS₂– G–SiO₂—were successfully synthesized via hydrothermal and chemical synthesis routes. The crystal structure, microstructure, and elemental composition of the as- prepared materials were thoroughly characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The composite materials were formulated into pastes and coated onto nickel foam electrodes. Electrochemical performance was systematically evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) for the detection of antibiotics such as amoxicillin, tetracycline, and doxycycline. Material characterization confirmed the uniform dispersion of metal sulfide nanoparticles on graphene sheets. The incorporation of SiO₂ effectively inhibited material aggregation and promoted the formation of a porous conductive network, providing a large specific surface area and abundant active sites. Electrochemical tests revealed outstanding sensor performance: The MnS–G–SiO₂ sensor for amoxicillin exhibited a good linear response in the range of 0.05–0.30 μM, with a detection limit (LOD) of 0.85 μM. The NiS–G–SiO₂ sensor for tetracycline showed an extended linear range of 0.05–0.40 μM and an LOD as low as 0.0761 μM. The MoS₂–G–SiO₂ sensor for doxycycline demonstrated the highest sensitivity, achieving an impressive LOD of 0.85 nM. These sensors also displayed excellent selectivity, repeatability, and stability, with only about 4.8% signal attenuation after 25 days of storage. When applied to real-world samples such as milk, their performance was comparable to that in PBS buffer, indicating strong potential for practical application. The remarkable sensing performance can be attributed to the synergistic effects among the high conductivity of graphene, the catalytic activity of metal sulfides, and the structural stability provided by silica. Keywords: Graphene composites, Metal sulfides, Electrochemical sensor, Antibiotic detection

목차 (Table of Contents)

• CONTENTS OF TABLES I
• CONTENTS OF FIGURES II
• ABSTRACT IV
• SENSOR EFFECT USING GRAPHENE COMPOSITE COMBINED WITH METAL SULFIDE 1
• 1.INTRODUCTION 1
• 1.1．REASON FOR THE RESEARCH 1
• 1.2．CLASSIFICATION OF ANTIBIOTICS 2
• 1.3．ENVIRONMENTAL IMPACTS OF ANTIBIOTICS 4
• 1.3.1 Core Pathways for Antibiotics Entering the Environment 4
• 1.3.2 Specific Hazards of Antibiotics to the Environment 5
• 1.3.2.1 Polluting Water Bodies: Damaging Aquatic Ecosystems, Threatening Drinking Water Safety 5
• 1.3.2.2 Polluting Soil: Reducing Soil Fertility, Damaging Soil Ecology 6
• 1.3.2.3 Threatening Biodiversity: Disrupting Ecological Balance 7
• 1.3.2.4 Indirect Feedback on Human Health Risks: Forming an "Environment-Human" Resistance Cycle 8
• 1.4. CLASSIFICATION OF SENSOR MATERIALS 9
• 1.4.1 Physical Quantity Sensor Materials 9
• 1.4.2 Chemical Quantity Sensor Materials 11
• 1.4.3 Biological Quantity Sensor Materials 13
• 1.5.THE SENSOR EFFECT OF GRAPHENE MATERIALS 15
• 1.6.SENSOR EFFECTS OF METAL SULFIDES 18
• 1.6.1 Gas Sensing Effect: Based on Surface Adsorption - Electron Transport Modulation 18
• 1.6.2 Photoelectric Sensing Effect: Based on Generation and Separation of Photoinduced Electron-Hole Pairs 19
• 1.6.3 Temperature Sensing Effect: Based on Resistance-Temperature Dependence 20
• 1.6.4 Pressure/Strain Sensing Effect: Based on Coupling Mechanical Deformation and Electronic Properties 21
• 1.7.RESEARCH OBJECTIVES AND SIGNIFICANCE OF THIS PROJECT 22
• 2. EXPERIMENTAL MATERIALS AND METHODS 25
• 2.1. MATERIALS 25
• 2.2.SYNTHESIS 25
• 2.3. FABRICATION OF ELECTRODE 29
• 2.4. CHARACTERIZATION 30
• 3. RESULTS AND DISCUSSION 33
• 3.1.MATERIAL STRUCTURE AND MORPHOLOGY CHARACTERIZATION 33
• 3.1.1 Crystal Structure Analysis 33
• 3.1.2 Microstructural Morphology Characteristics 38
• 3.1.3 Surface Chemical State Analysis 42
• 3.2. ELECTROCHEMICAL PERFORMANCE 48
• 3.3. ANTIBIOTIC SENSING WITH THE ELECTRODE 54
• 4.CONCLUSIONS 69
• 4.1. THE CONCLUSION OF THE EXPERIMENT 69
• 4.2.RESEARCH OUTLOOK 71
• 4.2.1 Material System Optimization and Innovation 71
• 4.2.2 Research on the perception mechanism 71
• 4.2.3 Multifunctional Integration and Intelligent Development 71
• 4.2.4 Practical Application Expansion and Validation 72
• 4.2.5 Industrialization Technology Development 72
• REFERENCES 73
• 국문초록 88