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

Sintetizando nanopartículas e nanoestruturas via ablação a laser

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.

Autor em destaque: Avanços e aplicações na síntese de nanopartículas por meio da ablação a laser em líquidos 

Nanopartículas e nanoestruturas ultrarrápidas abladas a laser para aplicações de sensoriamento baseado em espalhamento Raman aprimorado por superfície

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  

Sintetizando Nanopartículas e Nanoestruturas Metálicas Usando Ablação Ultrarrápida a Laser

Para começar, escolha o material alvo e o líquido circundante. Realize a limpeza ultrassônica da superfície alvo usando acetona por 15 minutos para remover materiais orgânicos, como óleos, graxas e ceras. Sujeite a superfície à limpeza ultra-sônica com etanol por mais 15 minutos para remover contaminantes polares como sais e açúcares.Em seguida, limpe a superfície com água deionizada usando limpeza ultrassônica por 15 minutos para remover quaisquer solventes residuais ou contaminantes da superfície da amostra. Meça o peso da amostra antes da ablação e, em seguida, realize um experimento de ablação a laser na amostra. Medir o peso da amostra novamente após o experimento de ablação.Estimar a quantidade de material removido durante o experimento comparando o peso da amostra antes e após a ablação. Em seguida, ajuste a potência do laser de entrada para aproximadamente 150 miliwatts para ablação a laser de picossegundo do alvo de prata. Combine um polarizador e uma placa de meia onda para ajustar a energia do pulso do laser.Focalize o feixe de laser na amostra usando uma lente de focalização para abater a superfície do material. Ajuste manualmente o foco do laser na amostra usando um estágio de translação na direção Z enquanto observa o plasma brilhante produzido e o som de rachadura emanando. Em seguida, use óptica de focalização para focar o feixe de laser na amostra, dependendo de alcançar diferentes profundidades de ablação e melhorar o controle sobre a síntese de nanopartículas e nanoestruturas.Posicione a amostra no estágio XY conectado a um controlador ESP, garantindo que ela se mova perpendicularmente à direção de propagação do laser. Ajuste a velocidade de varredura e a área de processamento a laser para otimizar o número de pulsos de laser interagindo com a amostra. Durante o processo de ablação a laser, execute a padronização a laser durante a varredura da amostra para atingir as dimensões desejadas e evitar a ablação de ponto único.Em seguida, para ablação a laser em líquido, realizar um experimento de ablação a laser. Monitore a potência do laser e outras configurações para manter a consistência. Observe continuamente o material alvo durante o experimento, garantindo que o feixe de laser permaneça focado na área desejada.Os espectros de absorção das nanopartículas coloidais de prata revelaram que picos de ressonância de plasminas de superfície foram observados em 420, 394 e 403 nanômetros para diferentes comprimentos de onda de laser. Os espectros de absorbância normalizados de nanopartículas de liga de ouro de prata com diferentes composições revelaram um deslocamento do pico de ressonância de plasmina de superfície de 410 para 519 nanômetros à medida que a porcentagem de ouro aumentou de zero para 100.

Research

JoVE Journal

Engineering

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 ...