7 research outputs found
μΉ΄μ΄λ λλ Έκ΅¬μ‘°μ νλΌμ¦λͺ¬ 컀νλ§μ κΈ°λ°ν μνΈκ΄ μ΄μμ± λ³μ‘°
νμλ
Όλ¬Έ(λ°μ¬) -- μμΈλνκ΅λνμ : 곡과λν μ¬λ£κ³΅νλΆ, 2022.2. λ¨κΈ°ν.μΉ΄μ΄λ λ©ν λ¬Όμ§μ λ°μ΄λ κ΄ λ¬Όμ§ μνΈ μμ©μΌλ‘ μΈνμ¬ λλ
Έ κ΄μ λΆμΌμμ ν° κ΄μ¬μ λ°μμλ€. λ€λ
κ°μ μ°κ΅¬λ₯Ό ν΅νμ¬ μ΅μ²¨λ¨ 리μκ·ΈλνΌ κΈ°μ κ³Ό λΆμ 쑰립 μ€μΊν΄λλ₯Ό μ¬μ©νμ¬ μΉ΄μ΄λ λλ
Έκ΅¬μ‘°κ° μ μλμ΄ μλ€. κΈ°ννμ λΉλμΉμ±μ μ§λλ μΉ΄μ΄λ 무기 κΈμ λλ
Έ λ¬Όμ§μ λμΉμ±μ κ°μ§λ λλ
Έ λ¬Όμ§μμ μ»μ μ μμλ λ
νΉν 물리μ νμμ λνλΌ μ μλ€. μΉ΄μ΄λ λλ
Έ ꡬ쑰λ μμ κ΅΄μ λ₯ , λΆμ κ°μ§ λ° κ΄λμ μν νΈκ΄κ³Ό κ°μ κ΄νμ ν¨κ³Όλ₯Ό λνλ΄κΈ° μν΄ μ¬μ©λ μ μλ€. μ΄λ¬ν μΉ΄μ΄λ λ©ν λ¬Όμ§μ λ°μ΄λ κ΄ν νΉμ±μ μ€μ μ₯μΉμ ν΅ν©νκΈ° μν΄μλ μ¬μΈνκ² μ€κ³λ κ΄νμ μ±μ§μ κ°μ§λ μΉ΄μ΄λ ꡬ쑰λ₯Ό λ¬μ±νλ κ²μ΄ νμνλ€. κ·Έλ¬λ κ³ κ°μ μ μ‘°λΉμ© λ° μ€λΉ, 볡μ‘ν μ μ‘° κ³Όμ λ° μ νλ ν΄μλλ‘ μΈν΄ μΉ΄μ΄λ λ©ν λ¬Όμ§μ μ€μ μ₯μΉλ‘ ν΅ν©νλ λ° μ νμ΄ μμ΄μλ€. μ΄λ¬ν νκ³λ₯Ό 극볡νκΈ° μν΄μλ μΉ΄μ΄λ λλ
Έ ꡬ쑰 μ μ΄λ₯Ό μν μ μ°ν λ°©λ²λ‘ μ κ°λ°νλ κ²μ΄ μꡬλλ€. λ³Έ νμ μ°κ΅¬ μμλ ν©νμ΄λλ₯Ό μ΄μ©ν λλ
Έ μ
μ ννμ λ€μνμ λλ
Έ ꡬ쑰μμμ νλΌμ¦λͺ¬ 컀νλ§μ μ΄μ©ν κ΄νμ λ°μμ μΆκ°μ μΈ μ‘°μ μ΄ μμ μΈκΈν νκ³λ₯Ό ν΄κ²°νκΈ° μν μ λ§ν λμμ΄ λ μ μμμ μ μνλ€. λ³Έ νμ λ
Όλ¬Έμ μΉ΄μ΄λ λλ
Έ ꡬ쑰μ λ°λ¬μ λν μ΄ν΄μ μ‘°μ μ ν΅ν΄ νλΌμ¦λͺ¬ 컀νλ§μ μ΄μ©νμ¬ μΉ΄μ΄λ κ΄ν μλ΅μ μ‘°μ ν μ μλ νλ«νΌμ μ μνλ€.
μ체λΆμλ₯Ό μ΄μ©ν νλΌμ¦λͺ¬ λλ
Έ μ
μμ μ½λ‘μ΄λ ν©μ±μ λν μ΅κ·Ό μ°κ΅¬κ²°κ³Όλ ν©μ± κ³Όμ μ κ΄μ¬νλ μΉ΄μ΄λμ± μΈμ½λμΈ λΆμλ₯Ό λ³κ²½ν¨μΌλ‘μ¨ μλ‘μ΄ ννμ κ΄νμ νΉμ±μ κ°μ§ λλ
Έμ
μλ₯Ό ν©μ±ν μ μμμ μμ¬νλ€. λν λ¨μΌ νλΌμ¦λͺ¬ μ
μμ κ΄ν μλ΅μ νλΌμ¦λͺ¬ 컀νλ§μ μ¬μ©νμ¬ μ¦νλκ³ λ―Όκ°νκ² λ³μ‘°λ μ μλ€. μ¬λ¬ νλΌμ¦λͺ¬ λλ
Έ μ
μκ° μΈμ ν κ²½μ°, μ
μ 곡λͺ
μ νΌμ±νκ° μ λλμ΄ κ³΅λͺ
μ ν¬κ² λ³νμν¨λ€. νλΌμ¦λͺ¬ λλ
Έ ꡬ쑰μ ννμ μΉ΄μ΄λμ±μ μ μ΄νκΈ° μν μλ‘μ΄ μ λ΅μ μ립νκΈ° μνμ¬, μ°λ¦¬λ λ¨Όμ μ체λΆμμ μν΄ μ λλλ 무기 μΉ΄μ΄λμ±μ μ΄μ μ λ§μΆμλ€. 무기 νλ©΄μμμ μμ μ곑 λλ κ±°μμ μ¬κ΅¬μ±μ ν΅ν μΉ΄μ΄λμ±μ μ§νμ λν κΈ°μ‘΄ μ°κ΅¬λ μΉ΄μ΄λ λλ
Έ ꡬ쑰 μ μ΄λ₯Ό μν μλ‘μ΄ μ λ΅ μ립μ μ€μν ν΅μ°°λ ₯μ μ 곡νλ€. λ³Έ νμλ
Όλ¬Έμμλ μΉ΄μ΄λ κ΄ν λ°μμ μ΄ν΄μ μ‘°μ μ λ¨μΌ λλ
Έ μ
μμ μμ€ν
μ μ μ΄μ λ κ°μ§ κ΄μ μμ μκ°νλ€.
λλ
Έ μ¬λ£ 곡νμ λ°μ μΌλ‘ λλ
Έ κ·λͺ¨μμ μ νν νννμ μ μ΄κ° κ°λ₯ν μ½λ‘μ΄λ ν©μ± λ°©λ²μ΄ κ°λ°λμλ€. λ€μν ν λ‘κ²νλ¬Ό μ΄μ¨, κΈμ μ΄μ¨ λ° μ κΈ° λΆμλ₯Ό ν‘μ°©μ λ‘ μ¬μ©νλ©΄ νΉμ Miller μ§μλ‘ κ²°μ λ©΄μ λΆλνννμ¬ κ²°μ λ©΄κ³Ό λλ
Έμ
μ ννλ₯Ό μμ½κ² μ μ΄ν μ μλ€. λν μ’
μ λ§€κ° λ°©λ²μ λμ Miller-index κ²°μ λ©΄μ λμ κ· μΌλλ‘ μμ±ν μ μμΌλ―λ‘ λλ
Έ μ
μμ ννλ₯Ό μ μ΄νλ μ€μν μ λ΅μΌλ‘ μ¬μ©λλ€. μ°λ¦¬λ ν©μ±μ 첨κ°νλ μ κΈ° λΆμλ₯Ό λ³κ²½νμ¬ κΈ λλ
Έ μ
μμ μ±μ₯ λ° μΉ΄μ΄λμ± μ§νμ λν κ΄λ²μν μ΄ν΄λ₯Ό μ 곡νλ€. μ΄λ₯Ό μνμ¬ Ξ³-κΈλ£¨νλ°μμ€ν
μΈ(Ξ³-Glu-Cys) λ° μμ€ν
μ΄λκΈλ¦¬μ (Cys-Gly) μ μ¬μ©νμ¬ ν©μ±λ κΈ λλ
Έ μ
μμ μ±μ₯ κ²½λ‘μ ν€λμ± μ§νκ° κ²°μ νμ κ΄μ μμ λΆμλμλ€. Ξ³-Glu-Cysμ μ΄μ©νμ¬ ν©μ±λ κΈ λλ
Έ μ
μμ κ²½μ° λμΆλ μΉ΄μ΄λ λ κ°λ₯Ό κ°μ§λ μ μ‘면체 κ΅¬μ‘°λ‘ λ°λ¬νλ€. λ°λ©΄μ, Cys-Glyμ μ΄μ©νμ¬ ν©μ±λ λλ
Έμ
μμ κ²½μ° νμνμ 곡λ ꡬ쑰λ₯Ό κ°μ§ λ§λ¦λͺ¨κΌ΄ 12λ©΄μ²΄λ‘ λ°λ¬νλ©°, μ΄λ‘ μΈν΄ λ λλ
Έ μ
μλ μλ‘ λ€λ₯Έ μΉ΄μ΄λ κ΄ν λ°μμ 보μΈλ€. μκ°μ λ°λ₯Έ λλ
Έ μ
μμ μ±μ₯ λΆμμ ν΅ν΄ Ξ³-Glu-Cysμ Cys-Glyκ° μλ‘ λ€λ₯Έ μ€κ° ννλ₯Ό μ§λλ©° μμ±νλ€λ κ²μ μ μ μμλ€. Ξ³-Glu-Cysλ μ€λͺ©ν μ‘ν면체 λͺ¨μμ μ€κ°μ²΄λ₯Ό μ λνλ λ°λ©΄ Cys-Glyλ μ€λͺ©ν λ§λ¦λͺ¨κΌ΄ μμ΄λ©΄μ²΄μ μ€κ°μ²΄λ₯Ό 보μΈλ€. μ΄λ¬ν κ²°κ³Όλ ν©νμ΄λμ κΈ νλ©΄ κ°μ μνΈ μμ©μ μ΄ν΄ν¨μΌλ‘μ¨ μΉ΄μ΄λ ꡬ쑰μ κ·Έμ λ°λ₯Έ κ΄ν λ°μμ μ‘°μ ν μ μμμ μμ¬νλ€.
μ체 λΆμλ₯Ό μ΄μ©ν μΉ΄μ΄λ λλ
Έκ΅¬μ‘°μ ν©μ±μ μ£Όλ‘ νλΌμ¦λͺ¬ λ¬Όμ§μμ μ°κ΅¬λμ΄ μμ§λ§, μ΄λ§€ νμ±μ μ§λ
μΉ΄μ΄λ μ΄λ§€λ‘ μ¬μ©λ μ μλ μΉ΄μ΄λ κΈμ μ°νλ¬Όμ ν©μ±νλ €λ μλ λν μΉ΄μ΄λ λ¬Όμ§μ μμ© νλλ₯Ό μν μλ‘μ΄ λ°©ν₯μΌλ‘ μ μλκ³ μλ€. μ체 λΆμλ₯Ό μ΄μ©ν μΉ΄μ΄λ κΈμ μ°νλ¬Ό ν©μ±μμμ κΈ°μ‘΄ μ°κ΅¬λ λ¨μΌ μλ―Έλ
Έμ°μ κ΅νλμ΄ μμ§λ§, μΉ΄μ΄λμ± λ°λ¬μ μ΄ν΄νκ³ νμ₯ κ°λ₯ν ν©μ± μ λ΅μ μ립νκΈ° μν΄μλ ν©νμ΄λλ‘μ μμ΄ νμ₯μ΄ μꡬλλ€. λ³Έ μ°κ΅¬μμλ Tyr-Tyr-Cys ν©νμ΄λλ₯Ό μμ΄νμ₯μ μν 리κ°λλ‘ μ ννμ¬, μ½λ°νΈ μ°νλ¬Όμμ ν©νμ΄λλ₯Ό μ΄μ©ν μΉ΄μ΄λμ± λ°νμ νꡬνμλ€. ν©νμ΄λ 리κ°λλ₯Ό μ΄μ©νμ¬ ν©μ±λ μΉ΄μ΄λ μ½λ°νΈ μ°νλ¬Ό λλ
Έ μ
μλ μμΈμ λ° κ°μκ΄μ μμμμ 0.01μ λ°μ΄λ λΉλμΉ μΈμλ₯Ό λνλλ€. λν, 2D NMR λΆκ΄ λΆμμ ν΅ν΄ λλ
Έ μ
μ νλ©΄μ ν©νμ΄λ 리κ°λμ 3μ°¨μ μ
체ꡬ쑰λ₯Ό κ·λͺ
νμλ€. λν ν©νμ΄λ 리κ°λμ μνμ€μ λ°λ₯Έ μΉ΄μ΄λ μ½λ°νΈ μ°νλ¬Ό λλ
Έ μ
μμ λ°λ¬μ λΆμνμ¬ Tyr-Tyr-Cys 리κ°λμ μΈμ΄μ¬ κ·Έλ£Ήκ³Ό μΉ΄λ³΅μ€ κ·Έλ£Ήμ΄ μΉ΄μ΄λμ± λ°λ¬μ μ€μν μν μ λ΄λΉν¨μ κ·λͺ
νμλ€. λ³Έ μ°κ΅¬ κ²°κ³Όλ 무기 κ²°μ μ μΉ΄μ΄λμ±μ λ°ννλ ν©νμ΄λμ μν μ΄ μνΈ μμ©νλ λ¬Όμ§μ λ°λΌ λ¬λΌμ§ μ μμΌλ©°, μΉ΄μ΄λ κ΄ν νΉμ±μ λ³νλ₯Ό μΌκΈ°ν μ μμμ μμ¬νλ€.
λ¨μΌ νλΌμ¦λͺ¬ λλ
Έ μ
μμ κ΄ν μ νΈλ νλΌμ¦λͺ¬ 컀νλ§μ ν΅νμ¬ μ¦νλκ³ λ―Όκ°νκ² μ μ΄λ μ μλ€. μ¬λ¬ κ°μ νλΌμ¦λͺ¬ λλ
Έ μ
μκ° μΈμ ν κ²½μ°, μ
μ 곡λͺ
μ νΌμ±νκ° μΌμ΄λ 곡λͺ
μ ν¬κ² λ³νμν¨λ€. μ΄λ¬ν λ§₯λ½μμ, λ³Έ μ°κ΅¬μμλ νλΌμ¦λͺ¬ 컀νλ§μ μΉ΄μ΄λ νλΌμ¦λͺ¬ λλ
Έ μ
μμ μ μ©νμ¬ μΉ΄μ΄λ κ΄ν νΉμ±μ μ μ΄νκ³ μ νμλ€. μ΄λ₯Ό μνμ¬ μΉ΄μ΄λ κΈ λλ
Έ μ
μλ₯Ό κΈ°νμ μ½ν
νκ³ λλ
Έ ν¬κΈ°μ νλΌμ¦λͺ¬ κΈμ μΈ΅μ μ¦μ°©νμ¬ λ©ν λ¬Όμ§μ μ μνμλ€. νλΌμ¦λͺ¬ κ²°ν©μΌλ‘ μΈν κ΄ν νΉμ±μ λ³νλ ν¬κ³Ό κΈ°λ° λ° νμ° λ°μ¬ κΈ°λ° μνΈκ΄ μ΄μμ± (cirular dichroism, CD) λΆκ΄λ²μ ν΅ν΄ λΆμλμλ€. μΉ΄μ΄λ κΈμ λλ
Έ μ
μ κΈ°λ° λ©ν λ¬Όμ§μ κ΄νμ λΆμμ ν΅ν΄ CD μ€ννΈλΌμ νΌν¬ μμΉ, μΈκΈ° λ° λΆνΈκ° νλΌμ¦λͺ¬ 컀νλ§μ μν΄ λ³νν¨μ μ μ μμλ€. λν, νλΌμ¦λͺ¬ 컀νλ§μ μν΄ μμ±λ λͺ¨λλ λλ
Έκ΅¬μ‘°μ²΄μ ν¬κΈ°, 거리 λ° μ£Όλ³ κ΅΄μ λ₯ μ λ°λΌ ν¬κ² λ³ννμλ€. λ λμκ°, μΉ΄μ΄λ κΈ λλ
Έ μ
μμ μ€λ¦¬μΉ΄ μμ νλΌμ¦λͺ¬ λλ
Έμ
μμ κ΄ν νΉμ± λ° μμ μ±μ μ μ΄κ° κ°λ₯ν¨μ κ·λͺ
νμλ€.
λ³Έ νμ μ°κ΅¬μμλ λλ
Έ μ
μμ μΉ΄μ΄λμ± λ°λ¬μ ν©νμ΄λ 리κ°λκ° λ―ΈμΉλ μν μ μ΄ν΄ν¨μΌλ‘μ¨ λ¨μΌ λλ
Έ μ
μ μμ€μμ CD μ νΈμ μ μ΄λ₯Ό λ¬μ±νμλ€. λν νλΌμ¦λͺ¬ 컀νλ§μ μ¬μ©νμ¬ μΉ΄μ΄λ λλ
Έ ꡬ쑰μ κ΄νμ νΉμ±μ μ‘°μ νλ λ°©λ²λ‘ μ΄ ν립λμλ€. λ³Έ μ°κ΅¬λ₯Ό ν΅νμ¬ κ°λ°λ μΉ΄μ΄λ λλ
Έ ꡬ쑰μμ κ΄ν νΉμ±μ μ‘°μ μ μν λ°©λ²λ‘ μ μΉ΄μ΄λ λ©ν λ¬Όμ§μ μ€μ©μ μΈ κ΄ν μ₯μΉλ‘ ν΅ν©νλ κ²μ μ©μ΄νκ² ν κ²μΌλ‘ κΈ°λλλ€.Chiral metamaterials have been actively pursued in the field of nanophotonics due to their exceptional light-matter interactions. For decades, numerous attempts have been conducted to fabricate chiral nanostructure using state-of-the-art lithography techniques and molecular-assembly scaffolds. Possessing this geometric property, inorganic metal nanomaterials could exhibit fascinating physical phenomena which was difficult to be achieved in symmetric nanomaterials. Chiral nanostructures have greatly expanded the design to demonstrate chiroptic effects such as a negative refractive index, sensitive chiral sensing, and broad-band circular polarizer. In order to integrate the fascinating properties of chiral metamaterials into practical devices, it is necessary to achieve precisely defined chiral morphologies and chiroptic properties. However, the requirement for expensive facilities, the complexity of the process, and the limited resolution had restricted the translation of chiral metamaterials into real devices. Therefore, developing flexible methodologies for nanostructure control is important to address these limitations and provide new directions. Through this study, we propose that the diversification of nanoparticle morphology using peptide molecules and further modulation of the optical response utilizing plasmonic coupling of nanostructures can be a promising alternative to solve the above-mentioned limitations. In this thesis, we present a platform that can modulate the chiroptic response using plasmon coupling through understanding and regulation of the development of chiral nanostructures.
Recent study on the colloidal synthesis of plasmonic nanoparticles using biomolecules suggests that nanoparticles with novel morphology and optical property can be achieved by altering molecules, which are chirality encoders, involved during the synthesis. In addition, the optical response of a single plasmonic particle can be amplified and sensitively modulated using plasmon coupling. When several nanoscale plasmonic particles are adjacent to each other, hybridization of particle resonance is induced, which significantly changes the resonance. To establish new strategies for controlling the morphology and chirality of plasmonic nanostructures, we have first studied previous studies on bio-inspired pathways for complex nanostructures, focusing on the inorganic chirality induced by biomolecules in Chapter 2. Importantly, the interactions at the interface between biomolecules and inorganic surfaces provide an important insight into the evolution of chirality through atomic distortion or macroscopic reconstruction. Chapter 3 describes the experimental procedures, and Chapter 4, 5, and 6 describe the understanding and modulation of the chiroptic response from the two perspectives of single nanoparticles and systemic control.
Advances in nanomaterial engineering have enabled the development of colloidal synthesis methods for precise morphological control at the nanoscale. The use of various halide ions, metal ions and organic molecules as adsorbates can control the crystal facet and nanoparticle morphology by passivating the crystal facet with a specific Miller index. In addition, the seed-mediated method can synthesize high-Miller-index crystal facets with high uniformity, and thus is being used as an important strategy for controlling NP morphology. In this thesis, we have provided a broad understanding of the growth and chirality evolution in gold NPs by adjusting the type of additive molecules. We have analyzed the growth pathway and chirality evolution of the Ξ³-glutamylcysteine- (Ξ³-Glu-Cys-) and cysteinylglycine- (Cys-Gly-) directed gold NPs from a crystallographic perspective. Gold NPs developed into a cube-like structure with protruding chiral wings in the presence of Ξ³-Glu-Cys, whereas the NPs synthesized with Cys-Gly exhibited a rhombic dodecahedron-like outline with elliptical cavity structures, showing different chiroptic responses. Through time-dependent analysis, we reported that Ξ³-Glu-Cys and Cys-Gly generate different intermediate morphologies. Ξ³-Glu-Cys induced concave hexoctahedra-shaped intermediate, whereas Cys-Gly showed concave rhombic dodecahedra-shaped intermediate. These results showed that the chiral structure and resulting chiroptic response can be modulated through understanding the interaction between peptides and gold surfaces.
Molecule-directed synthesis of chiral nanostructure has been mainly studied in plasmonic materials, but attempts to synthesize chiral metal oxides that can be used as chiral catalysts due to their catalytic activity has been suggested as a new direction for expanding the application of chiral materials. Existing studies on the synthesis of chiral metal oxide using molecule have been limited to single amino acids, but sequence expansion with peptides is required to understand the chirality evolution and achieve a scalable synthetic strategy. In this thesis, Tyr-Tyr-Cys tripeptide including tyrosine and cysteine were selected as peptide ligands and the role of peptide in developing chirality in cobalt oxide was explored. Synthesized chiral cobalt oxide nanoparticles showed a g-factor of 0.01 in the UVβvisible region. In addition, the 3D conformation of the peptide ligand on the nanoparticle surfaces was identified by 2D NMR spectroscopy analysis. Furthermore, the sequence effect of Tyr-Tyr-Cys developing chiral cobalt oxide was analyzed, demonstrating that the thiol group and carboxyl group of the Tyr-Tyr-Cys ligand played an important role in chirality evolution. This results suggest that the role of the peptides can vary depending on the interacting material, leading to further variability in chiroptical properties.
The optical signal of a single plasmonic particle can be amplified and sensitively controlled using plasmon coupling. When several nanoscale plasmonic particles are adjacent to each other, hybridization of particle resonance occurs, which significantly changes the resonance. In this context, plasmonic coupling which has been mainly studied in achiral plasmon structures, was applied to chiral plasmonic nanoparticles to control chiroptical properties. In this thesis, we demonstrated the fabrication of metamaterial by coating chiral gold nanoparticles on a substrate and depositing a nanoscale plasmonic metal layer. In order to investigate changes in optical properties due to plasmon coupling, transmission-based and diffuse reflectance circular dichroism (CD) spectroscopy were utilized. Through this, it was confirmed that the resonance position, magnitude, and sign of the CD spectrum were changed by plasmon coupling. In addition, the coupled plasmon mode was significantly changed according to the dimension, distance, and refractive index of the nanostructure. Furthermore, synthesis of chiral gold-silica core-shell NPs enables versatile control of the structure and properties of plasmonic nanoparticles, facilitating their application to tailored plasmon coupling.
In conclusion, by understanding the role of peptides in nanoparticle development, CD manipulation has been achieved at the single nanoparticle level. In addition, a methodology for modulating the optical properties of chiral nanostructures using plasmon coupling has been established. We believe the development of versatile methodology for modulation of the chiroptical response in chiral nanostructures ultimately facilitate integration of the chiral metamaterials into practical optical devices.Chapter 1. Introduction 1
1.1 Chirality in Nature 1
1.2 Chiral Plasmonic Nanostructure 9
1.3 Objective of Thesis 21
Chapter 2. Fabrication of Chiral Inorganic Nanostructure and Its Optical Properties 24
2.1 Fabrication of Chiral Nanostructures using Hard Approach 24
2.2 Biomolecule-Directed Chiral Nanostructure 29
2.2.1 Biomolecule-Conjugated Inorganic Nanoparticles 29
2.2.2 Chirality Development by Biomolecule-Induced Local Distortion 36
2.2.3 Biomolecule-Directed Chiral Morphology 44
Chapter 3. Experimental Procedures 62
3.1 Synthesis of Chiral Gold Nanoparticles 62
3.2 Synthesis of Chiral Cobalt Oxide Nanoparticles 64
3.3 Synthesis of Chiral Gold-Silica Core-Shell Nanoparticles 66
3.4 Optical Characterization of Chiral Nanostructures 67
Chapter 4. Dipeptide-Directed Chiral Gold Nanoparticles 69
4.1 Introduction 69
4.2 Solution-Based Synthesis of Dipeptide-Directed Chiral NPs 72
4.3 Morphology Analysis of Ξ³-Glu-Cys- and Cys-Gly-directed NPs 79
4.4 Time-Dependent Analysis of Chiral Morphology Development 83
4.5 Concentration-Dependent Chiral Morphology and Chiroptical Responses 91
4.6 Sequence Effects 101
4.7 Conclusion 102
Chapter 5. Peptide-Directed Chiral Cobalt Oxide Nanoparticle 103
5.1 Introduction 103
5.2 Synthesis of Chiral Cobalt Oxide Nanoparticles using Tyr-Tyr-Cys 107
5.3 Effect of Synthetic Parameters on Chirality Development of Chiral Cobalt Oxide Nanoparticles 114
5.4 3D Conformation of Tyr-Tyr-Cys Ligand 120
5.5 Sequence Effect of the Tyr-Tyr-Cys 125
5.6 Magnetic Circular Dichroism in Chiral Cobalt Oxide Nanoparticles. 129
5.7 Conclusion 134
Chapter 6. Circular Dichroism Manipulation based on Plasmonic Coupling of Chiral Nanostructures 136
6.1 Introduction 136
6.2 Chiroptical Property of Helicoid-Based Plasmonic Nanostructure 138
6.3 Effect of Chiral Gap Structure 145
6.4 Spectral Manipulation through Structural Parameter Control 149
6.5 Synthesis of Chiral Gold-Silica Core-Shell Nanoparticles 151
6.6 Conclusion 154
Chapter 7. Concluding Remarks 155
References 159λ°