Multidisciplinary, Drug Discovery, Energy, Materials Science
42
Scopus Publications
Scopus Publications
Enhancing second harmonic generation-mediated photodynamic therapy via external electric field modulation Manu Kumar, Avinash Jukanti, Rivka Cahan, Dima Cheskis, Refael Minnes Plos One, 2026 Photodynamic therapy (PDT) utilizes light-activated photosensitizers (PS) to produce reactive oxygen species (ROS) for targeted bacterial destruction; however, its efficacy is often limited by inadequate light penetration, necessitating novel enhancements, such as the integration of second harmonic generation (SHG) through harmonic nanoparticles (HNPs) that convert two photons into one of higher frequency, thereby advancing the approach of SHG-based PDT for improved bacterial eradication. Our novel technique explores the impact of an e (EEF) on SHG intensity to augment PDT efficacy against Staphylococcus aureus ( S. aureus ). We investigated a novel conjugate, Bismuth Ferrite (BFO) in conjunction with protoporphyrin IX (PPIX), and compared it to the Barium Titanate (BT)-PPIX conjugate, under EEF of 0 V, 10 V, and 20 V for a duration of 5 minutes. The experiments utilized a near-infrared (NIR) femtosecond pulsed laser at 798 nm for excitation. Our findings show that EEF significantly enhances SHG intensity, improving photodynamic activity. Notably, BFO-PPIX conjugates significantly decreased bacterial survival to 35.8 ± 3.0% under EEF exposure, in contrast to 48.1 ± 3.2% without EEF. Similarly, to further substantiate the impact of EEF on SHG-based PDT efficacy, BT-PPIX conjugates resulted in bacterial survival of 57.1 ± 1.0% with EEF exposure, in contrast to 78.4 ± 3.7% without EEF. Our findings confirm the first study of EEF-modulated SHG in PDT, demonstrating its capacity to augment SHG intensity in HNPs-PPIX conjugates and improve therapeutic efficacy. These results highlight the potential of SHG-enhanced PDT, particularly with optimized EEF.
A laser-induced catalyst for the electrosynthesis of ammonia Divya Catherin Sesu, Hani Porat, Aneena Lal, Asmita Dutta, Manish Kumar Yadav, Refael Minnes, Arie Borenstein Nanoscale, 2026 Metal-embedded laser-induced graphene (LIG) enables efficient electrodes for electrocatalytic ammonia synthesis, a sustainable and cost-effective alternative to Haber–Bosch, operating under mild conditions with renewable electricity.
Tailoring PbTe quantum dot Size and morphology via ligand composition Svetlana Lyssenko, Michal Amar, Alina Sermiagin, Ayan Barbora, Refael Minnes Scientific Reports, 2025 The literature shows a lack of significant research on the synthesis of large spherical PbTe quantum dots (QDs), particularly with controllable sizes and morphology. Here, we present for the first time a novel hot-injection method for the tunable, high-quality synthesis of cubooctahedral PbTe QDs within the size range of 10 nm to 16 nm. This method employs a combination of oleic acid (OA) with shorter carboxylic acids, including octanoic (OctA), decanoic (DA), and lauric acids (LA), tested at various volumetric ratios. Our investigation reveals that different ratios of these acids result in diverse morphologies. Lower concentrations (0.5:5.5 and 1:5) favor cubical morphologies while increasing the concentration of short ligands induces a transformation to cubooctahedral shapes. This shape change is associated with the disruption of nanocrystal (NC) crystallinity. Higher ratios of short ligands produce PbTe NCs with a crystallite core and an amorphous shell. Our findings demonstrate the tunability and precise control achieved with this mixed capping ligand hot-injection method, which significantly impacts QD applications in photovoltaics, electronics, and energy. Notably, shorter capping ligand (OctA) result in more monodispersed PbTe QDs, yielding larger cubooctahedral QDs up to 16 nm. Conversely, using capping ligands with lengths similar to OA leads to unstable and less tunable synthesis.
One pot synthesis of klockmannite CuSe nanoparticles for supercapacitors and the electrolyte role Alina Sermiagin, Svetlana Lyssenko, Ayan Barbora, Hani Porat, Arie Borenstein, Refael Minnes Scientific Reports, 2025 In this paper, we successfully developed a rapid and straightforward one-pot synthesis method for klockmannite CuSe nanoparticles, demonstrating their potential application in supercapacitors. This synthesis is notably faster and simpler than previously reported methods, requiring no specialized equipment, and can be completed in just 30 min. This process consistently produces 2 nm CuSe nanoparticles with a well-defined hexagonal crystal structure, which is ideal for enhancing supercapacitor electrode performance. In our study, CuSe@SP (Copper selenide supported on SuperP carbon) electrodes exhibited optimal results in TBABF₄ electrolyte, achieving low resistance, high conductivity, and elevated energy density. Furthermore, our findings demonstrate that electrolyte properties-especially ion concentration and the size of negative anions-play a critical role in determining ion transfer rates, with smaller anions significantly enhancing performance. These results not only highlight the potential of our rapid synthesis method but also contribute to a deeper fundamental understanding of electrolyte behavior in advanced supercapacitor systems.
Tapering enhanced superradiance with a planar magnetic undulator L. Feigin, A. Gover, R. Minnes, A. Nause Physical Review Accelerators and Beams, 2025 Tapering enhanced superradiance (TES) is a novel radiation scheme that significantly improves the energy conversion efficiency in free-electron lasers. The undulator tapering design and optimization are crucial to the success of this efficiency boost and are fairly complicated tasks. Here, we demonstrate how to optimize the linear tapering rate using analytical magnetic field maps derived from pure permanent magnet (PPM) equations. A TES undulator (waveguided tapered undulator) is designed to operate at 0.5 THz at the zero-slippage regime, ensuring phase synchronicity and group velocity match between the electron beam and the radiation field. The superradiance condition is fulfilled by compressing the electron bunch to emit coherently. The results reveal a significant enhancement in energy conversion efficiency for both ideal and realistic beams. The real beam simulations use the ORGAD FEL parameters from the Schlesinger Accelerator Center at Ariel University. This work shows the potential of the TES method to achieve higher radiation energies through careful undulator design and optimized tapering and provides a complete model for this purpose.
A method for quantifying parallel growth between neuronal dendritic branches in vitro Inbar Dahari, Orly E. Weiss, Amos Ayubi, Danny Baranes, Refael Minnes Plos One, 2025 The morphology of dendritic trees critically shapes how neurons integrate and compute synaptic inputs. Dendritic morphogenesis results from the growth and spatial organization of branches, driven by intrinsic genetic programs, extrinsic environmental signals, activity-dependent processes, and spatial mechanisms such as tiling, avoidance, and overlap. Given their intricate architecture, particularly when branches overlap, developing methods to analyze and automate the quantification of this complexity is essential. Two-dimensional (2D) neuronal cultures provide a simplified framework for studying dendritic growth patterns but remain challenging to analyze due to network complexity, overlapping branches, and imaging limitations. Existing analysis tools often require substantial manual input or computational resources, limiting accessibility. We focused on measuring parallel growth between neighboring branches, a behavior frequently observed both in vivo and in culture. To address this challenge, we developed SOA.2.0 , a streamlined software platform for automated segmentation and orientation analysis of dendritic branches in 2D fluorescence images. SOA.2.0 improves the precision of morphological measurements, particularly branch parallelism, while remaining adaptable across diverse cellular and network models. Using SOA.2.0 , we quantified the extent of parallel growth among dendritic branches in cultured hippocampal neurons and compared these measurements with simulated random branch distributions. Our analysis revealed that parallel growth is a prevalent and non-random phenomenon, occurring among both sister and primarily non-sister branches of all generations, with frequencies significantly exceeding those observed in simulated random distributions. This behavior was frequently observed in relatively large groups of branches, sometimes up to eight, that extended for dozens of microns. Notably, this pattern was not detected in astrocytic processes within the culture. These results indicate that parallel branch growth is a prominent feature of dendritic architecture and may contribute to shaping the structural organization of neuronal networks, offering new insights into the mechanisms underlying their development and function.
Antibacterial property of lead telluride quantum dot layer fabricated on glass substrate Samuel Onuh Abuh, Svetlana Lyssenko, Ayan Barbora, Iryna Hovor, Faina Nakonechny, Refael Minnes Plos One, 2025 Lead Telluride (PbTe) is a narrow band gap semiconductor alloy with excellent thermoelectric properties for several energy harvesting applications. However, the antibacterial properties of PbTe quantum dots (QDs) have not been investigated. PbTe QDs were synthesized using simple spin-coating method and deposited on Titanium dioxide layered ITO glass substrates. The resulting layers of PbTe QDs on the substrates were characterized using high-resolution scanning electron microscope, energy-dispersive X-ray spectroscopy, Fourier transform infra-red spectroscopy and contact angle measurement. The characterization results showed thin layers of PbTe quantum dots with mean sizes 6.1 ± 0.5 nm, 9.8 ± 0.7 nm, and 13.2 ± 1.1 nm and reduced surface wettability. PbTe QDs were tested for their antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative Escherichia coli, Salmonella Paratyphi B and Pseudomonas aeruginosa. The antibacterial effect of the QDs was estimated using the zones of inhibition to bacterial growth. The results show excellent antibacterial activity of PbTe QDs towards Gram-negative bacteria. FTIR micro-spectroscopy suggests disruption of cell boundaries as possible mechanism of antibacterial action of PbTe QDs. Given the demonstrated antibacterial effectiveness, the PbTe QDs can be considered for nanocoating bacterial-prone surfaces like solar panels to minimize bacterial colonization and improve system performance.
Near-Infrared and Sono-Enhanced Photodynamic Therapy of Prostate Cancer Cells Using Phyto-Second Harmonic Generation Nanoconjugates Efrat Hochma, Michael A. Firer, Refael Minnes Polymers, 2025 This study investigates near-infrared (NIR)-induced, Phyto-enhanced, second harmonic generation-mediated photodynamic therapy (Phyto-SHG-PDT) using barium titanate (BT)/rhein/polyethylene glycol 100 (PEG100) and BT/Yemenite “Etrog” leaf extract/PEG100 nanoconjugates. We compare continuous-wave (CW), multi-line Argon-ion laser illumination in the NIR range with high-peak-power femtosecond (fs) 800 nm pulses. Under CW NIR light, BT/rhein nanoconjugates reduced PC3 prostate cancer cell viability by 18% versus non-irradiated controls (p < 0.05), while BT/extract nanoconjugates exhibited 15% dark toxicity. The observed SHG signal matched theoretical predictions and previous CW laser studies. Reactive Oxygen Species (ROS) scavenger 1,3-diphenyl-isobenzofuran (DPBF) showed reduced absorbance at 410 nm upon NIR illumination, indirectly supporting SHG emission at 400 nm from nanoconjugates. Under fs-pulsed laser exposure, pronounced two-photon absorption (TPA) and SHG effects were observed in both nanoconjugate types. Our results demonstrate the effectiveness of BT/rhein nanoconjugates under both laser conditions, while the BT/extract nanoconjugates benefited from high-power pulsed excitation. These results highlight the potential of BT-based Phyto-SHG-PDT nanoconjugates for NIR and blue light applications, leveraging nonlinear optical effects for advanced photochemical cancer therapies.
Carboxylic ligands and their influence on the structural properties of PbTe quantum dots Svetlana Lyssenko, Michal Amar, Alina Sermiagin, Refael Minnes Plos One, 2025 We present a low-cost, straightforward, and tunable hot-injection method for synthesizing PbTe quantum dots (QDs). By incorporating short-chain carboxylic acids—hexanoic acid (HexA), heptanoic acid (HepA), and acetic acid (AcA)—alongside oleic acid (OA), we controlled QD morphology and size within the range of 13–17 nm. The resulting QDs exhibited a well-defined cuboctahedral shape and a core-shell structure, consisting of a crystalline core and an amorphous shell. Morphology and growth behavior were strongly influenced by precursor composition, ligand ratio, and steric hindrance. Compared to QDs synthesized with longer-chain acids (lauric (LA), decanoic (DA), and octanoic acids(OctA)), which produced multiple shapes, the use of shorter ligands led exclusively to uniform cuboctahedral nanocrystals. PbTe QDs are typically reported as cubic when their size exceeds 10 nm. In contrast, our method consistently produces cuboctahedral structures in this size range. QDs were characterized by high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). These findings open a route toward controlled shape engineering of PbTe QDs for future applications in quantum optics, infrared detectors, and thermoelectrics.
2D nanocoin structure with binder-free CuS electrode for flexible symmetric solid-state supercapacitors Girish P. Patil, Chandradip D. Jadhav, Svetlana Lyssenko, Refael Minnes Electrochimica Acta, 2025 Copper-based chalcogenides are a popular choice for supercapacitor electrodes because of their unique electrochemical characteristics with ease of manufacture. We present a versatile, bendable solid-state device that incorporates a pliable polyvinyl alcohol (PVA) - Potassium hydroxide (KOH) membrane and copper sulphide (CuS) nanocoin electrodes on a stainless-steel current collector. One-pot colloidal synthesis is used to produce the CuS nanocoins, and a straightforward binder-free dip-and-dry technique is used to deposit them onto a flexible stainless-steel substrate. These nanocoins, with nanometric thickness (7.48 ± 1.49 nm) and lateral size (42.86 ± 1.14 nm), exhibit a highly crystalline structure with a promising electrochemically dynamic surface area of 551 m 2 /g that enhances charge storage, promoting pseudocapacitive behavior. This results in a high specific capacitance of 1159 F/g (811 mF/cm²) at a scan rate of 2 mV/s in a 1 M KOH electrolyte solution. Furthermore, we used the Trasatti approach to examine the different contributions that diffusion-limited and surface-controlled processes gave to the electrode's total charge storage capacity. We developed a flexible PVA-KOH membrane and employed it as a solid-state electrolyte to improve flexibility and device performance. This unique combination enables the flexible symmetric solid-state device to achieve an energy density of 11 Wh/kg and a power density of 900 W/kg, with a coulombic efficiency of 98 %. The device demonstrates remarkable long-term cyclic stability, retaining 89 % of its initial capacitance even after 10,000 charge-discharge cycles. The device's remarkable flexibility without performance loss further emphasizes its potential for energy storage and flexible electronics applications.
Screen Printing: An Ease Thin Film Technique Lakshmana Kumar Bommineedi, Nakul Upadhyay, Rafael Minnes Simple Chemical Methods for Thin Film Deposition Synthesis and Applications, 2023
