Facile Synthesis of SERS-Active Metal (Au, Ag) Nanoflowers in The Presence of Chitosan

다국어 초록 (Multilingual Abstract)

Metal nanoflowers with many created “hot-spots” on the surface are the most attractive substrate in supporting for Surface-Enhanced Raman scattering (SERS) in the detection of biomolecules. This paper worked on the facile method for the fabrication of metal (Au, Ag) nanoflowers using ascorbic as reducing agent and chitosan as a capping agent. Gold annoflowers (AuNFs) with controllable size, morphology and Plasma absorbance were obtained by adjusting the experimental parameters such as chitosan concentration, pH of solution, and dosage amount of ascorbic acid. In case of silver nanoflowers (AgNFs), the morphology was easily controlled by either varying the volume of AgNO3 or chitosan concentration. These metal nanoflowers were further applied as an active SERS substrate in detecting 2-chlorothiophenol (CTP). The data showed the remarkable enhancement in SERS detection which proved the high efficiency in applying metal nanoflowers as active SERS substrate. The characteristics of as-prepared samples were analyzed by UV-Vis, SEM, TEM, SAED and XRD spectroscopy.

목차 (Table of Contents)

• CHAPTER 1. INTRODUCTION 7
• 1.1. Overview about SERS [1-5] 3
• 1.1.1. Historic and Fundamental 3
• 1.1.2 Key features of SERS 7
• 1.1.3 Hot-spot in SERS measurement 8
• 1.2. Overview about chitosan [6, 9, 13] 10
• 1.3. Overview about nanoflower fabrication 13
• CHAPTER 2. MATERIALS AND METHOD 15
• 2.1. Materials 15
• 2.2. Methods 15
• 2.2.1. Gold nanoflowers fabrication 15
• 2.2.2. Silver nanoflowers fabrication 16
• 2.3 Application in SERS 16
• CHAPTER 3. RESULTS AND DISCUSSION 17
• 3.1. Gold nanoflowers 17
• 3.1.2 The effect of ascorbic acid 17
• 3.1.2 The effect of chitosan concentration 20
• 3.1.3 The effect of pH of solution 23
• 3.1.4 The crystal structure of Gold nanoflowers 26
• 3.2. Silver nanoflowers 30
• 3.2.1 The effect of the dosage amount of silver nitrate 30
• 3.2.2 The effect of chitosan concentration 32
• 3.2.3 Mechanism for the formation of silver nanoflowers 34
• 3.3. Application in SERS 37
• CHAPTER 4. CONCLUSION 44
• Future Work 45
• References 46
• Acknowledgement 48