Laser Ablation Synthesis In Solution Research Articles

Advancements in on-site heavy metal detection: Characterizing and sensitive Hg2+ sensing of silver spheroid nanoparticles obtained by laser ablation synthesis in solution

Heavy metal detection in water bodies is crucial to prevent potential harm to the environment, animals and humans. While powerful techniques such as atomic absorption spectrometry exist, they often require extensive sample preparation and are typically confined to laboratory settings. As a result, alternative detection methods such as optical sensors, are under development to provide a simpler, faster, and on-site detection solution. In the present work spheroidal silver nanoparticles (AgNPs) with a mean size of 14.7 ± 0.6 nm were synthesized by laser ablation in a sodium citrate solution. These nanoparticles exhibit a localized surface plasmon resonance (LSPR), which is profoundly dependent on the size, morphology and composition of the nanoparticles and the refractive index of the surrounding media. The detection capabilities of these nanoparticles were assessed by exposing them to various metal ions, revealing a distinctive sensitivity to Hg2+ ions. Notably, this particular ion had a significant impact on the extinction curve of the AgNPs. The impact of synthesis parameters, including sodium citrate and NaCl concentration, as well as pH, on the efficacy of Hg2+ detection was systematically studied. Characterization techniques such as Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), High-Resolution TEM (HRTEM), and Scanning Transmission Electron Microscopy (STEM) were employed to determine the size, morphology, distribution, crystalline structure, and elemental composition of the AgNPs. The results indicated that AgNPs synthesized through laser ablation in a sodium citrate solution exhibited sensitive detection capabilities for Hg2+ ions, reaching an LOD and LOQ of 0.9355 μM and 2.8350 μM respectively.

Titanium Dioxide Nanomaterial Ink Production Through Laser Ablation Synthesis in Solution for Printed Electronics Applications

Flexible and printed electronics have become increasingly popular as they make possible the production of flexible, low‐cost, multifunction devices that are unachievable through traditional manufacturing methods. The printed films are significantly impacted and thus limited by the existing ink production process. Herein, an alternate technique of generating high‐quality titanium dioxide (TiO2) nanoparticle ink compatible with aerosol jet printing using laser ablation synthesis in solution (LASiS) is showcased. Dynamic light scattering data and transmission electron microscopy confirm the particle size distribution. UV–vis measurements are performed, and the Beer–Lambert relationship is used to determine the concentration of the generated ink. The inks generated at two different repetition rates are compared: 200 kHz and 1 MHz. X‐Ray diffraction analysis of the aerosol jet printed thin film post‐thermal sintering confirms the grain size and phase purity of the printed thin films. This work demonstrates the effectiveness of the LASiS technique in producing printable nanoparticle inks with little‐to‐no postprocessing.

Fe-carbide/Fe-oxide-based nanocomposites synthesized as magnetic nanomaterials via laser ablation synthesis in solution (LASiS)

Magnetic nanostructured materials (MNMs) have gained prominence in materials technology developments owing to their potential biomedical applications for hyperthermia cancer treatment, and transplant organ cryopreservation. Herein, we report the facile and cost-effective synthesis of Fe-based composite MNMs, comprising both Fe@Fe2O3 and Fe3C@C core-shell nanoparticles (NPs), via Laser Ablation Synthesis in Solution (LASiS) using Fe targets ablated under acetone and toluene. Detailed materials characterizations using electron microscopy-based imaging, diffraction studies, and spectroscopic analyses - including Raman and Mössbauer spectroscopy - relate the structure-composition properties for different Fe-oxide/carbide phases in the aforesaid MNMs to their respective magnetic responses. Specifically, we confirm the presence of ultra-small (2–10 nm) amorphous Fe-oxide NPs, as well as Fe@Fe2O3 core-shell NPs (20–40 nm) in the samples synthesized by ablating Fe under acetone. In contrast, samples synthesized under toluene indicate a higher concentration of Fe3C@C core-shell NPs (20–40 nm) with a relatively low concentration of Fe2O3 NPs (2–10 nm). Furthermore, the crystallinity of the metallic phases and carbonaceous shell coatings are systematically increased by carrying out LASiS under heated toluene (up to ∼95 °C). Mössbauer spectroscopy results indicate that the elevation in toluene temperature leads to an increase in the concentrations of Fe3C@C NPs from ∼40 % to ∼53 % (at.).

Production of Silver Nano-Inks and Surface Coatings for Anti-Microbial Food Packaging and Its Ecological Impact

Food spoilage is an ongoing global issue that contributes to rising carbon dioxide emissions and increased demand for food processing. This work developed anti-bacterial coatings utilising inkjet printing of silver nano-inks onto food-grade polymer packaging, with the potential to enhance food safety and reduce food spoilage. Silver nano-inks were synthesised via laser ablation synthesis in solution (LaSiS) and ultrasound pyrolysis (USP). The silver nanoparticles (AgNPs) produced using LaSiS and USP were characterised using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, UV-Vis spectrophotometry and dynamic light scattering (DLS) analysis. The laser ablation technique, operated under recirculation mode, produced nanoparticles with a small size distribution with an average diameter ranging from 7-30 nm. Silver nano-ink was synthesised by blending isopropanol with nanoparticles dispersed in deionised water. The silver nano-inks were printed on plasma-cleaned cyclo-olefin polymer. Irrespective of the production methods, all silver nanoparticles exhibited strong antibacterial activity against E. coli with a zone of inhibition exceeding 6 mm. Furthermore, silver nano-inks printed cyclo-olefin polymer reduced the bacterial cell population from 1235 (±45) × 106 cell/mL to 960 (±110) × 106 cell/mL. The bactericidal performance of silver-coated polymer was comparable to that of the penicillin-coated polymer, wherein a reduction in bacterial population from 1235 (±45) × 106 cell/mL to 830 (±70) × 106 cell/mL was observed. Finally, the ecotoxicity of the silver nano-ink printed cyclo-olefin polymer was tested with daphniids, a species of water flea, to simulate the release of coated packaging into a freshwater environment.

Additive-free silver nanoparticle ink development using flow-based Laser Ablation Synthesis in Solution and Aerosol Jet printing

• Optimum conditions determined for high yield LASiS Ag NP at 1.08 mg mL −1 . • Process control developed for Ag particle production in range of 27–39 nm. • Aerosol Jet printing of LASiS Ag NP for supercapacitor and humidity sensor. • Track resistance of 83 Ω improved to 51 Ω after thermal sintering treatment. • Resistivity of 7.72 × 10 −6 Ω m −1 improved to 4.74 × 10 −6 Ω m −1 for sintered tracks. Additive free conductive ink formulation via green techniques and its direct printing is critical for many applications including smart electronics, solar cells, healthcare and electrochemical energy storage. The available printable ink generations are far away from ideal. This study reports the development of additive free silver (Ag) nano particle (NP) inks via flow-based Laser Ablation Synthesis in Solution (LASiS) system and Aerosol Jet printing. Examples of LASiS Ag NP printed tracks and patterns on unprocessed glass, rubber, and plastic substrates with spatial uniformity and high printing resolution are demonstrated. For thermally sintered Ag NP track, the resistivity decreased to 4.74 × 10 −6 Ω m and conductivity improved to 2.11 × 10 5 S/m. The track resistance of ≈ 83 Ω improved to ≈ 51 Ω and the resistivity of 7.72 10 −6 Ω m (conductivity: 1.29 × 10 5 S/m) improved to 4.74 × 10 −6 Ω m. This work highlights that LASiS is a versatile, additive-free conductive ink formulation method for the scalable production of next generation printed electronic components and devices, using the emerging Aerosol Jet printing technology.

Nanoparticle production via laser ablation synthesis in solution method and printed electronic application - A brief review

With the evolution of additive manufacturing and flexible printed electronic (PE) technologies, conductive inks have received a lot of interest. Nanomaterials are an important component of conductive ink composition. LASIS (Laser Ablation Synthesis in Solution) is a physical method for creating nanoparticles in a liquid environment. This top-down technique employs well-known laser-based technologies to generate additive-free nanocolloids that are less harmful and more ecologically friendly. This study discusses recent advancements in the manufacturing of LASiS nanomaterials and their printed electronic applications. The parameters that determine the yield and attributes of LASiS nanoparticles are examined, with emphasis on specific use of such nanoparticles as conductive inks in the field of printed electronics. The advantages of LASiS-synthesised nanoparticles in printing applications, as well as the challenges that must be resolved to reach optimum performance, are also explored.

Silver Nano-Colloid Characterization for Printing Application

Silver nano-colloids have been generated via Laser Ablation Synthesis in Solution (LASiS) system. Nanoparticle formation with particle size below 50 nm in DI water was confirmed using UV-VIS spectroscopy, Dynamic Light Scattering (DLS) technique, and transmission electron microscopy (TEM). Supercapacitor structure, having dimension 11 mm x 10 mm, was successfully Aerosol Jet printed on an untreated polymer substrate using as produced LASiS silver nano-colloid.

Human tau fibrillization and neurotoxicity in the presence of magnesium oxide nanoparticle fabricated through laser ablation method

In this study, the acceleratory effect of magnesium oxide nanoparticles (MgO NPs) on the amyloid fibrillization of human tau protein, a major protein involved in the onset of Alzheimer’s disease (AD) was investigated. The MgO NPs were fabricated through laser ablation synthesis in solution (LASiS), well-characterized, and explored further for tau aggregation and relevant neurotoxicity by different assays. The results showed that the MgO NPs have a size of around 30 nm, a hydrodynamic radius of 57.09 nm, and a zeta potential of −18.06 mV. The data from ThT and ANS fluorescence-based assays along with circular dichroism (CD) spectroscopy clearly indicated that MgO NPs could significantly promote tau fibrillization, concentration-dependently. Considering the acceleratory effect of MgO NPs against tau fibrillization, cellular assays including cell viability, reactive oxygen species (ROS), and caspase-3 assays indicated that the neurotoxicity of tau amyloid fibrils formed with MgO NPs was higher than that of tau samples aged alone against N2a neuron-like cells. Therefore, it was concluded that the interaction of MgO NPs with tau can lead to acceleration of tau aggregation and underlying neurotoxicity. This study, then can provide useful information about the direct effect of MgO NPs against memory proteins and subsequent adverse effects.

Infrared pulsed fiber laser-produced silver-109-nanoparticles for laser desorption/ionization mass spectrometry of carboxylic acids

Application of monoisotopic cationic 109Ag nanoparticles (109AgNPs) obtained by PFL (pulsed fiber laser) 2D GS (galvo-scanner) LASiS (laser ablation synthesis in solution) for high resolution laser desorption/ionization mass spectrometry and mass spectrometry imaging of carboxylic acids is presented. Six acids, azelaic, 3-methylhippuric, linoleic, oleic, arachidic and erucic acid were used as test compounds for quantification with a MALDI-type mass spectrometer. Comparison of commonly made manual measurements with semi-automatic MSI was performed providing very interesting findings. Carboxylic acids were directly tested in 1 000 000-fold concentration change conditions ranging from 1 mg/mL to 1 ng/mL, which equates to 300 ng to 300 fg of carboxylic acid per measurement spot. Methods were also tested on samples of spiked human blood serum for quantification of carboxylic acids and verification of the influence of biological matrix on the measurement.

Silver nanocolloid generation using dynamic Laser Ablation Synthesis in Solution system and drop-casting

Conductive inks allow for low cost and scalable deposition of conductive tracks and patterns for printed electronics. Metal nanoparticle colloids are a novel form for producing conductive inks. Laser Ablation Synthesis in Solution (LASiS) is a “green” method for the production of metal nanoparticle colloids without the need for environmentally hazardous chemicals, however the method has typically been limited by its low production rates. This study reports on the generation of an additive free silver nanocolloid with maximized productivity using a flow-based LASiS system and its characterization using dynamic light scattering, UV–VIS, transmission electron microscopy and field emission scanning electron microscopy. The productivity of the LASiS silver nanoparticle (size ∼34 ± 5 nm) was ∼0.9 mg mL−1. While the flow-based system achieves high laser ablation rates in the mass of nanomaterial generated per unit time, the volume of liquid required for the flow leads to relatively low concentrations. Therefore, in this work, LASiS concentrated ink was formulated via a centrifugal method, which was then drop-cast and heat treated to produce a conductive silver layer. Centrifuging to concentrate the ink was shown to be a necessary step to achieve good results, with the lowest resistance across the drop-cast material of 60.2 Ω after annealing.

Laser Ablation Synthesis in Solution and Nebulization of Silver-109 Nanoparticles for Mass Spectrometry and Mass Spectrometry Imaging.

Preparation of monoisotopic silver-109 nanoparticles (109AgNPs) by pulsed fiber laser (PFL) ablation synthesis in solution (LASiS) with the use of a 2D galvoscanner (2D GS) is described. The procedure of covering of custom-made stainless-steel MALDI targets containing studied objects via nebulization is also presented. Examples of application of the new method (PFL-2D GS LASiS and nebulization) in mass spectrometry (MS) analyses and MS imaging (MSI) are shown. These include tests with a nonionic nucleoside and saccharide, ionic amino acids, and also a low-molecular-weight polymer. Fingerprint MS imaging is shown as an example of a fast and simple MSI procedure.

A New Nanocomposite Packaging Based on LASiS-Generated AgNPs for the Preservation of Apple Juice.

Designing bioactive materials, with controlled metal ion release, exerting a significant biological action and associated to low toxicity for humans, is nowadays one of the most important challenges for our community. The most looked-for nanoantimicrobials are capable of releasing metal species with defined kinetic profiles, either by slowing down or inhibiting bacterial growth and pathogenic microorganism diffusion. In this study, laser ablation synthesis in solution (LASiS) has been used to produce bioactive Ag-based nanocolloids, in isopropyl alcohol, which can be used as water-insoluble nano-reservoirs in composite materials like poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Infrared spectroscopy was used to evaluate the chemical state of pristine polymer and final composite material, thus providing useful information about synthesis processes, as well as storage and processing conditions. Transmission electron microscopy was exploited to study the morphology of nano-colloids, along with UV-Vis for bulk chemical characterization, highlighting the presence of spheroidal particles with average diameter around 12 nm. Electro-thermal atomic absorption spectroscopy was used to investigate metal ion release from Ag-modified products, showing a maximum release around 60 ppb, which ensures an efficient antimicrobial activity, being much lower than what recommended by health institutions. Analytical spectroscopy results were matched with bioactivity tests carried out on target microorganisms of food spoilage.

Effects of Different Surfactant Charges on the Formation of Gold Nanoparticles by the LASiS Method.

The laser ablation synthesis in solution (LASiS) method has been widely utilized due to its significant prospects in laser microprocessing of nanomaterials. In this study, the LASiS method with the addition of different surfactant charges (cationic CTAB, nonionic TX-100, and anionic SDS) was used to produce Au NPs. An Nd:YAG laser system at 532 nm excitation with some synthetic parameters, including different laser fluences, ablation times, and surfactant concentrations was performed. The obtained Au NPs were characterized by UV-Vis spectroscopy, transmission electron microscopy, and zeta potential analyzer. The Au NPs exhibited the maximum absorption peak at around 520 nm for all samples. The color of Au NPs was changed from red to reddish by increasing the laser fluence. The surfactant charges also played different roles in the Au NPs’ growth during the synthesis process. The average sizes of Au NPs were found to be 8.5 nm, 5.5 nm, and 15.5 nm with the medium containing CTAB, TX-100, and SDS, respectively. Besides, the different surfactant charges induced different performances to protect Au NPs from agglomeration. Overall, the SDS and CTAB surfactants exhibited higher stability of the Au NPs compared to the Au NPs with TX-100 surfactant.

Kinetically Stable Nonequilibrium Gold-Cobalt Alloy Nanoparticles with Magnetic and Plasmonic Properties Obtained by Laser Ablation in Liquid.

Nonequilibrium nanoalloys are metastable solids obtained at the nanoscale under nonequilibrium conditions that allow the study of kinetically frozen atoms and the discovery of new physical and chemical properties. However, the stabilization of metastable phases in the nanometric size regime is challenging and the synthetic route should be easy and sustainable, for the nonequilibrium nanoalloys to be practically available. Here we report on the one-step laser ablation synthesis in solution (LASiS) of nonequilibrium Au-Co alloy nanoparticles (NPs) and their characterization on ensembles and at the single nanoparticle level. The NPs are obtained as a polycrystalline solid solution stable in air and water, although surface cobalt atoms undergo oxidation to Co(II). Since gold is a renowned plasmonic material and metallic cobalt is ferromagnetic at room temperature, these properties are both found in the NPs. Besides, surface conjugation with thiolated molecules is possible and it was exploited to obtain colloidally stable solutions in water. Taking advantage of these features, an array of magnetic-plasmonic dots was obtained and used for surface-enhanced Raman scattering experiments. Overall, this study confirms that LASiS is an effective method for the formation of kinetically stable nonequilibrium nanoalloys and shows that Au-Co alloy NPs are appealing magnetically responsive plasmonic building blocks for several nanotechnological applications.

Real-time monitoring and control for high-efficiency autonomous laser fabrication of silicon nanoparticle colloids

Nanotechnology is a significant research tool for biological and medical research with major advancements achieved from nanoparticle (Np) applications in biosensing and biotherapeutics. For laser ablation synthesis in solution (LASiS) to be chosen by researchers for Np colloid production, the process must effectively compete with chemical synthesis in terms of produced colloid quality and productivity while taking advantage of LASiS benefits in terms of its ‘green-synthesis’ and single-step functionalisation abilities. In this work, a newly developed integrated LASiS Np manufacturing system is presented including a Np flow reactor design, an at-line Np size monitoring via 180° dynamic light scattering, and a UV-Vis spectroscopy system used to estimate colloid concentration and stability. The experimental outcomes are discussed in terms of Np productivity and quality via these at-line measurements from the UV-Vis and DLS systems. The developed instrument was validated via off-line SiNps DLS, UV-Vis and morphology tests via TEM. Ultra-high quality and nanoparticle fabrication rate efficiency was achieved and is reported here.

MOF-derived PtCo/Co3O4 nanocomposites in carbonaceous matrices as high-performance ORR electrocatalysts synthesized via laser ablation techniques

ZIF-67-derived carbon-based bimetallic nanocomposites with reduced Pt-loading via laser ablation synthesis in solution (LASiS) as a superior electrocatalyst for oxygen reduction reaction (ORR).

Electrochemical and chronoamperometry assessment of nano‑gold sensor surfaces produced via novel laser fabrication methods

New developments in laser ablation have shown great potential as nanofabrication methodologies, offering many significant advantages over more traditional methods. Herein, we have developed a method for applying two of these techniques, confined atmospheric pulsed-laser (CAP) deposition and laser ablation synthesis in solution (LASiS), to the fabrication of a nanostructured sensor platform. Following deposition, additional steps were then used to crosslink the deposited nanostructures and fabricate counter and reference electrodes. Chronoamperometry and cyclic voltammetry (CV) were used to assess the effects of these crosslinking steps on the properties of the sensor surfaces. These experiments resulted in the development of a simple, inexpensive and readily scalable process for the fabrication of 3-electrode sensor systems. As an example of a readily measurable surface interaction, electrochemical impedance spectroscopy (EIS) was applied to demonstrate the use of these systems in the detection of 6-mercaptohexanol. This interaction was examined in real-time by measuring the change in the EIS of the sensor system over time following its exposure to the thiol. This experiment clearly showed a measurable EIS response, demonstrating the effectiveness of these newly fabricated sensors for the detection of a simple surface interaction and suggesting the future potential of these laser based methods as the basis for an inexpensive, facile, rapid and scalable sensor fabrication process. • Development of a novel, inexpensive, scalable, laser based method for the fabrication of nanostructured biosensors. • Comparison of several sensor designs from various stages of the development process. • Demonstration of basic sensor activity using chronoamperometry and electrochemical impedance spectroscopy. • Examination of the effects of a key fabrication step on the properties of the sensor surface.

Red ruby glass from gold nanoparticles obtained by LASiS – a new approach.

Currently, most of the red colored glasses are still produced using cadmium sulfoselenide, despite its high toxicity. Alternative solutions, more environmentally friendly, have been sought, most of them going through the use of gold or copper nanoparticle, the color being obtained by striking.This work presents a new methodology for production of a red colored glass by the incorporation of gold nanoparticles in the melt, trying to take advantage of an amorphous silica layer involving the nanoparticles. Gold nanoparticles (AuNP) were produced by laser ablation synthesis in solution (LASiS), using a solution of tetraethyl orthosilicate (TEOS) and isopropanol (IPA).A xerogel was prepared using the TEOS:IPA:AuNp suspension, mixed with a alkaline-earth aluminosilicate colorless glass and melted at 1350 °C producing a glass with an intense and homogeneous ruby red color without the need of a striking stage.

Stable nano-silver colloid production via Laser Ablation Synthesis in Solution (LASiS) under laminar recirculatory flow

ABSTRACT As nanomaterials find applications in an increasingly diverse range of fields such as wastewater treatment, biotechnology and flexible electronics, the demand for nanomaterials with specific properties has increased. This increase is coupled with an increasing emphasis on nanomaterials with highly specific properties for specialised applications. Industrially, nanomaterials are produced via wet-chemical techniques which employ the use of solvents and reagents which are environmentally harmful. As we move forward with the use of nanomaterials, the ability to produce nanomaterials in a sustainable manner has become a topic of great significance. Towards this end, Laser Ablation Synthesis in Solution (LASiS) is a physical production technique capable of producing tailored nanomaterial colloids in a sustainable manner. These colloids are produced by ablating a solid target immersed in a solvent using a laser. Typically, LASiS is conducted in a batch process and in small volumes limiting commercial viability. To overcome this, there has been a move towards the use of continuous production via LASiS using flow systems. This allows an increase in nanomaterial yield, resulting in colloid concentrations approaching those of commercial colloids. This work investigates a new production technique incorporating a laminar recirculatory flow system to produce stable high concentration nano-silver colloids.

Synthesis and Shape Manipulation of Anisotropic Gold Nanoparticles by Laser Ablation in Solution

Anisotropic gold nanostructures are attracting attention due to the strong correlation between their shape and the localized surface plasmon resonances, which allows tuning their optical responses through morphological optimizations. Laser ablation synthesis in solution usually produces stable gold nanospheres colloids without any surfactant, which is important for their easy functionalization. Nevertheless, obtaining anisotropic nanoparticles with this technique is still a challenge, and few examples show that a postsynthesis approach is usually required. We show that a single pulse laser ablation allows the synthesis of anisotropic branched gold nanoparticles through careful control of the number of laser pulses interacting with the generated nanoparticles. It is shown that the very first pulses considerably affect the morphology of the ablated nanomaterial. Moreover, also the fluence above the ablated target is found to have an important role in the final nanoparticle morphology. The study of the interaction between the nanostructures and the laser pulses is achieved using an inflow setup. The optical extinction behavior of the produced anisotropic gold nanostructures was rationalized using boundary element method (BEM) based calculations, by considering the contributions from several morphologies, which were found to be in good agreement with experimental observations.