Name: Synthesizing Metal Nanoparticles and Nanostructures Using Ultrafast Laser Ablation
Uploaded: 2023-06-16T14:20:00
Description: Watch this Scientific Journal Video about Synthesizing Metal Nanoparticles and Nanostructures Using Ultrafast Laser Ablation at JoVE.com

synthesizing metal nanoparticles and nanostructures using ultrafast laser ablation

Laser Ablation을 통한 나노입자와 나노구조체 합성

Ultrafast laser ablation is a rapidly evolving field of laser-material interactions. High-intensity laser pulses with pulse durations in the femtosecond (fs) to picosecond (ps) range are used to generate precise material ablation. Compared to nanosecond (ns) laser pulses, ps laser pulses can ablate materials with higher precision and accuracy due to their shorter pulse duration. They can generate less collateral damage, debris, and contamination of the ablated material due to fewer thermal effects. However, ps lasers are typically more expensive than ns lasers and need specialized expertise for operation and maintenance. The ultrafast laser pulses enable precise control over the energy deposition, which leads to highly localized and minimized thermal damage to the surrounding material. Additionally, ultrafast laser ablation can lead to the generation of unique nanomaterials (i.e., surfactants/capping agents are not obligatory during the production of nanomaterials). Therefore, we can term this a green synthesis/fabrication method1,2,3. The mechanisms of ultrafast laser ablation are intricate. The technique involves different physical processes, such as (a) electronic excitation, (b) ionization, and (c) the generation of a dense plasma, which results in the ejection of material from the surface4. Laser ablation is a simple single-step process to produce nanoparticles (NPs) with high yield, narrow size distribution, and nanostructures (NSs). Naser et al.5 conducted a detailed review of the factors influencing the synthesis and production of NPs through the laser ablation method. The review covered various aspects, such as the parameters of a laser pulse, focusing conditions, and the ablation medium. The review also discussed their impact on producing a wide range of NPs using the laser ablation in liquid (LAL) method. The laser-ablated nanomaterials are promising materials, with applications in various fields such as catalysis, electronics, sensing, and biomedical, water splitting applications6,7,8,9,10,11,12,13,14.
Surface-enhanced Raman scattering (SERS) is a powerful analytical sensing technique that significantly enhances the Raman signal from probe/analyte molecules adsorbed onto metallic NSs/NPs. SERS is based on the excitation of surface plasmon resonances in metallic NPs/NSs, which results in a significant rise in the local electromagnetic field near the metallic nano-features. This enhanced field interacts with the molecules adsorbed on the surface, significantly enhancing the Raman signal. This technique has been used to detect various analytes, including dyes, explosives, pesticides, proteins, DNA, and drugs15,16,17. In recent years, significant progress has been made in the development of SERS substrates, including the use of differently shaped metallic NPs18,19 (nanorods, nanostars, and nanowires), hybrid NSs20,21 (a combination of the metal with other materials&#160;such as Si22,23, GaAs24, Ti25, graphene26, MOS227, Fe28, etc.), as well as flexible substrates29,30 (paper, cloth, nanofiber, etc.). Developing these new strategies in the substrates has opened up new possibilities for using SERS in various real-time applications.
This protocol discusses the fabrication of Ag NPs using a ps laser at different wavelengths and Ag-Au alloy NPs (with different ratios of Ag and Au targets) fabricated using laser ablation technique&#160;in distilled water. Additionally, silicon micro/nanostructures are created using an fs laser on silicon in the air. These NPs and NSs are characterized using ultraviolet (UV)-visible absorption, transmission electron microscopy (TEM), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). Furthermore, the preparation of SERS substrates and analyte molecules are discussed, followed by the collection of Raman and SERS spectra of the analyte molecules. Data analysis is performed to determine the enhancement factor, sensitivity, and reproducibility of the laser-ablated NPs/NSs as potential sensors. Additionally, typical SERS studies are discussed, and the SERS performance of hybrid substrates is evaluated. Specifically, it has been found that the promising gold nanostars&#39; SERS sensitivity can be enhanced approximately 21 times by using laser-structured silicon instead of plain surfaces (such as Si/glass) as a base.

저자 스포트라이트: Advancements and Applications in Nanoparticle Synthesis Through Laser Ablation in Liquids 

표면 강화 라만 산란 기반 감지 응용 분야를 위한 초고속 레이저 절제 나노 입자 및 나노 구조

Laser ablation and liquids technique focuses on synthesizing nanoparticles and nanostructures by ablating a target material in liquid or gas environment, forming ecofriendly nanoparticles without any surfactants. This research scope involves refining the laser parameters, analyzing nanoparticle properties, exploring synthesis mechanisms, and discovering applications in various fields such as catalysis, sensing, electronics, energy storage, and biomedical imaging. Recent developments in laser ablation for nanomaterial fabrication involve tailoring the nanoparticle sizes, shapes, and composition, scalable production methods, hybrid nanomaterial synthesis, and surface functionalization.These advances offer improved stability, extended shelf life, high scalability that is up to few grams per hour, and commercially viable colloidal nanoparticles and surface nanostructures production for diverse applications. In recent times, various other improvisations such as ultrafast vessel beam and vortex beam ablation processes have been implemented to generate exotic nanostructures, as well as nanoparticles, with tuneable shapes, sizes, and topographies. Technologies advancing nanoparticle synthesis via ultrafast laser ablation include molecular dynamic simulations for understanding the formation of these nanoparticles.Precise control for tailoring nanoparticle size, shape, and composition in C.2 TEM characterization and real time monitoring techniques. The experimental challenges involved are automation techniques through improved instrumentation and technology, addressing the initial establishment cost of the laser ablation technique itself, ensuring proper sample preparation, controlling the contamination, and announcing data analysis and interpretation for increased accuracy and reliability of the results. In our laboratory, we have investigated diverse materials such as gold, silver, zinc, titanium, copper, silicone, gallium arsenide, germanium, graphene oxide, Hafnium, and various biome metallic, trimetallic, and plus monoxides.Laser ablation experiments were conducted in different environments using various focusing conditions for precise material processing and nanoparticle synthesis.

Watch this Scientific Journal Video about Synthesizing Metal Nanoparticles and Nanostructures Using Ultrafast Laser Ablation at JoVE.com

Synthesizing Metal Nanoparticles and Nanostructures Using Ultrafast Laser Ablation  

초고속 레이저 절제를 이용한 금속 나노입자 및 나노구조 합성

시작하려면 대상 재료와 주변 액체를 선택하십시오. 아세톤을 사용하여 대상 표면을 15분 동안 초음파 세척하여 오일, 그리스 및 왁스와 같은 유기 물질을 제거합니다. 표면을 에탄올로 15분 더 초음파 세척하여 소금과 설탕과 같은 극성 오염 물질을 제거합니다.그런 다음 15분 동안 초음파 세척을 사용하여 탈이온수로 표면을 청소하여 샘플 표면에서 잔류 용매나 오염 물질을 제거합니다. 절제 전에 샘플의 무게를 측정한 다음 샘플에 대해 레이저 절제 실험을 수행합니다. 절제 실험 후 샘플의 무게를 다시 측정합니다.절제 전과 후의 샘플 무게를 비교하여 실험 중에 제거된 물질의 양을 추정합니다. 다음으로, 은 표적의 피코초 레이저 절제를 위해 입력 레이저 출력을 약 150밀리와트로 조정합니다. 편광판과 반파장판을 결합하여 레이저 펄스 에너지를 조정합니다.포커싱 렌즈를 사용하여 레이저 빔을 샘플에 집중시켜 재료 표면을 제거합니다. Z 방향의 변환 스테이지를 사용하여 샘플에 대한 레이저의 초점을 수동으로 조정하면서 생성된 밝은 플라즈마와 발산되는 균열 소리를 관찰합니다. 다음으로, 다양한 절제 깊이를 달성하고 나노 입자 및 나노 구조 합성에 대한 제어를 개선하는 데 따라 레이저 빔을 샘플에 집중시키기 위해 집속 광학을 사용합니다.샘플을 XY 스테이지에 배치하여 ESP 컨트롤러에 연결된 s가 레이저 전파 방향에 수직으로 이동하도록 합니다. 스캔 속도와 레이저 처리 영역을 조정하여 샘플과 상호 작용하는 레이저 펄스의 수를 최적화합니다. 레이저 어블레이션 과정에서 샘플을 스캔하는 동안 레이저 패터닝을 수행하여 원하는 치수를 얻고 단일 지점 어블레이션을 방지합니다.다음으로, 액체에서 레이저 절제의 경우 레이저 절제 실험을 수행합니다. 일관성을 유지하기 위해 레이저 출력 및 기타 설정을 모니터링합니다. 실험 중에 대상 물질을 지속적으로 관찰하여 레이저 빔이 원하는 영역에 초점을 유지하도록 합니다.은 콜로이드 나노 입자의 흡수 스펙트럼은 표면 플라스민 공명 피크가 서로 다른 레이저 파장에 대해 420, 394 및 403 나노 미터에서 관찰되었음을 밝혔습니다. 조성이 다른 은금 합금 나노 입자의 정규화 된 흡광도 스펙트럼은 금 비율이 0에서 100으로 증가함에 따라 표면 플라스민 공명 피크 이동을 410에서 519 나노 미터로 나타 냈습니다.

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Synthesizing Metal Nanoparticles and Nanostructures Using Ultrafast Laser Ablation

Ultrafast Laser-Ablated Nanoparticles and Nanostructures for Surface-Enhanced Raman Scattering-Based Sensing Applications

The technique of ultrafast laser ablation in liquids has evolved and matured over the past decade, with several impending applications in various fields ...