Laser Ablation Research Articles

Mechanistic insights into waterjet-guided laser grooving of silicon: Impact of ablation dynamics, oxide formation, and thermal stress

Waterjet-guided laser machining of silicon offers precision with minimal heat-affected zones (HAZs), but understanding the mechanisms behind laser-material interactions remains essential. This study first utilizes orthogonal experiments to reveal fundamental relationships between processing parameters (scanning cycle, laser fluence, scanning velocity, and waterjet pressure) on groove depth and the depth-to-HAZ ratio. These findings guide the in-depth investigation of laser-material mechanisms. The results indicate that the ablation rate decreases with increasing scanning cycles, a phenomenon primarily attributed to the different absorption rates of 532 nm laser light between silicon and silicon dioxide. This conclusion is supported by x-ray photoelectron spectroscopy(XPS) results, which reveal that the accumulation of silicon dioxide occurs as the scanning cycles increase. Additionally, a near-linear relation between the ablation rate and laser fluence is observed, as the ablated area is continuously exposed to high laser intensity regions. However, increasing laser fluence also leads to diminished processing quality due to greater thermal deformation in non-ablating regions. Last, increased scanning velocity is found to cause rougher surfaces, as insufficient heat diffusion leads to higher thermal stress and results in micro-crack formations. The results provide a detailed understanding of the laser-induced transformations in the material and highlight optimal conditions for reducing thermal damage while maintaining machining efficiency. This study advances the field of laser processing by offering insights into the mechanisms governing oxide formation, thermal cracking, and material deformation during silicon grooving, providing the foundation for future exploration of laser-material interaction dynamics.

Silver nanoparticles doped MoS2 flakes as highly efficient electrocatalyst for hydrogen evolution reaction

Hydrogen fuel-based economy has been a prime candidate for sustainable future. Hydrogen generation through water splitting is quite popular, and it has the potential to produce green hydrogen at a very low cost. The development of low-cost, high efficiency electrocatalysts is very important for water splitting processes. Hence, this paper focuses on a novel approach to develop low-cost silver (Ag) nanoparticles doped molybdenum disulfide (MoS2) electrocatalyst for hydrogen evolution reaction (HER). The HER activity of pristine MoS2 nanostructures has also been tested to compare the results with Ag-MoS2 nanocomposites. The materials (MoS2, Ag-MoS2) have been synthesized using pulsed laser ablation in liquid, which is a sustainable technique to synthesize nanomaterials. The developed electrocatalysts have been characterized using various techniques such as scanning electron microscopy, energy dispersive x-ray spectroscopy, UV-Vis spectroscopy, and x-ray diffraction to know their morphology, optical properties, and structural properties. The electrochemical performance study was analyzed in a standard three electrode cell with 0.5M H2SO4. From electrochemical measurement study, it has been observed that Ag-MoS2 has an overpotential of 0.222 V, which is less than that of MoS2 nanosheets (0.274 V). The Tafel slope is also the least for Ag-MoS2 as compared to MoS2. The charge transfer resistance for Ag-MoS2 is 13.05 Ω, while MoS2 provides the resistance of 39.93 Ω. The developed Ag-MoS2 electrocatalyst may be a promising material to generate green hydrogen at the industrial scale.

Fabrication of hafnium-based nanoparticles and nanostructures using picosecond laser ablation

This work presents a unique and straightforward method to synthesise hafnium oxide (HfO2) and hafnium carbide (HfC) nanoparticles (NPs) and to fabricate hafnium nanostructures (NSs) on a Hf surface. Ultrafast picosecond laser ablation of the Hf metal target was performed in three different liquid media, namely, deionised water (DW), toluene, and anisole, to fabricate HfO2 and HfC NPs along with Hf NSs. Spherical HfO2 NPs and nanofibres were formed when Hf was ablated in DW. Hf ablated in toluene and anisole demonstrated the formation of core–shell NPs of HfC with a graphitic shell. All NPs exhibited novel optical reflectance properties. Reflectance measurements revealed that the fabricated NPs had a very high and broad optical absorption throughout the UV–vis–NIR range. The NPs synthesised in toluene exhibited the best absorption. The successful fabrication of Hf NSs with the formation of laser-induced periodic surface structures (LIPSS) with low spatial frequency (LSFL) and high spatial frequency (HSFL) orthogonal to each other was also demonstrated. The LSFL and HSFL both exhibited quasi-periodicity. This work presents a simple way to fabricate HfO2 and HfC NPs and provides insight into their morphological and optical characteristics paving way for their applications in future.

Simulation of the temperature distribution of kidney stones induced by thulium fiber laser and Ho: YAG laser lithotripsy.

Simulation studies on temperature distribution in laser ablation help predict ablation rates, laser settings, and thermal damage. Despite the limited number of reported numerical studies on the temperature distribution of kidney fluid, there is no simulation study for kidney stone temperature distribution. We employ a numerical approach to study the kidney stone temperature distribution and predict ablation rates, which is an important parameter for clinical lithotripsy. The study looked at how the thulium fiber laser and the Ho:YAG laser differ in terms of temperature profile and ablation depth of kidney stones like calcium oxide monohydrate. The ablation depth increased from 152.7µm to 489.7µm when the TFL laser (operated at 10Hz repetition rate and 1ms pulse width) fluence increased from 764J/cm2 to 1146J/cm2. Correspondingly, the depth increased from 21µm to 68µm for the Ho: YAG laser operated at 3Hz and 0.22ms pulse width. We attribute this to an increase in temperature with laser energy. We further investigated the effect of pulse width on ablation depth by considering three different TFL pulse widths: 0.5ms, 0.75ms, and 1ms. There was a decrease in ablation depths from 402.5µm to 242.6µm when the pulse width increased from 0.5ms to 1ms. Because of lower water absorption coefficients, the Ho:YAG laser (70mJ/10Hz) produced a smaller ablation depth and temperature profile than the thulium fiber laser (70mJ/10Hz). Experimental results from the literature validated the simulation. We found that the Ho:YAG laser worked better for ablation when it was set to 0.2J/100Hz for the Ho:YAG laser and 0.4J/50Hz for the TFL laser, which were clinical laser settings that we found in the literature. This indicates that, in addition to laser absorption by water, the laser parameters also significantly influence temperature distribution and ablation.

The Trace-Element Characteristics of Chrysoberyl: Insights from Compositional and Spectroscopic Analyses

To characterize the trace-element characteristics of chrysoberyl, we studied twenty-six chrysoberyl samples from various localities by using laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS), photoluminescence (PL), and ultraviolet–visible–near-infrared (UV–Vis–NIR) spectroscopy. Chemical analysis has confirmed the existence of trace elements, including Fe, Ti, Ga, Sn, B, Cr, and V. The phenomenon of ionic isomorphic substitution frequently occurs at lattice sites within chrysoberyl. Notably, the isomorphic substitution of Al3+ in octahedral sites is significant, with the primary substituting elements being Fe, Ti, Cr, V, Ga, and Sn. The PL spectra of chrysoberyl samples exhibit sharp peaks at 678 and 680 nm, which are attributed to Cr3+, even in samples in which the Cr concentration is below the detection limit of LA-ICP-MS. This demonstrates the high-sensitivity feature of PL spectroscopy. The UV–Vis–NIR spectra of chrysoberyl samples consistently exhibit a band at 440 nm, and strong double narrow bands near 367 nm and 375 nm are observed. These spectral features are associated with Fe3+ chromophores—specifically, Fe3+-Fe3+ pairs or clusters and Fe3+ ions, respectively. By combining LA–ICP–MS analysis and PL mapping on a sample exhibiting color zoning, it has been found that the darker sections contain a higher concentration of Cr compared to the lighter sections, while the concentrations of other elements remain largely consistent. In other words, subtle variations in Cr concentration may be the underlying cause of color zoning in chrysoberyl.

IR Pulsed Laser Ablation of Carbon Materials in High Vacuum

This work aimed to understand how the energy released by short laser pulses can produce different effects in carbon targets with different allotropic states. The IR pulse laser ablation, operating at 1064 nm wavelength, 3 ns pulse duration, and 100 mJ pulse energy, has been used to irradiate different types of carbon targets in a high vacuum. Graphite, highly oriented pyrolytic graphite, glassy carbon, active carbon, and vegetable carbon have exhibited different mass densities and have been laser irradiated. Time-of-flight (TOF) measurements have permitted the evince of the maximum carbon ion acceleration in the generated plasma (of about 200 eV per charge state) and the maximum yield emission (96 μg/pulse in the case of vegetal carbon) along the direction normal to the irradiated surface. The ion energy analyzer measured the carbon charge states (four) and their energy distributions. Further plasma investigations have been performed using a fast CCD camera image and surface profiles of the generated craters to calculate the angular emission and the ablation yield for each type of target. The effects as a function of the target carbon density and binding energy have been highlighted. Possible applications for the generation of thin films and carbon nanoparticles are discussed.

Laser melting, evaporation, and fragmentation of nanoparticles: Experiments, modeling, and applications

This review examines the processes of laser heating, melting, evaporation, fragmentation, and breakdown of metal nanoparticles, as well as the dependences and values of the threshold laser parameters that initiate these processes. Literature results are analyzed from experimental studies of these processes with gold, silver, and other nanoparticles, including laser surface melting and evaporation of nanoparticles and Coulomb fragmentation of nanoparticles by ultrashort laser pulses. A theoretical model and description of the thermal mechanisms of mentioned processes with metal (solid) nanoparticles in a liquid (solid) medium, initiated by the action of laser pulses with the threshold fluences, are presented. Comparison of the obtained results with experimental data confirms the accuracy of the model and makes it possible to use them to evaluate the parameters of laser thermal processing of nanoparticles. Applications of the processes include the laser melting, reshaping, and fragmentation of nanoparticles, the formation of nanostructures and nanonetworks, the laser processing of nanoparticles located on substrates, and their cladding on surfaces in various laser nanotechnologies. The use of laser ignition, combustion, and incandescence of nanoparticles is discussed, as is the use of nanoparticle-triggered laser breakdown for spectroscopy. These laser processes are used in photothermal nanotechnologies, nanoenergy, laser processing of nanoparticles, nonlinear optical devices, high-temperature material science, etc. In general, this review presents a modern picture of the state of laser technology and high-temperature processes with nanoparticles and their applications, being focused on the latest publications with an emphasis on recent results from 2021–2024.

Structural characterization of AlCuFe icosahedral quasicrystal nanoparticles synthesized using femtosecond laser ablation

Structural characterization of AlCuFe icosahedral quasicrystal nanoparticles synthesized using femtosecond laser ablation

Experimental Study on the Propulsion Performance of Laser Ablation Induced Pulsed Plasma

This study investigates the influence of electromagnetic fields on the propulsion performance of laser plasma propulsion. Based on the principle of pulsed plasma thrusters, an electromagnetic field is utilized to accelerate laser plasma, achieving enhanced propulsion performance. This approach represents a novel method for the electromagnetic enhancement of laser propulsion performance. In this paper, pulsed plasma thrusters induced by laser ablation are employed. The generated plasma is subjected to the Lorentz force under the influence of an electromagnetic field to obtain higher speed, thus increasing impulse and specific impulse. An experimental platform for laser-ablation plasma electromagnetic acceleration was constructed to explore the enhancement effect of discharge characteristics and propulsion performance. The results demonstrate that increased laser energy has little effect on discharge characteristics, while the trend of propulsion performance parameters initially rises and then declines. After coupling the electromagnetic field, the propulsion performance is significantly enhanced, with stronger electromagnetic fields yielding more pronounced effects.

Topography immune-responsive silk films for skin regeneration.

Scar formation and chronic refractory wounds pose a significant threat to public health, with abnormal immune regulation as a key characteristic. However, topography, a crucial factor influencing immune responses, has not been adequately considered in the design of wound dressings. In this study, we constructed a hierarchical structure on silk fibroin (SF) films by combining soft lithography and femtosecond laser ablation, without altering the intrinsic properties of SF. The discontinuity in the hierarchical structure induced a transformation in the morphology of macrophage RAW264.7 cells from round to spindle or pancake-like shapes, leading to phenotypic polarization toward M2 or M1. The timely transition from M1 to M2 polarization and the balance between these states promoted fibroblast L929 cells to express mRNA for FN, coll-I, TGF-β1, and α-SMA. The hierarchical structure of SF films facilitates full-thickness wound repair in vivo by regulating inflammation and promoting neovascularization and collagen deposition. Thus, hierarchical topography presents a promising strategy for the design of immunomodulatory wound dressings.

Leveraging Femtosecond Laser Ablation for Tunable Near-Infrared Optical Properties in MoS2-Gold Nanocomposites.

Transition metal dichalcogenides (TMDCs), particularly molybdenum disulfide (MoS2), have gained significant attention in the field of optoelectronics and photonics due to their unique electronic and optical properties. The integration of TMDCs with plasmonic materials allows to tailor the optical response and offers significant advantages for photonic applications. This study presents a novel approach to synthesize MoS2-Au nanocomposites utilizing femtosecond laser ablation in liquid to achieve tunable optical properties in the near-infrared (NIR) region. By adjusting ablation and fragmentation protocols, we successfully synthesize various core-shell and core-shell-satellite nanoparticle composites, such as MoS2/MoSxOy, MoSxOy/Au, and MoS2/MoSxOy/Au. UV-visible absorption spectroscopy unveils considerable changes in the optical response of the particles depending on the fabrication regime due to structural modifications. Hybrid nanoparticles exhibit enhanced photothermal properties when subjected to NIR-I laser irradiation, demonstrating potential benefits for selective photothermal therapy. Our findings underscore that the engineered nanocomposites not only facilitate green synthesis but also pave the way for tailored therapeutic applications, highlighting their role as promising candidates in the field of nanophotonics and cancer treatment.

Second Intention Healing After Laser Ablation of Benign Eyelid Margin Tumors

ABSTRACT Purpose This study aims to present the therapeutic outcomes of benign eyelid margin tumors treated with laser ablation, offering an alternative approach to traditional shaving biopsy. Methods In all patients, tumors were eliminated through either laser ablation or shaving biopsy. Comparative analysis was conducted between two patient groups: the laser-assisted ablation group (Group 1) and the shaving excision surgery group (Group 2). A total of 66 patients with 67 benign eyelid margin tumors were retrospectively included in this study (2019–2023). Thity-four cases underwent laser ablation, and 33 cases were subjected to shaving excision biopsy. Postoperatively, histologic confirmation was obtained in 11 out of the 33 cases that underwent shaving excision. Results In Group 1, no functional or cosmetic complications were observed. The wound margin was clear after laser-assisted ablation in all cases. In Group 2, there was one instance of eyelid notching, loss of cilia, and two pigmentations. No wound infections were reported. The average wound epithelialization duration was 3.3 weeks in Group 1, significantly faster than 4.2 weeks in Group 2 (p < .01). The average lesion size was 3.0 × 2.9 mm in Group 1, significantly smaller than 3.5 × 3.4 mm in Group 2 (p < .05). No recurrences were observed during the follow-up period. Conclusions Laser ablation for small benign eyelid margin tumors may be a favorable alternative to shaving excision biopsy surgery. All patients were satisfied with the cosmetic result. There was no definitive postoperative or intraoperative complication during or after laser application.

KATP channel–dependent electrical signaling links capillary pericytes to arterioles during neurovascular coupling

The brain has evolved mechanisms to dynamically modify blood flow, enabling the timely delivery of energy substrates in response to local metabolic demands. Several such neurovascular coupling (NVC) mechanisms have been identified, but the vascular signal transduction and transmission mechanisms that enable dilation of penetrating arterioles (PAs) remote from sites of increased neuronal activity are unclear. Given the exponential relationship between vessel diameter and blood flow, tight control of arteriole membrane potential and diameter is a crucial aspect of NVC. Recent evidence suggests that capillaries play a major role in sensing neural activity and transmitting signals to modify the diameter of upstream vessels. Thin-strand pericyte cell bodies and processes cover around 90% of the capillary bed, and here we show that these cells play a central role in sensing neural activity and generating and relaying electrical signals to arterioles. We identify a KATP channel-dependent neurovascular signaling pathway that is explained by the recruitment of thin-strand pericytes and we deploy vascular optogenetics to show that currents generated in individual thin-strand pericytes are sent over long distances to upstream arterioles to cause dilations in vivo. Genetic disruption of vascular KATP channels reduces the arteriole diameter response to neural activity and laser ablation of thin-strand pericytes eliminates the KATP-dependent component of NVC. Together, our findings indicate that thin-strand pericytes sense neural activity and transform this into KATP channel-dependent electrometabolic signals that inform upstream arterioles of local energy needs, promoting spatiotemporally precise energy distribution.

Management of twin-reversed arterial perfusion (TRAP) sequence: a systematic review and meta-analysis.

Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twin pregnancies characterized by placental anastomoses between a normally developed twin and an acardiac mass. Though several treatment modalities exist, the optimal management strategy is unclear. This study aims to compare the various treatment strategies for TRAP sequence. A systematic review of the literature was performed using PRISMA guidelines including PubMed, Scopus, Web of Science and the Cochrane Library. Studies were imported into Covidence, where they were independently screened by two authors. Studies included described interventions for TRAP sequence. Those excluded were unavailable in English and lacked differentiation between intervention strategies for TRAP and other monochorionic twin pregnancies. Fisher's exact test and random effects modeling were used for statistical analysis. 2340 abstracts were screened, of which 218 articles progressed to full review and 120 qualified for data extraction. 757 twin pregnancies were described. Most were treated with radiofrequency ablation (RFA) (n=363, 47.95%) and laser ablation (n=220, 29.06%). Statistically significant differences amongst the modalities were seen in technical success (p = 0.005), gestational age at presentation (p < 0.01), intervention (p = 0.01), and delivery (p = 0.01), respectively, and time between treatment and delivery (p < 0.01). Notably, pump twin survival did not differ based on treatment modality used (p = 0.196). Overall, complication rates were low with no differences in preterm premature rupture of membranes (PPROM) (p = 0.66), preterm labor (p = 0.58) or maternal hemorrhage between modalities (p = 0.28). Suture cord ligation, however, had a greater hemorrhage rate than RFA (p = 0.03). This embodies the first meta-analysis comparing treatment modalities for TRAP sequence with outcomes and complications. RFA is the most technically successful strategy. Prospective data is required to further understand the optimal modality and gestational age at treatment to ensure best overall outcomes. .

Slow molecular beams from a cryogenic buffer gas source

We study the properties of a cryogenic buffer gas source that uses a low-temperature two-stage buffer gas cell to produce very slow beams of ytterbium monofluoride molecules. The molecules are produced by laser ablation inside the cell and extracted into a beam by a flow of cold helium. We measure the flux and velocity distribution of the beam as a function of ablation energy, helium flow rate, cell temperature, and the size of the gap between the first and second stages of the cell. We also compare the velocity distributions from one-stage and two-stage cells. The one-stage cell emits a beam with a speed of about 82ms−1 and a translational temperature of 0.63 K. The slowest beams are obtained using the two-stage cell at the lowest achievable cell temperature of 1.8 K. This beam has a peak velocity of 56ms−1 and a flux of 9×109 ground-state molecules per steradian per pulse, with a substantial fraction at speeds below 40ms−1. These slow molecules can be decelerated further by radiation pressure slowing and then captured in a magneto-optical trap. Published by the American Physical Society 2024

Zelsuvmi: a promising treatment for molluscum contagiosum

Molluscum contagiosum (MC) is a common skin infection caused by a poxvirus, primarily affecting children and immunocompromised adults. It manifests as single or multiple raised, pearl-like papules and is highly contagious, spreading through skin contact or contaminated objects. Traditional treatments include cryosurgery, curettage, and pulsed dye laser ablation. However, in early 2024, berdazimer topical gel, 10.3% (ZELSUVMITM), was approved as the first topical treatment for MC. This review explores the potential of Zelsuvmi gel as a significant advancement in treatment due to its nitric oxide (NO)-producing properties. NO is a naturally occurring molecule in the body with multiple roles, including immune defense, antimicrobial activity, and modulation of apoptosis, inflammation, and cytokine production. The novel mechanism of action of Zelsuvmi, utilizing NO’s antiviral properties, has demonstrated compelling efficacy in clinical settings. The article also considers the broader implications of this treatment, not only for current dermatological practice but also for future research into innovative therapies for viral skin infections. Through an evaluation of clinical data, this review highlights Zelsuvmi’s potential to transform treatment approaches for MC, offering a non-invasive, effective option that may influence both clinical management and future prevention strategies.

Preparation and Characterisation of CdO@Au Nanoparticles by Hybrid System Using Laser Ablation and Plasma Jet Methods for Cytotoxicity Against Rat Embryonic Fibroblast Cell Line

The purpose of the research is to see if cadmium oxide@gold (CdO@Au) nanoparticles produced using the laser ablation and plasma jet method in deionised water (DW) solution could be a viable alternative to typical materials in cytotoxicity of rat embryonic fibroblast (REF) normal cell line. The cadmium nanoparticle core was prepared using a Q-switched Nd:YAG laser at a wavelength of 1,064 nm, with laser pulse energies varying between 800 mJ and 1,000 mJ over 500 shots. Gold nanoparticles shell prepared using atmospheric pressure plasma jet. The structural analysis process used X-ray diffraction (XRD) and UV-vis absorption spectroscopy to study the surface plasmon resonance (SPR) to follow the fast changes in the nanoparticles (NPs) colloidal solutions brought on by the interaction between Au sheets and CdO core. From UV-visible transmittance and absorbance spectra, it was observed that the transmittance pattern that can be obtained decreases. At the same time, the energy gap increases with the increase of laser energy, and this may be due to the increase in absorption. The XRD investigation revealed that the polycrystalline structure of CdO@Au NPs and their preferred orientation along (111) direction. The normal REF cell line was employed in the study to investigate the cytotoxicity of CdO@Au nanoparticles. After 48 h of exposure, the CdO@Au NPs displayed the maximum toxicity at a concentration of 100%.

Li diffusion in plagioclase crystals and glasses – implications for timescales of geological processes

Abstract. The growing interest in Li diffusion as a tool to determine timescales of short-time magmatic events, such as magma ascent during eruption, increases the necessity to better understand Li diffusion in common mineral phases. In this context, well-constrained diffusion coefficients and understanding of kinetic processes specific to mineral phases are of crucial importance. To gain further insight especially into the kinetic processes in plagioclase, we investigated the diffusion of Li between natural An61 plagioclase crystals and synthetic glasses of An80 plagioclase composition. Experiments were conducted at 200 MPa in rapid-heat/rapid-quench cold-seal pressure vessels (RH/RQ CSPVs) and internally heated pressure vessels (IHPVs) at temperatures between 606 and 1114 °C. Concentration and isotope profiles of Li were measured using femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry (fs-LA-MC-ICP-MS). We adopted a multispecies diffusion model and specified boundary conditions for plagioclase of labradoritic composition. Using this model, we were able to distinguish between an interstitial (DLii) and a vacancy process (DLiA), with the interstitial process being 0.2–1 orders of magnitude faster than the vacancy process, depending on temperature. DLii=10-3.76±0.58exp⁡-180.0±12.0kJmol-1RTm2s-1DLiA=10-5.53±0.16exp⁡-151.7±3.2kJmol-1RTm2s-1 Our data indicate charge compensation of Li by Na in both the crystal and the glass. Chemical Li diffusion coefficients in An80 glass are up to 3 orders of magnitude slower compared to Li tracer diffusion in silicate and aluminosilicate glasses and melts, which is attributed to slow Na diffusion at high An content. Our results for chemical diffusion of Li in plagioclase crystals are 1.5–2 orders of magnitude slower than Li tracer diffusion in An- and Ab-rich plagioclase determined in previous studies. This indicates that earlier studies on natural intermediate plagioclase compositions have underestimated timescales by up to 2 orders of magnitude. For accurate determination of timescales from Li diffusion in plagioclase we suggest further exploring the role of Na and a possible dependence on An content.

Self-assembly of MoTe2 nanostructures and nanocomposites over centimeter-large areas via femtosecond laser

The fabrication of patterned two-dimensional (2D) materials exhibits significant potential for advancing their electronic and optoelectronic applications. In this Letter, we demonstrate a rapid and scalable method for creating nanoscale periodic molybdenum ditelluride (MoTe2) nanostructures and mixed-dimensional heterostructures over a large area using direct femtosecond laser irradiation. Under intense femtosecond laser pulses, periodic energy deposition occurs in layered MoTe2 and subsequently induces the formation of MoTe2 periodic nanostructures. In addition, femtosecond laser ablation at a high repetition rate (1 MHz) results in the formation of numerous crystalline Te nanoparticles scattered on the surface of MoTe2 layers, creating mixed-dimensional Te/MoTe2 heterostructures. Notably, the fabrication of MoTe2 periodic nanostructures and mixed-dimensional heterostructures is driven by a self-assembled process. This technique enables the production of centimeter-scale MoTe2 periodic nanostructures and nanocomposites within 5 min, offering a cost-effective, lithography-free approach for fabricating periodically nanostructured 2D materials in large areas for practical applications in electronics, optoelectronics, catalysis, and sensing.

Protein misfolding by manganese (III) oxide nanoparticles generated by pulsed laser ablation in liquids

The high demand for metal oxide nanoparticles for applications in various fields has led to increased research and investigation. However, one tends to neglect the harmful effects of these synthesized nanoparticles on human health. Mn2O3 nanoparticles are a type of metal oxide nanoparticle that can have harmful effects if ingested or inhaled. In this study, Mn2O3 nanoparticles are synthesized using laser ablation at the manganese-water interface. The structural and optical properties of the nanoparticles are studied using HR-TEM, Micro-Raman, Ultraviolet–visible (UV–vis), and Photoluminescence spectroscopy. The cubic bixbyite α-Mn2O3 nanoparticles produced by laser ablation are used for studying their role in inhibiting or promoting protein fibrillation. Different concentrations of α-Mn2O3 nanoparticles are added to Human serum albumin (HSA) protein, where the fibrillation of the protein is investigated with the help of thioflavin T (ThT) dye using fluorescence spectroscopy. The protein misfolded on adding the nanoparticles that could be seen in the images obtained using fluorescence microscopic imaging, where the HSA forms a dense network of fibrils. In-vitro studies reveal that the increasing concentration of the nanoparticles increases the fibrillation of the HSA protein.