Pulsed Laser Ablation In Liquid Research Articles

Preparation of copper oxide nanosheets by pulsed laser ablation in liquid for anticancer, antioxidant, and antibacterial activities

In this work, the preparation of copper oxide (CuO) nanosheets by laser ablation in water was demonstrated. The optical, structural, stability, and morphological properties of CuO nanosheets were investigated using UV–Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscope (SEM), and zeta potential (ZP). The XRD results confirm the formation of crystalline (CuO) with a monoclinic phase. The optical energy gap of CuO nanosheets was found to be 2.2 eV at 300 k. The average thickness of the synthesized copper oxide nanosheets is 25 nm. Energy dispersive X-ray result confirms the formation of stoichiometric CuO. The zeta potential result confirms the synthesized CuO colloid is stable. Gram-positive bacteria are found to be more susceptible to CuO nanosheets than Gram-negative bacteria. The synthesized copper oxidenanosheets are tested for antibacterial activity against Gram (+ve) and Gram (-ve) bacteria stains. The results suggest that CuO NPS can give hydrogen atoms and remove the unstable electron from DPPH at a rate of 200 μg/ml than 12.50 μg/ml. The results demonstrate that the copper oxide nanosheets have an effective antioxidant. Furthermore, according to a cytotoxicity assay, when cancer cells are incubated with copper oxide nanosheets, they are unable to grow well. copper oxide nanosheets can induce apoptosis and suppress pancreatic cell proliferation.

Unraveling the Synergy of Anion Modulation on Co Electrocatalysts by Pulsed Laser for Water Splitting: Intermediate Capturing by In Situ/Operando Raman Studies.

Herein, the authors produce Co-based (Co3 (PO4 )2 , Co3 O4 , and Co9 S8 ) electrocatalysts via pulsed laser ablation in liquid (PLAL) to explore the synergy of anion modulation on phase-selective active sites in the electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Co3 (PO4 )2 displays an ultralow overpotential of 230mV at 10mAcm-2 with 48.5mVdec-1 Tafel slope that outperforms the state-of-the-art Ir/C in OER due to its high intrinsic activity. Meanwhile, Co9 S8 exhibits the highest HER performance known to the authors among the synthesized Co-based catalysts, showing the lowest overpotential of 361mV at 10mAcm-2 with 95.8mVdec-1 Tafel slope in the alkaline medium and producing H2 gas with ≈500mmol g-1 h-1 yield rate under -0.45V versus RHE. The identified surface reactive intermediates over in situ electrochemical-Raman spectroscopy reveal that cobalt(hydr)oxides with higher oxidation states of Co-cation forming under oxidizing potentials on the electrode-electrolyte surface of Co3 (PO4 )2 facilitate the OER, while Co(OH)2 facilitate the HER. Notably, the fabricated two-electrode electrolyzers using Co3 (PO4 )2 , Co3 O4 , and Co9 S8 electrocatalysts deliver the cell potentials ≈2.01, 2.11, and 1.89V, respectively, at 10mAcm-2 . This work not only shows PLAL-synthesized electrocatalysts as promising candidates for water splitting, but also provides an underlying principle for advanced energy-conversion catalysts and beyond.

Iron Oxide Nanoparticles (IONPs): Synthesis, Surface Functionalization, and Targeting Drug Delivery Strategies: Mini-Review

Iron oxide-based magnetic nanoparticles (IONPs) have received remarkable attention in a wide range of applications because of their unique physicochemical properties’ inheritance to the nanoscale. Among these nanoparticles (NPs), superparamagnetic iron oxide nanoparticles (SPIONs), as powerful noninvasive NPs, are widely used in nanomedicine applications such as targeted drug/ gene delivery, magnetic separation, cancer therapy, and magnetic resonance imaging (MRI) hyperthermia because of their superparamagnetic activity and remarkable small size. The synthesis of SPIONs and surface modification of these NPs for biological applications is an interesting research topic. These NPs have high magnetic susceptibility, a single magnetic domain, and a controlled magnetic behavior due to the SPION superparamagnetic feature. This review aims to explore the recently developed synthetic routes of SPIONs and show the best parameters to prepare SPIONs using pulsed laser ablation in liquid “PLAL” for biomedical applications. Furthermore, we highlight the properties, coating, and functionalization of SPIONs and their importance for biomedical applications, including targeted drug delivery and cancer therapy.

Prominent bactericidal characteristics of silver-copper nanocomposites produced via pulse laser ablation

This paper reports the characterization and antibacterial performance evaluation of some spherical and stable crystalline silver (Ag)/copper (Cu) nanocomposites (Ag-CuNCs) prepared in deionized water (DIW) using pulse laser ablation in liquid (PLAL) method. The influence of various laser fluences (LFs) on the structural, morphological, optical and antibacterial properties of these NCs were determined. The UV–Vis absorbance of these NCs at 403 nm and 595 nm was gradually increased accompanied by a blue shift. XRD patterns disclosed the nucleation of highly crystalline Ag-CuNCs with their face centered cubic lattice structure. TEM images showed the existence of spherical NCs with size range of 3–20 nm and lattice fringe spacing of approximately 0.145 nm. EDX profiles of Ag-CuNCs indicated their high purity. The antibacterial effectiveness of the Ag-CuNCs was evaluated by the inhibition zone diameter (IZD) and optical density (OD600) tests against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The proposed NCs revealed the IZD values in the range of 22–26 mm and 20–25 mm when tested against E. coli and S. aureus bacteria, respectively. The Ag-CuNCs prepared at LF of 14.15 J/cm2 revealed the best bactericidal activity. It is established that by controlling the laser fluence the bactericidal effectiveness of the Ag-CuNCs can be tuned.

Direct synthesis of hollow carbon nanoonion-like particles (HCNOs) decorated uniformly with Sn nanoparticles by long-pulse-width millisecond laser ablation of Sn target in n-hexane solution

The nanocomposites that composed of hollow carbon nanoonion-like particles (HCNOs) decorated with Sn quantum dots (QDs) (Sn QDs/HCNOs nanocomposites) were directly prepared by long-pulse-width millisecond laser ablation of pure Sn metal target immersed in n-hexane solution under room conditions. Low-resolution and High-resolution transmission electronic microscope (TEM) images not only reveal that the as-obtained products are composed of two homogeneously mixed phases, Sn QDs and HCNOs, but also the tight bonding of Sn QDs with the HCNOs. Moreover, Sn QDs/HCNOs composites have uniform morphology and narrow size distribution. The HCNOs present continuous imperfect onion-like structure with hollow cores and have a diameter in the range of 80–100 nm. The Sn QDs with a diameter in the range of 3–5 nm are distributed uniformly on the HCNOs. This work indicates that the pulsed laser ablation in liquid could be applied to the direct synthesis of HCNOs from the decomposition of liquid media via ‘bottom-up’ approach and in situ decoration of them due to the formation of pure metal Sn QDs via ‘top-down’ strategy.

One-step synthesis of Ti3+ self-doped CTO/rGO composites by pulsed laser ablation in liquid with enhanced photocatalytic activity in water purification

Titanate calcium integrated with reduced graphene oxide (CTO/rGO) composites are prepared using pulsed laser ablation in liquid (PLAL) technique. The laser wavelength exhibits a critical effect on the synthetic mechanism, which is primarily dominated by photothermal effect at 1064 nm but photochemical reactions at 355 nm. With the generation of Ti-O-C bond, the reduction of graphene oxide and the successful introduction of Ti3+ and oxygen vacancies, the bandgap of CTO/rGO composite can be significantly narrowed to 2.86 eV which has contributed to the generated·OH,·O2- and h+ of strong oxidation capacity to jointly achieve the efficient degradation of methyl orange. Our results demonstrate that CTO/rGO composites are able to endure severe conditions for an extended period of time and the pseudo-first-order constant of composites can be accomplished 15 times higher than pure titanate calcium. In view of the environment-friendly synthesis method and noticeable photocatalytic ability, the presented strategy is supposed to be a charming choice for removing organic pollutants from industrial wastewater.

Modelling of Pulsed Laser Ablation in Liquid via Monte Carlo techniques: The effect of laser parameters and liquid medium on the electron cloud

Pulsed Laser Ablation in Liquid (PLAL) is a method for nanoparticle synthesis in which electron clouds are involved in the ablation process by providing electron heating which increases ablation efficiency. To better understand and control PLAL, this process was modelled herein via the Monte Carlo technique and the pure jump algorithm approach. From this model, it was shown that picosecond lasers produce fewer electrons with lower kinetic energy density than femtosecond lasers within a typical material processing period that contains many pulses. It was found that photon energies of 100 eV resulted in a primary electron: secondary electron ratio of about 1 : 1.6 regardless of the number of simulated primary electrons. The maximum energy of the electron cloud during a 20 fs laser pulse with 100 eV photons was 0.05 keV regardless of the boundary condition (number of primary electrons). An increase in photon energy from 100 eV to 200 eV caused an increase of over 600% in electron cloud energy. Such an increase would be expected to have an influence on various materials processing applications. Repetition rates of 10–100 kHz were found to have no influence on the electron cloud dynamics originating from the related differences in temporal sequences.

A comprehensive review and outlook on the experimental techniques to investigate the complex dynamics of pulsed laser ablation in liquid for nanoparticle synthesis.

Pulsed laser ablation in liquid (PLAL) has been established as one of the most efficient and impactful methods for producing pure and ligand-free nanoparticles (NPs). PLAL has successfully been utilized for the synthesis of metal NPs, semiconductor NPs, ceramic NPs, and even nanocomposites. A variety of NPs, including core-shell, nanocubes, nanorods, and many other complex structures, can be synthesized using PLAL. The versatility associated with PLAL has led to the synthesis of NPs that have found applications in the field of biomedicine, sensing technology, energy harvesting, and various industries. Despite all the aforementioned advantages, there has been an ambiguity in terms of conditions/parameters for the nanoparticle synthesis as reported by various research groups. This has led to a perception that PLAL provides little or no control over the properties of the synthesized NPs. The properties of the NPs are reliant on transient dynamics caused due to a high-intensity laser's interaction with the target material. To understand the process of nanoparticle synthesis and to control the properties of NPs, it is critical to understand the various processes that occur during PLAL. The investigation of PLAL is essential for understanding the dynamical processes involved. However, the investigation techniques employed to probe PLAL present their own set of difficulties, as high temporal as well as spatial resolution is a prerequisite to probe PLAL. Hence, the purpose of this Review is to understand the dynamical processes of PLAL and gain an insight into the various investigation techniques and their data interpretation. In addition to the current challenges, some ways of overcoming these challenges are also presented. The benefits of concurrent investigations with special emphasis on the simultaneous investigation by multiple techniques are summarized, and furthermore, a few examples are also provided to help the readers understand how the simultaneous investigation works.

Green synthesis of TiO2@MWCNTs composites by pulsed laser ablation in liquid

Green synthesis of TiO2@MWCNTs composites by pulsed laser ablation in liquid

Graphene Nanostructures by Pulsed Laser Ablation in Liquids: A Review

High-quality graphene has demonstrated remarkable mechanical, thermal, electronic, and optical properties. These features have paved the road for the introduction of graphene into numerous applications such as optoelectronics and energy devices, photodegradation, bioimaging, photodetectors, sensors, and biosensors. Due to this, graphene research has accelerated exponentially, with the aim of reaching a sustainable large-scale production process of high-quality graphene that can produce graphene-based technologies at an industrial scale. There exist numerous routes for graphene fabrication; however, pulsed laser ablation in liquids (PLAL) has emerged as a simple, fast, green, and environmentally friendly method as it does not require the use of toxic chemicals. Moreover, it does not involve the use of expensive vacuum chambers or clean rooms. However, the great advantage of PLAL is its ability to control the size, shape, and structure of the produced nanostructures through the choice of laser parameters and liquid used. Consequently, this review will focus on recent research on the synthesis of graphene nanosheets and graphene quantum dots via PLAL and the effect of experimental parameters such as laser wavelength, pulse width, pulse energy, repetition rate, irradiation time, and liquid media on the produced nanostructures. Moreover, it will discuss extended PLAL techniques which incorporate other methods into PLAL. Finally, different applications that utilize nanostructures produced by PLAL will be highlighted. We hope that this review will provide a useful guide for researchers to further develop the PLAL technique and the fabrication of graphene-based materials.

Plasmonically enhanced two-photon absorption induced photoacoustic microscopy with laser-synthesized TiN nanoparticles

Combining photonic excitation and acoustic detection, photoacoustic imaging (PAI) presents one of the most promising noninvasive biomedical diagnostic modalities, but this technique still lacks efficient nano-sized contrast agents absorbing light in the region of relative tissue transparency (630–900 nm). Here, we explore the use of titanium nitride (TiN) nanoparticles (NPs) fabricated by methods of pulsed laser ablation in liquids as a contrast agent in PAI. When prepared in acetone, the NPs are spherical, have an average size of 25 nm, and exhibit a broad plasmonic absorption peak around 700 nm. We show that solutions of these NPs render possible a strong nonlinear photoacoustic response and the generation of photoacoustic images with 67 μm resolution within the biological transparency window. The observed effect is explained by a plasmonically enhanced two-photon absorption process in TiN NPs. Combined with earlier demonstrated capability of generating photothermal therapeutic effect, relative chemical purity, and excellent biocompatibility, laser-synthesized TiN NPs promise attractive applications in biomedical theranostics involving imaging modalities based on photoacoustics microscopy or tomography.

Highly efficient UV–visible absorption of TiO2/Y2O3 nanocomposite prepared by nanosecond pulsed laser ablation technique

Nanostructured TiO 2 -based composites are promising materials because of their superior optical, structural, and electronic properties relative to pristine nanostructured TiO 2 . The enhanced properties of TiO 2 -based composites have been used in several important applications such as gas sensors, solar cells, and photocatalytic applications. In the past, numerous materials have been coupled with TiO 2 to enhance their optical properties. In this work, full-spectrum (UV and Visible) responsive TiO 2 /Y 2 O 3 nanocomposite has been synthesized via pulsed laser ablation in liquid (PLA) to study the impact of Y 2 O 3 on the structural, morphology, and optical property of the TiO 2 . The nanostructured composites prepared were characterized by XRD, Raman spectroscopy, Field-Emission Scanning Electron Microscope (FESEM) attached with Energy-Dispersive X-ray spectroscopy (EDX), Photoluminescence, XPS, and UV–Vis absorbance spectra. The result demonstrates that the coupling Y 2 O 3 with TiO 2 not only changes the structural, optical, and morphology of the TiO 2 but also significantly amplified the light absorption characteristics of the TiO 2 within the UV and visible region. The synthesized TiO 2 /Y 2 O 3 nanocomposite could potentially be useful for visible-light responsive applications.

Decorated chitosan with silver-zinc nanoparticles by pulse laser ablation

The chitosan/Ag/Zn nanocomposites were synthesized in an environmentally friendly and inexpensive method using pulsed laser ablation in liquids, an Nd-YAG laser with a wavelength of 1064 nm, 300 mJ/pls, and 1000 pulses for silver plate, and 500 mJ/pls with the same wavelength for zinc plate.The UV–vis absorbance and estimated optical properties, FESEM and FTIR, show that the Ag/Zn nanoparticles were successfully decorated with a chitosan chain. The nanocomposite promised to be used as an antibiotic.

Enhanced photocatalytic degradation of methylene blue by nanocomposites prepared by laser ablation of Bi on CNT-α-Fe2O3 nanoparticles

The low conductivity and high combination rate of photogenerated electrons (e-) and photogenerated holes (h+) are the real challenges of photocatalysis. These problems could be mitigated by the synthesis of heterostructured nanocomposites (NCs). In this study, Bi@CNT-Fe2O3 nanocomposite was fabricated via pulsed laser ablation in liquid and characterized by UV–Vis spectroscopy, photoluminescence (PL), X-ray diffraction (PXRD) and field scanning electron microscopy (FESEM). These techniques revealed successfully the formation of CNT-α-Fe2O3 and Bi@CNT-α-Fe2O3 nanocomposites. The photocatalytic activities of the Fe2O3, CNT-α-Fe2O3, and Bi@CNT-Fe2O3 photocatalysts were evaluated by the degradation of methylene blue (MB) dye under ultraviolet (UV) light irradiation in the presence of a very low concentration of hydrogen peroxide (H2O2) as an oxidizing agent. The results show that the Bi@CNT-α-Fe2O3 NC has the highest photocatalytic degradation efficiency of MB which completes in 20 min of UV light irradiation. In addition, the obtained rate constants (min−1) of Bi@CNT-α-Fe2O3 NC were 1.3 and 3.4 times higher than those of CNT-α-Fe2O3 and α-Fe2O3. nanocatalysts, respectively.

Synthesis of gallium nitride nanostructure using pulsed laser ablation in liquid for photoelectric detector

Gallium nitride (GaN) thin film was grown by Nd: YAG pulsed laser ablation with two laser ablation energies. The optical band gaps and crystallinities of the specimens were studied to determine the optimal energy applied. The obtained results ensure that the physical properties of the prepared samples are directly related to the used laser energy. The XRD result exhibited three peaks of hexagonal GAN (h-GaN) nano-particles at 2θ = 34.54°, 37.49° and 48.19 from the (002), (100) and (200) planes, respectively. The ablation energy of 1600 mJ showed a high peak intensity. The samples fabricated at laser energy of 1400 mJ showed the maximum energy bandgap of 3.62 eV at room temperature. High-performance GaN/Si photo-detector was prepared using a drop casting. The spectral response was approximately 2.34 Am/W, and device detectivity was approximately 557.887 × 1012 cm Hz1/2 W−1 in the UV spectral region.

Gold Nanoparticles Ablated in Ethanol: Topographical and Morphological Properties for Refractive Index Sensors

The impact of wavelength of the laser on several Topographical and Morphological characteristics of gold nanoparticles (Au NPs) was ablated utilizing pulsed laser ablation in liquid in this work. We employed a gold target with an extra purity to ablate the Nano-particles and a removal of tattoo Nd:YAG Q switching pulsed laser with a 10 Ns duration of pulses, the energy are 1000 mJ, the number of pulses are 600 pulses, and a frequency of 3 Hz to explore the gold NPs' characteristics using TEM and AFM. According to the greatest intensity of shorter wavelengths.

Synthesis of "Naked" TeO2 Nanoparticles for Biomedical Applications.

Chalcogenide nanoparticles have become a very active field of research for their optoelectronic and biological properties. This article shows the production of tellurium dioxide nanoparticles (TeO2 NPs) by pulsed laser ablation in liquids. The produced nanoparticles were spherical with a diameter of around 70 nm. The energy band gap of those nanoparticles was determined to be around 5.2 eV. Moreover, TeO2 NPs displayed a dose-dependent antibacterial effect against antibiotic-resistant bacteria such as multidrug-resistant Escherichia coli (MDR E. coli) and methicillin-resistant Staphylococcus aureus (MR S. aureus). The “naked” nature of the nanoparticle surface helped to eradicate the antibiotic-resistant bacteria at a very low concentration, with IC50 values of ∼4.3 ± 0.9 and 3.7 ± 0.2 ppm for MDR E. coli and MR S. aureus, respectively, after just 8 h of culture. Further, the IC50 values of the naked TeO2 NPs against melanoma (skin cancer) and healthy fibroblasts were 1.6 ± 0.7 and 5.5 ± 0.2 ppm, respectively, for up to 72 h. Finally, to understand these optimal antibacterial and anticancer properties of the TeO2 NPs, the reactive oxygen species generated by the nanoparticles were measured. In summary, the present in vitro results demonstrate much promise for the presently prepared TeO2 NPs and they should be studied for a wide range of safe antibacterial and anticancer applications.

Metal clusters trapped on opaque substrate particles prepared using pulsed laser ablation in liquid

Gold clusters trapped on opaque substrate particles were produced using pulsed laser ablation. The ablation laser irradiated the target Au plate in a liquid dispersed with opaque substrate particles. It was found that the rate of thermal diffusion from the smaller particle that absorbed laser energy was greater than that from the larger particle; therefore, it is less likely to increase the temperature. Subsequently, the Au target was ablated more efficiently than the opaque substrate particles dispersed in the liquid. Therefore, the opaque particles were barely miniaturized and remained intact. The interaction mechanism of the deposition of the Au particle produced by laser ablation on the substrate particles was investigated by measuring the zeta potential of the substrate particles. The positively charged Au particles were adsorbed by ion exchange with positively charged Y2O3 substrate particles. In contrast, they interacted via electrostatic interactions with negatively charged α-quartz and ZSM-5 zeolite particles.

Influence of Laser Process Parameters, Liquid Medium, and External Field on the Synthesis of Colloidal Metal Nanoparticles Using Pulsed Laser Ablation in Liquid: A Review.

Pulsed laser ablation in liquid, used for nanoparticle synthesis from solid bulk metal targets (a top-down approach), has been a hot topic of research in the past few decades. It is a highly efficient and ‘green’ fabrication method for producing pure, stable, non-toxic (ligand-free), colloidal nanoparticles, which is often challenging using traditional chemical methods. Due to the short time scale interaction between the laser pulses and the target, it is difficult to achieve complete control on the physical characteristics of metallic nanoparticles. Laser process parameters, liquid environment, and external fields vastly effect the shape and structure of nanoparticles for targeted applications. Past reviews on pulsed laser ablation have focused extensively on synthesising different materials using this technique but little attention has been given to explaining the dependency aspect of the process parameters in fine-tuning the nanoparticle characteristics. In this study, we reviewed the state of the art literature available on this technique, which can help the scientific community develop a comprehensive understanding with special insights into the laser ablation mechanism. We further examined the importance of these process parameters in improving the ablation rate and productivity and analysed the morphology, size distribution, and structure of the obtained nanoparticles. Finally, the challenges faced in nanoparticle research and prospects are presented.

Graphene thin film microextraction and nanoparticle enhancement for fast LIBS metal trace analysis in liquids

Several strategies have been effectively tested in the past to improve the Laser Induced Breakdown Spectroscopy (LIBS) signal for the analysis of liquid samples, involving peculiar experimental configurations, such as Double Pulse LIBS (DP-LIBS). Recently, sample treatment has proven to be a viable and simple way to enhance the performances of LIBS towards the analysis of solutions. Among the various strategies, the most promising and versatile appears to be Thin Film Microextraction (TFME) using carbon-based adsorbents.Another sample pre-treatment procedure, Nanoparticle-Enhanced LIBS (NELIBS), has gained significant interest due to its relative simplicity and effectiveness. This methodology uses a deposition of silver nanoparticles (AgNPs) on the sample to greatly increase the emission of the LIBS plasma.In this work, we investigate for the first time the possibility of combining TFME and NELIBS. We developed TFME supports by depositing an aqueous graphene nano-sheets (aq-GRA) prepared by Pulsed Laser Ablation in Liquid (PLAL) on a glass substrate. The preparation of the supports was optimized with regards to the substrate nature, deposition method, sorbent volume and drying method. Then, the TFME supports were tested for the extraction of Chromium from aqueous solution at different extraction times and analyte concentration. Subsequently, the TFME supports were treated with a deposition of silver nanoparticles (AgNP) to test the feasibility of the NELIBS approach.We observed an enhancement in the emission lines of Cr when the AgNPs were applied, as well as a lower estimated LOD value when compared to plain graphene TFME supports.