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This study investigates the fabrication of large-area, highly-ordered monolayers of PbTe quantum dots (QDs) on TiO2/ITO substrate, using a fast, simple, and repeatable spin-coating technique. For the first time, a real monolayer (a layer with the height of a single QD) covering approximately 3 cm2 was successfully prepared, achieving a root-mean-square roughness (Rq) of 1.37 nm. The research systematically explores key parameters such as QD morphology, concentration, spin-coating conditions, substrate characteristics, wetting properties, and solvent effects to optimize thin film deposition. The findings reveal that the spin-coating method favors the formation of layers with spherical QDs (6-9 nm) over cubical QDs (10-13 nm). The findings highlight the significant influence of solvent evaporation rate, viscosity, and wettability on monolayer quality. Chloroform was identified as the optimal solvent for cubical QDs (~90% coverage), while hexane was more effective for spherical QDs (90%-100% coverage). Beyond monolayers, high-quality bilayers were also fabricated, demonstrating the method's potential for multilayer fabrication. This rapid and efficient method for monolayer and bilayer fabrication marks a significant breakthrough in producing uniform, large-area films, facilitating seamless integration with existing technologies. It offers a scalable and cost-effective solution, opening the door to broader applications in fields that demand high-quality thin film deposition., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Lyssenko et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Photodynamic therapy can be significantly improved by techniques utilizing light windows of higher tissue penetration depths with optimally matched photoactive agents to provide deep interstitial treatment. Classical blue light photosensitizers were photodynamically activated using infrared light via coupled harmonic nanoparticles with optimized intermediary distances using spacers. Upon 800 nm pulsed laser irradiation perovskite nanoparticles with optimized coupling to either curcumin or protoporphyrin IX reduced the viability of MCF7 breast cancer cells by 73 percent and 64 percent, respectively, while exhibiting negligible dark toxicity. The findings pave the way for clinical adaptation of ease-of-synthesis photodynamically active preparations operable under deep tissue penetrating infrared lights using commonly available otherwise infrared inactive classical blue light photosensitizers., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Refael Minnes has patent NEAR-INFRARED PHOTODYNAMIC THERAPY USING SECOND HARMONIC GENERATION NANOPARTICLE AND VISIBLE LIGHT REACTIVE PHOTOSENSITIZER pending to Refael Minnes and Ayan Barbora]., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Combination of photosensitizers (PS) with nanotechnology can improve the therapeutic efficiency of clinical Photodynamic Therapy (PDT) by converting visible light reactive PSs into Near-Infrared (NIR) light responsive molecules using Harmonic Nanoparticles (HNP). To test the PDT efficiency of HNP-PS conjugates, pathogenic S. aureus cell cultures were treated with perovskite (Barium Titanate) Second Harmonic Generation (SHG) nanoparticles conjugated to photosensitizers (PS) (we compared both FDA approved Protoporphyrin IX and Curcumin) and subjected to a femtosecond pulsed Near-Infrared (NIR) laser (800 nm, 232-228 mW, 12-15 fs pulse width at repetition rate of 76.9 MHz) for 10 minutes each. NIR PDT using Barium Titanate (BT) conjugated with Protoporphyrin IX as HNP-PS conjugate reduced the viability of S. aureus cells by 77.3 ± 9.7% while BT conjugated with Curcumin did not elicit any significant effect. Conventional PSs reactive only to visible spectrum light coupled with SHG nanoparticles enables the use of higher tissue penetrating NIR light to generate an efficient photodynamic effect, thereby overcoming low light penetration and tissue specificity of conventional visible light PDT treatments., Competing Interests: The authors have declared that no competing interests exist.