Sotirios Baskoutas

Tetrahedral III–V semiconductor quantum dots (QDs) have recently emerged as promising cadmium-free nanomaterials for optoelectronic, quantum-photonic, and bioimaging applications. However, despite rapid progress in their synthesis, the intrinsic many-body excitonic properties that govern their optical response remain largely unexplored. In this work we employ an atomistic empirical pseudopotential and screened configuration-interaction (EPM–SCI) framework to investigate the electronic structure, optical absorption, and multiparticle states of ideally passivated tetrahedral InAs and InP quantum dots (QDs) with edge lengths ranging from 2 to 14 nm. The calculated single-exciton transition energies of tetrahedral InP QDs agree closely with available experimental data, whereas the InAs results are consistent with our benchmark TDDFT calculations and reproduce the established size dependence of spherical InAs QDs. At equivalent edge lengths, the exciton binding energy remains larger in InP than in InAs. Biexcitons remain bound throughout the investigated size range, with binding energies of approximately 5–30 meV. Within the ideal-passivation and dielectric-screening model employed here, positive trions remain bound in both materials, whereas negative trions are bound in InAs but antibound in InP. Our results establish a theoretical benchmark for interpreting future experiments and provide fundamental design principles for tetrahedral III–V quantum dots for advanced optoelectronic and quantum-photonic applications.

Computational Materials Science is one of the most important tools that have contributed to the huge developments in modern Nanotechnology

Chlorpyrifos (CP) belongs to organophosphate pesticide group. It is extensively applied in agricultural and household settings due to its broad-spectrum insecticidal properties. However, its persistence, bioaccumulative behavior, and toxicological effects on non-target organisms, including humans, pose significant environmental and public health concerns. CP and its metabolites, particularly two including 3,5,6-trichloropyridinol (TCP) and chlorpyrifos-oxon (CPO), have been recently reported to be widely found various samples such as in soils, sediments, water bodies, crops, and even human biological fluids. These compounds disrupt biogeochemical cycles, alter soil microbial communities, inhibit enzyme activities, and are linked to neurotoxicity, endocrine disruption, and genotoxic effects. Conventional remediation strategies such as photodegradation, ultrasonication, and filtration remain ineffective due to incomplete degradation and secondary pollution risks. Recent studies highlight the efficiency of microbial degradation, especially by bacteria such as Bacillus, Klebsiella, Pseudomonas and Enterobacter as a promising, eco-friendly alternative. These microorganisms utilize CP as a only carbon source, and degradation calibre is greatly governed by various abiotic factors like pH, temperature, and moisture. The genetic as well as enzymatic analyses reveal key roles of organophosphorus hydrolases encoded by genes such as opd and mpd. The integration of plant growth-promoting traits and laccase activity further enhances their bioremediation capability. Additionally, recent advancements in biosensing techniques for CP detection offer improved sensitivity and real-time monitoring. This review provides a comprehensive analysis of CP’s environmental fate, toxicological impact, degradation pathways, and the emerging role of bacterial bioremediation, highlighting its potential for sustainable environmental detoxification.

1. Sulfonylureas herbicides act by targeting acetolactate synthase (ALS), a crucial enzyme involved in the production of branched-chain amino acids necessary for plant development.[1,2] One such he...

Hexavalent chromium [Cr (VI)] is a prevalent and highly toxic environmental contaminant known for its persistence and severe ecological and health consequences. Its high solubility and mobility contribute to long-lasting pollution, while its carcinogenic properties pose significant risks to living organisms. Conventional physicochemical methods such as precipitation, ion exchange, and membrane filtration are employed for Cr (VI) removal but often suffer from drawbacks including high costs, incomplete elimination, and generation of secondary pollutants. In contrast, microbial and biotechnological methods offer sustainable, environmentally friendly alternatives for detoxifying Cr (VI). This review focuses on microbial remediation strategies, including biosorption, bioaccumulation, biotransformation, and bioleaching, with particular attention to the roles of bacteria and fungi. Key factors discussed include microbial resistance genes and enzymatic systems that facilitate the reduction of Cr (VI) to the less harmful Cr (III). Advances in designing microbial consortia, understanding genetic regulation, and integrating bioprocess engineering are also explored to enhance remediation efficacy. Comparing traditional and biological approaches highlights the superior sustainability and scalability of microbial systems for large-scale environmental treatment. Innovations in microbial bioremediation through biotechnological approaches present a promising path forward for mitigating chromium pollution and restoring environmental health in contaminated ecosystems.

Colloidal quantum dot (QD) solid-state films are fundamental building blocks for modern optoelectronic devices. In these films, the complex dielectric environment formed by surrounding QDs and organic ligands significantly modifies their electronic and excitonic properties, posing a considerable theoretical challenge. Herein, we report a robust first-principles scheme capable of accurately predicting the fundamental and optical gaps of these films. The methodology’s success is rooted in a twofold innovation: the development of optimized, dimensionally consistent Gaussian basis sets that accurately treat both extended and confined systems, and a unique density functional parameterization. This parameterization employs screened range-separated hybrid density functional theory, uniquely incorporating the QD size-dependence of the range-separation parameter while introducing the solid-state film’s scalar dielectric constant. This comprehensive scheme determines the electronic structure with an accuracy competing with state-of-the-art self-consistent GW calculations. Applying it to group IV and II–VI QD solid-state films, we achieve an excellent reproduction of experimental fundamental and optical gaps, allowing the accurate determination of the exciton binding energy. We established that this binding energy in solid-state films scales linearly with the inverse QD diameter, a key relationship predicted by classical electrostatics that is largely independent of the material type. Conventional hybrid functional calculations are found to severely fail to quantify this energy and its size-dependent scaling relations. This work provides a cost-effective and broadly applicable theoretical framework for accurately determining the electronic and optical properties of colloidal QD solid-state films.

Supercapacitors have emerged as a critical energy storage technology due to their exceptional power density, rapid charge–discharge kinetics, and long cycle life. Despite their advantages, enhancing their energy density remains a key challenge for broader applications in electric vehicles, renewable energy integration, and portable electronics. This study presents a novel electrolyte formulation comprising nickel chloride (NiCl ₂ ) in ethyl alcohol and cobalt nitrate (Co(NO ₃ ) ₂ ) in acetone, designed to improve the electrochemical performance of supercapacitors. The proposed electrolytes exhibit remarkable enhancements in specific capacitance, with NiCl ₂ ‐based systems achieving 123 F/g with TiO ₂ nanoparticles and 138.5 F/g with CuO nanoparticles, while Co(NO ₃ ) ₂ ‐based systems demonstrate 127 F/g and 131 F/g, respectively. Furthermore, the specific energy (SE) reaches 76.2 Wh/kg and 67.2 Wh/kg for NiCl ₂ electrolytes, and 70 Wh/kg and 72.5 Wh/kg for Co(NO ₃ ) ₂ electrolytes, highlighting their potential for high‐energy storage applications. These findings suggest that the integration of transition metal salts in organic solvents can significantly boost supercapacitor performance by optimizing ion transport and redox activity. The study underscores the importance of advanced electrolyte engineering in overcoming existing limitations in energy storage systems.

Drug resistance in microorganisms is a growing global threat, highlighting the urgent need for novel therapeutic agents. This study evaluates the antibacterial and anti-SARS-CoV potential of fungal endophytes isolated from A. marmelos . Among 16 endophytes screened, the ethyl acetate extract of the #3 AMLBF strain ( Fusarium vanettenii ) exhibited the strongest antibacterial activity against several pathogens. This extract showed minimum inhibitory concentrations (MICs) ranging from 0.49 to 0.8 µg/ml. GC/MS analysis of the active extract identified 45 compounds. Furthermore, molecular docking against the SARS-CoV-2 spike glycoprotein revealed nine potential ligands, with Anthraergosta-5,7,9,22-tetren-3-ol p -chlorobenzoate showing the most potent binding affinity (− 10.2 kcal/mol), a value exceeding that of the standard chloroquine (− 6.5 kcal/mol). These results indicate that the organic extract from this fungal strain is a promising candidate for the discovery of new antimicrobial agents. Graphical abstract