International Nano Letters is a peer-reviewed open access journal, covering fundamental and applied research in all disciplines of science, engineering and medicine. The overall aim of the International Nano Letters is to bring science and applications together on nanoscale and nanostructured materials with emphasis on synthesis, processing, characterization, and applications of materials containing true nanosize dimensions or nanostructures that enable novel/enhanced properties or functions. It is directed at both academic researchers and practicing engineers. This journal operates on an open access model and charges an Article Processing Charge (APC) to cover the costs of publication and ensure free and permanent access to published articles. We are committed to supporting researchers worldwide and offer APC waivers for authors from low- and middle-income countries, as well as in cases of financial hardship. Waiver requests are considered on a case-by-case basis and do not influence editorial decisions. For more information on APCs and waiver eligibility, please visit our APC & Waivers Policy page. Journal DOI: 10.57647/inl Journal Abbreviation: Int. Nano Lett. Journal Title Acronym: INL Journal Owner: Islamic Azad University Publisher: Islamic Azad University, Co-publishing, OICC Press, UK Managing Editor: Atefeh Ghaderi
Effect of Ni-Doping on the Structural and Optical Properties of ZnO Nanoparticles by Sol-Gel Method
In this study, the structure of zinc oxide doped with nickel at different concentrations of 0%, 1%, 3%, 5%, and 10% was examined. Zinc oxide was synthesized using the sol-gel method. Prepared sols coated on silicon wafer by spin coating method to be used as a photodiode in an electrical circuit for evaluation. XRD, UV-Vis, FT-IR, and SEManalyses were utilized to compare the structures of the solutions, powders and thin layers. The zinc oxide structure, with the addition of nickel, reduced in size from 28 nm to 21 nm. The substituted nickel created defects, which led to peak broadening of XRD and a blue shift in UV-Vis spectrum. The photovoltaic properties are studied to understand the behavior of the structures and the current-voltage diagrams of the samples were plotted. The calculations indicate that the zinc oxide sample doped with 3% nickel, prepared using this method, exhibits the best performance as an optical photodiode in the UV range. It shows a better response in I-C curve and ideality factor. Also, the structure of this percentage has the best performance.
Copyright (c) 2025 Elahe Moeini Sede, Mohammad Hossein Majles Ara, Seyedeh Soraya Mousavi, Fereshteh Rasouli Asl (Author) https://creativecommons.org/licenses/by/4.0
Selenium Chitosan and Selenium Carboxymethyl Chitosan Nanoparticles Combined with Curcumin Chitosan Nanoparticles to Enhance Antibacterial and Antiviral Activities
The use of nanoparticles is a promising strategy for combating pathogenic microorganisms. This study introduces a novel hybrid nanosystem combining selenium nanoparticles (Se NPs) with curcumin-loaded chitosan nanoparticles (Cur-CS NPs) to enhance antimicrobial efficacy. The results indicate that increasing the rotation speed to 1500 rpm, the potassium iodide and ascorbic acid concentrations to 40 mM and 70 mM, respectively, leads to the production of smaller Se NPs. Furthermore, Cur-CS NPs, prepared via ionotropic gelation, exhibited a pH-dependent release profile. Two hybrid systems were developed, one combining Se-chitosan NPs (Se-CS, 73 nm) with Cur-CS NPs, and another combining Se-carboxymethyl chitosan NPs (Se-CMCS, 80 nm) with Cur-CS NPs. Both combinations demonstrated remarkable broad-spectrum antibacterial activity, with similar minimum inhibitory concentrations (0.570–1.251 µg/mL) and minimum bactericidal concentrations against E. coli (1.251 µg/mL) and S. aureus (9.251 µg/mL). Furthermore, SeCS@Cur-CS NPs demonstrated potent antiviral activity, exhibiting a two-fold higher efficacy in inhibiting SARS-CoV-2 compared to SeCMCS@Cur-CS NPs. All systems maintained excellent biocompatibility, showing no cytotoxicity to Vero cells at concentrations up to 110 µg/mL. These findings suggest a synergistic effect between stabilized selenium nanoparticles and Cur-CS NPs, yielding a multifunctional platform with dual antibacterial and antiviral capabilities.
Copyright (c) 2025 Zahra Tavakoli, Reza Aalizadeh, Khosro Khajeh, Bijan Ranjbar (Author) https://creativecommons.org/licenses/by/4.0
Zinc- poly aniline- Palladium core shell for Non-enzymatic electrochemical detection of Acetaminophen
In this work, the electrochemical performance of ZnO-(3-Aminopropyl)triethoxysilane (APTES) was studied, along with poly(2-anilinoethanol)-(M-ZnO-P2AE NC) embedded with Pd nanoparticles for detecting Acetaminophen. The core-shell structure was synthesized in a three-step process: solvothermal synthesis, hydrothermal treatment, and surface decoration with Pd nanoparticles. Physicochemical analysis shows that Pd decoration enhances the optical and electrochemical performance of the composite, with high thermal stability. These results suggest that Pd nanoparticles alter the electronic structure of M-ZnO-P2AE NC, as confirmed by diffuse reflectance spectroscopy analysis. Electrochemical detection of Acetaminophen was conducted in the presence of other biomaterials to evaluate the selectivity of the electrode. The electrochemical analysis indicates that the prepared core-shell can effectively monitor Acetaminophen, with a detection limit of 10 nM.
Copyright (c) 2025 Mohammad Nikfarjam, Hamed Javadi, Javad Shabani Shayeh, Roya Sedghi (Author) https://creativecommons.org/licenses/by/4.0
Emerging Food Analytical Methods: Role of Nanotechnology
Food analysis is a crucial aspect of the food industry, ensuring the safety, quality, and authenticity of food products consumed by the public. To achieve this, various analytical methods are utilized, each with its own set of principles and applications. These methods play a vital role in detecting contaminants, ensuring compliance with regulations, and enhancing the overall quality of food products. The food industry is constantly evolving, and the demand for fast, accurate, and reliable analytical methods to ensure food safety, quality, and authenticity has never been greater. Traditional analytical methods have limitations such as low sensitivity, specificity, and throughput. Modern and emerging analytical techniques have been developed to overcome these limitations, providing faster, more accurate, and more comprehensive analysis of food samples. For instance, nanosensors, such as optical nanosensors for real-time detection of foodborne pathogens and toxins and nanoparticle-based multiplex nanosensors for identifying contaminants like mycotoxins and adulterants in complex food matrices, leverage nanotechnology to achieve ultra-sensitive, on-site monitoring in applications like smart packaging for spoilage prevention. Overall, food analytical methods are essential for maintaining the quality, safety, and authenticity of food products. By adhering to key principles e.g. accuracy, precision, selectivity, and sensitivity, these methods enable the food industry to meet regulatory requirements and consumer expectations. Accordingly, this review discusses the principles and applications of modern and emerging food analytical methods and techniques, with a central emphasis on the role of nanosensors in advancing food safety.
Copyright (c) 2025 Hamed Ahari, Sima Moradi, Kianoush Khosravi-Darani (Author) https://creativecommons.org/licenses/by/4.0
Synergistic Effect of Nano-TiO2 and CNTs on the Mechanical and Microstructural Properties of Cement–Silica Fume Stabilized Soils under Freeze–Thaw Cycles
Soft clay soils with high water content and low bearing capacity pose serious challenges for geotechnical infrastructures, particularly in cold regions where repeated freeze-thaw cycles accelerate structural degradation. Although various nano-additives have been utilized to enhance soil stabilization, the synergistic effect of nano titanium dioxide (nano-TiO2) and carbon nanotubes (CNTs) in cement–silica fume systems has not yet been systematically evaluated. In this study, the combined influence of nano-TiO2 and CNTs on the mechanical and durability properties of cement–silica fume stabilized soils was investigated through an extensive experimental program involving 243 specimens prepared with 12% cement and varying silica fume (5−20%), nano-TiO2 (1−5%), and CNT (0.15−0.45%) contents, cured for 7, 28, and 56 days. The specimens were subjected to 25 freeze–thaw cycles at a constant moisture content of 40%, exceeding the liquid limit of the soil.Results indicated that the silica fume–cement mixtures improved unconfined compressive strength (UCS) by an average of 85% compared to cement alone, while the incorporation of nano-TiO2 and CNTs further increased UCS by up to 142%. Water absorption decreased by approximately 85%, and strength loss under freeze–thaw cycles was minimal. These findings highlight the novelty and practical significance of the nano-TiO2–CNT composite in enhancing both the mechanical strength and frost durability of cement-stabilized soils, providing a sustainable approach to subgrade stabilization in cold climates.
Copyright (c) 2024 Hamed Ajorloo, S. Mohammad Mirhosseini, Emadaldin Hezavehi, Ali Hassani Joshaghani (Author) https://creativecommons.org/licenses/by/4.0
Nanotechnology-Enhanced Polymer Scaffolds with Antibacterial and Angiogenic Properties on Diabetic Wound Healing
Healing of wounds is a complicated and coordinated process with four phases, namely control of bleeding, inflammation, growth, and regeneration. Chemokines, growth inhibitors, and growth factors are all vital in establishing cell-cell contacts and the extracellular matrix. The conventional therapies include herbal treatments, specialist dressings, and interim scaffolds. Polymer scaffolds are a new innovation in wound treatment, providing a three-dimensional, temporary scaffolding for biological activities during healing. Objectives: A study attempted to speed wound healing processes by combining angiogenesis-stimulating protein (VEGF), vitamin D, silver carbon quantum dot (Ag-CQD), and henna extract (Lawsonia inermis) on polymeric nanostructures. Characteristics of the manufactured nanostructure investigated using scanning electron microscopy (SEM), Fourier-transform infrared attenuated total reflectance spectroscopy (FT-IR ATR), and X-ray Powder Diffraction (XRD). The release of Lawson and VEGF (Vascular endothelial growth factor) was measured using high-performance liquid chromatography (HPLC) and nanodrop micro-volume spectrophotometers. The nanostructures were further strengthened by immobilizing VEGF to increase angiogenesis at the wound site. Vitamin D and lawsone exhibited more than 70% favorable benefits on wound healing phases. Also silver nanoparticles demonstrate significant antibacterial activity against gram-positive and gram-negative bacteria. In terms of antibacterial efficacy, this scaffold was evaluated against Staphylococcus aureus and Escherichia coli, and the scaffold Gel/Chi/Pcl/AgCQD/Law/VEGF with 175−200 nm fibers and 10 mg of Lawson was shown to be stable at pH =7.4. Thus, the produced scaffold exhibited considerable resistance against S. aureus, and chitosan mixed with Lawson material appeared to be extremely promising in wound healing.
Copyright (c) 2024 Hayder Sudan Abbas Obaid, Fateme Mirzajani, Amin Hamidi, Iliya Fattahiyan, Meysam Omidi (Author) https://creativecommons.org/licenses/by/4.0
Isotherm Investigation and Assessment of the Adsorption Efficacy of Zinc Ions on Natural Zeolite and Zeolite Modified with Anionic (SDS) and Cationic (CTAB) Surfactants
This investigation examines the efficacy of natural clinoptilolite zeolite and its modified variants, utilizing the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) and the anionic surfactant sodium dodecyl sulfate (SDS), for the removal of zinc ions from aqueous solutions. Solutions containing zinc at varying concentrations were formulated, and the residual ion concentrations post-adsorption were assessed utilizing atomic absorption spectroscopy. The findings demonstrate that surface modification with anionic SDS surfactant dramatically enhances adsorption performance, achieving an exceptional capacity of 18.56 mg/g at 200 mg/L initial concentration. This represents a substantial threefold enhancement compared to natural zeolite (5.57 mg/g) and a notable fivefold superiority over CTAB-modified zeolite (3.85 mg/g), highlighting the crucial influence of surfactant charge characteristics. The adsorption isotherm analyses suggested that the adsorption process conformed to a monolayer model. Nonlinear regression analysis of the empirical data against various isotherm models indicated that the Fritz-Schlunder model offered the most accurate representation for the natural zeolite, while the Weber-van Vliet model exhibited optimal conformity for both surfactant-modified systems. In summary, the results of this study indicate that the modification of clinoptilolite zeolite with the anionic surfactant SDS constitutes a promising approach for augmenting the efficiency of zinc ion removal from aqueous systems.
Copyright (c) 2024 Rashid Zandlashani, Abbas Kasaei (Author) https://creativecommons.org/licenses/by/4.0
The Effect of Applied Electric Field on Hydrogen Incorporation During the Formation of Au Nanoparticles Fabricated by Laser Ablation
In the present study, gold nanoparticles (NPs) were fabricated by pulsed laser ablation (PLA) method in distilled water environment under different external electric field strengths. The effect of the electric field on the characteristics of produced NPs was traced through X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) and transmission electron microscopy (TEM). Optical properties were studied by UV-visible spectroscopy. The XRD results showed an orthorhombic lattice, alongside the typical cubic structure of Au, which was attributed to the hydrogen incorporation in the crystalline structure of Au nanoparticles. The interaction between hydrogen and gold did not vary linearly with the increased of applied electric field. At an electric field of 20 V/cm, this interaction was almost negligible. Furthermore, the peak observed at around 2000 cm−1 in the FT-IR spectrum provided additional evidence for possible Au-H interactions. Based on the TEM images, some non-spherical shapes such as nanorods were successfully synthesized under higher electric field strengths. Moreover, the interaction between hydrogen and gold likely induced a slight blue shift in the UV-Vis spectrum. The formation of Au hydride makes our sample a promising candidate for use as anoptical hydrogen sensor; however, further research is needed.
Copyright (c) 2025 Parisa Ojaroody, Mohammadreza Hantehzadeh, Elham Darabi (Author) https://creativecommons.org/licenses/by/4.0
Water Chemical Treatment by Photocatalytic Activity of Graphene Oxide–Decorated Titanium Dioxide/Ag Nanocomposite
In the present study, gold nanoparticles (NPs) were fabricated by pulsed laser ablation (PLA) method in distilled water environment under different external electric field strengths. The effect of the electric field on the characteristics of produced NPs was traced through X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) and transmission electron microscopy (TEM). Optical properties were studied by UV-visible spectroscopy. The XRD results showed an orthorhombic lattice, alongside the typical cubic structure of Au, which was attributed to the hydrogen incorporation in the crystalline structure of Au nanoparticles. The interaction between hydrogen and gold did not vary linearly with the increased of applied electric field. At an electric field of 20 V/cm, this interaction was almost negligible. Furthermore, the peak observed at around 2000 cm−1 in the FT-IR spectrum provided additional evidence for possible Au-H interactions. Based on the TEM images, some non-spherical shapes such as nanorods were successfully synthesized under higher electric field strengths. Moreover, the interaction between hydrogen and gold likely induced a slight blue shift in the UV-Vis spectrum. The formation of Au hydride makes our sample a promising candidate for use as an optical hydrogen sensor; however, further research is needed.
Copyright (c) 2025 Pegah Mosayebi, Davoud Dorranian, Kourosh Behzad, Amir Hossein Sari (Author) https://creativecommons.org/licenses/by/4.0
Multilayer Propylenidene for Optoelectronic Applications: A First-Principles Study of Electronic and Optical Characteristics
This study investigates a novel two-dimensional carbon allotrope, propylenidene (PPD). The electronic and optical properties of monolayer, bilayer, and trilayer configurations of PPD were explored using den sity functional theory (DFT). The results reveal metallic behavior in all layered forms, accompanied by highly anisotropic optical responses. Notably, the in-plane polarization of incident light induces strong optical absorption, high dielectric constants, and exceptional optical conductivity. The layers also exhibit significant transparency due to high transmission coefficients. Furthermore, these properties exhibit clear layered-dependent tuning. The findings facilitate the rational design of carbon-based materials with tailored optical properties, paving the way for high-efficiency optoelectronic devices and emerging electro-optical technologies.
Copyright (c) 2025 Roya Majidi, Hamid Eftekhari, Ahmad. I. Ayesh (Author) https://creativecommons.org/licenses/by/4.0
Designing and Optimizing Bioactive Bone Dressing for Tooth Socket Preservation and Regenerative Dentistry Application: In Vitro Study
To address the challenge of preserving sufficient alveolar bone volume and quality following tooth extraction, this in vitro study presents the design and optimization of a bioactive scaffold composed of carboxymethyl cellulose (CMC), alginate (Alg), and tricalcium phosphate (TCP). This composite aims to facilitate post extraction socket healing and promote osteogenesis. The scaffold was fabricated using freeze-drying to achieve a porous, sponge-like structure. Sodium alginate and CMC were mixed at a 30:70 ratio, with TCP incorporated at 3% wt% and crosslinked using a 0.5 M calcium chloride solution. The formulation was subjected to controlled freezing and lyophilization steps to enhance porosity and mechanical integrity. Characterization studies confirmed a highly porous structure (79% porosity) with interconnected pores, as visualized by SEM. Mechanical testing revealed improved compressive strength due to TCP incorporation, while FTIR and XRDanalyses confirmed polymer bonding and the presence of TCP, respectively. Degradation testing showed a slow initial breakdown followed by accelerated degradation, leading to complete scaffold resorption by day 28. Biological assays, including MTT, Alizarin Red staining, and ALP activity, demonstrated the scaffold’s excellent biocompatibility and ability to support cell proliferation, migration, and enhanced calcium deposition. These findings suggest that the scaffold has potential for promoting osteogenesis in vitro, warranting further investigation for its possible application in alveolar bone regeneration.
Copyright (c) 2025 Elahe Houshmand, Sadaf Javadpour, Mohammadhossein Ehsani, Mike Sabeti, Javad Mehrani Sabet, Seyyed Behnam Abdollahi Boraei, Sattar Yousef, Behzad Houshmand (Author) https://creativecommons.org/licenses/by/4.0
Nanocatalysis and Nanosensors: Trends and Prospects
In recent years, there has been a growing interest in nanoparticles for preparing nanocatalysts used in the catalysis of many important industrial reactions. Indeed, nanotechnology provides a promising strategy for developing green nanocatalysts which are known as environment-friendly catalysts promoting the different chemical reactions. On the other hand, Nanosensors are some nanostructured materials capable of sensing (1) environmental alterations like temperature, pressure, and pH, (2) different kinds of toxins or pollutions in soils, air, and water, and (3) biochemical and metabolic changes inside cells. Therefore, nanosensors can be applicable for detecting physical and chemical factors in a variety of areas including the food industry, environmental issues (detecting pollutions), medicine (clinical diagnosis applications), biological research, and military (antiterrorism applications). Nowadays, nanomaterials are widely used for developing nanosensors, which include carbon nanotubes, polymers, metals, metal oxides, thin films, and graphene. While previous reviews have often addressed nanocatalysis or nanosensors in isolation, they rarely integrate both fields or emphasize their shared nanomaterials and applications in sustainable contexts, such as green chemistry and food safety. This chapter fills these gaps by providing a comprehensive overview of nanocatalysts and nanosensors, their current applications in various areas (with a focus on the food industry for pathogen detection, biofuel production, and preservation), and future perspectives, including emerging trends in biodegradable and recyclable nanomaterials. By bridging these domains, this review offers unique insights into interdisciplinary advancements that promote eco-friendly innovations and address challenges in scalability and toxicity. A notable portion of the review specifically highlights applications in the food industry, including pathogen detection, biofuel production, and food preservation. While previous literature may discuss these applications, this review ties together the roles of both nanocatalysts and nanosensors within this essential sector, providing insights that may have been overlooked in earlier studies. This review stands out due to its integrative approach, deep focus on sustainability and food applications, insights into regulatory environments, and critical evaluation of the potential risks associated with nanomaterials, making it a timely and relevant contribution to the field of nanotechnology.
Copyright (c) 2024 Hamed Ahari, Tugba Ozdal, Kianoush Khosravi-Darani, Sima Moradi (Author) https://creativecommons.org/licenses/by/4.0
Zinc oxide nanoparticles assembling by a green chemistry method
Zinc oxide is a semiconductor material with an interesting potential for photocatalysis of organic pollutants. It has been prepared according an eco-friendly green method, using five various plant extracts (banana, rosemary, bitter orange, olive tree, comfrey). Two different synthesis processes were tested: a hotplate synthesis and a hydrothermal method. Metal precursor used was zinc acetate. Plants present in the process allowed the formation and the self-assembling of ZnO during the crystal growth thanks to the large chemical family of polyphenol which act as reductants. Crystalline and organic matter-free compounds obtained after annealing were characterized with diffractive reflectance spectroscopy (DRS) to determine gap energies and confirm ZnO belonging to semiconductors, X-ray diffraction to verify the crystalline structure and its features, Fourier transform infrared spectroscopy (FTIR) to check the characteristic functional group and scanning electron microscopy (SEM) to reveal the self-assembling forms of ZnO. Data about the shapes, dimensions and crystal planes of zinc oxide were regarded in the light of the plant and the synthesis method used. This work has highlighted the morphologies of ZnO obtained on the basis of the synthesis method and the plant extracts. Highlight Zinc oxide has been synthesized by a green process using several plant extracts. Hotplate and hydrothermal synthesis methods were compared in terms of ZnO properties. SEM observations of the various ZnO powders obtained showed great variations in morphologies. The ZnO variabilities obtained were the result of the plant used rather than the synthesis method used. XRD and gap energy measured are quite similar whatever the plant extract.
Copyright (c) 2025 Adrien Bonneau, Marie-Angèle Frémy, Sylvie Villain, Gilles Baratto, Patricia Merdy (Author) https://creativecommons.org/licenses/by/4.0
PMMA/TiO₂ Nanocomposite Derived Selective Surface Coatings for Improved Optical Properties with Cold Plasma Assisted
Progressive evolution of nanostructured coatings with costume-made structural and optical properties is of major interest for different high-tech applications. This work targeted the incorporation of titanium dioxide (TiO₂) nanoparticles to poly(methyl methacrylate) (PMMA) nanocomposite films across three concentrations (1%, 2%, and 3%) using the casting method. These films were later treated with cold dielectric barrier discharge (DBD) plasma to refine their structure and optical properties. Investigations were systematically studied through the work including the extinction coefficient, absorption coefficient, dielectric constant (real and imaginary), energy gap, Urbach energy, and refractive index. A significant increase resulted in the real dielectric constant, refractive index, and absorption coefficient, on the other hand, a decrease due to strong absorption was noted in the imaginary dielectric constant and extinction factor. Direct and indirect energy gap ranged from 4.7 to 4.5 eV, and 3.4 to 3.25 eV, respectively. Urbach energy data elevated from 366 to 395 meV, which suggests improved charge carrier transport attributed to structural modifications achieved by plasma induction. Also, cold DBD plasma treatment efficiently increased the roughness of the surface, and as a result, improved the film's optical absorption abilities. These findings were confirmed using structural analysis, X-ray diffraction (XRD) showed a mixture of semi-crystalline and amorphous phases. SEM examined revealed a uniform TiO₂ distribution across the PMMA accompanied by gaining a roughened morphology. AFM analysis also showed a boost in surface roughness from 0.828 to 3.04 nm after incorporating TiO₂ and applying plasma treatment. These results propose that PMMA/TiO₂ nanocomposite films showed encouraging potential for applications in fiber optics, optical sensors, photocatalysis, and light-emitting diodes (LEDs). Highlights · The study targeted the incorporation of titanium dioxide (TiO₂) nanoparticles into poly(methyl methacrylate) (PMMA) nanocomposite films across three concentrations (1%, 2%, and 3%) using the casting method. · The investigations were systematically studied through the work, including the optical properties and Urbach energy. · The direct and indirect energy gap decreased from 4.7 to 4.5 eV, and from 3.4 to 3.25 eV, respectively. Urbach energy data elevated from 366 to 395 meV, suggesting an improvement in charge carrier transport due to structural modifications achieved by plasma induction. · The SEM examination revealed a uniform TiO₂ distribution across the PMMA accompanied by a roughened morphology. AFM analysis also showed a boost in surface roughness from 0.828 to 3.04 nm after incorporating TiO₂ and applying plasma treatment. · The innovative results of PMMA/TiO₂ nanocomposite films showed encouraging potential for applications in fiber optics, optical sensors, photocatalysis, and light-emitting diodes (LEDs).
Copyright (c) 2025 Rasheed N. Abed, Hassan Hashim, Muataz Ali, Roaa T. Abdulla, Ali B. M. Ali, Mohammed Al-Baidhani, Kadhim A. Aadim, Abdulrahman H. Shaker, Khalid Zainulabdeen, Ahmed A. Alamiery, Muna S. Bufaroosha, Emad Yousif (Author) https://creativecommons.org/licenses/by/4.0
Insight mechanistic of metal nanoparticle–microbe Interactions: A Review
The modern era has accepted the significance of nanomaterials and their exploitation for the advancement of several disciplines. In view of the increasing applications and demand of nanomaterials, numerous techniques for the synthesis of nanoparticles (NPs) mediated by several means have been discovered, synthesis mediated by microorganisms being one of the most feasible ones. NPs have emerged as efficient drug carriers and as potential antimicrobials against existing diseases as a result of their interactions with microorganisms. The antimicrobial effect of biosynthetic NPs is contributed by the action of reactive oxygen species augmented by the capping agents that get adhered to the surface of NPs during the biosynthesis process. The present review discusses the use of various microorganisms for the biosynthesis of metal NPs through varied mechanisms that take place when microbes interact with aqueous solutions of metals. Furthermore, it aims to address the mechanistic insight into the metal nanoparticle-microbe interactions as potential antimicrobials. At the same time, it demonstrates the necessity of adopting a multidisciplinary approach for the exploitation of microbe-nanoparticle interactions in diverse plant species against a plethora of microbes affecting them. Highlights · The review emphasizes the use of microorganisms to synthesize metal nanoparticles in a sustainable and cost-effective manner. This approach serves as an environmentally friendly alternative to traditional chemical synthesis methods, reducing ecological harm and resource use. · It provides in-depth insights into the enzymatic processes driving nanoparticle formation, particularly highlighting the role of nitrate reductase. This enzyme facilitates the reduction of metal ions into nanoparticles, offering a clearer understanding of the biosynthesis mechanisms. · The manuscript showcases the potent antimicrobial properties of these biosynthesized nanoparticles. They are effective against a wide range of plant pathogens, including bacteria, fungi, and viruses, making them valuable for plant disease management. · It discusses the need to investigate less phytotoxic metal nanoparticles, such as those made from zinc or iron. This shift aims to address environmental and safety concerns associated with the more commonly used silver nanoparticles, which can pose toxicity risks. The review advocates for a collaborative framework that integrates nanotechnology, microbiology, and plant science. This multidisciplinary approach is essential to fully understand and harness the potential of nanoparticle-microbe interactions
Copyright (c) 2025 Amardeep Singh, Namita Basnal, Swati Singh, Shailendra Singh Gaurav, Dharmendra Pratap, Gyanika Shukla (Author) https://creativecommons.org/licenses/by/4.0
Geometrical parameters measurement of surface functionalized micromachined micro-cantilever using optical method
Abstract Micro-cantilever arrays with different dimensions are fabricated by micromachining technique onto silicon <1 0 0> substrate. These sputtered gold-coated micro-cantilevers were later surface-functionalized. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical diffraction with laser source are employed to characterize the morphology and image measurement of the micro-cantilever arrays, respectively. The spatial resolution produced in the proposed image measurement method is approaching 1 μm, and the repeatable precision is confirmable in nanometers. Compared with conventional AFM and SEM measurement techniques, the proposed method has demonstrated sufficient flexibility, repeatability, and reliability. The experimental results have been analyzed and presented in this paper for MEMS micro-cantilevers. The scanning white light interferometry-based, two-point high-resolution optical method is presented for characterizing micro-cantilevers and other MEMS microstructures. In this piece of work, we investigate the microstructure fabrication and image measurement of geometrical parameters such as length, width, and step height of micro-cantilevers fabricated using bulk micromachining technique onto silicon <100> substrate.
Unsteady MHD free convection boundary-layer flow of a nanofluid along a stretching sheet with thermal radiation and viscous dissipation effects
Abstract In this work, we study the unsteady free convection boundary-layer flow of a nanofluid along a stretching sheet with thermal radiation in the presence of magnetic field. To obtain non-similar equations, continuity, momentum, energy, and concentration equations have been non-dimensionalized by usual transformation. The non-similar solutions are considered here which depend on the magnetic parameter M , radiation parameter R , Prandtl number P r , Eckert number E c , Lewis number L e , Brownian motion parameter N b , thermophoresis parameter N t , and Grashof number G r . The obtained equations have been solved by an explicit finite difference method with stability and convergence analysis. The velocity, temperature, and concentration profiles are discussed for different time steps and for the different values of the parameters of physical and engineering interest.
Improved antimycobacterial activity of rifampin using solid lipid nanoparticles
Abstract Rifampin (RIF) is one of the front-line drugs in therapy of tuberculosis (TB). The emergence of multidrug-resistant strains of mycobacteria has greatly contributed to the increased incidence of TB. Nano-based formulation of several antimicrobials has been shown to improve either antibacterial efficacy or pharmacokinetic behavior. In this study, RIF-loaded solid lipid nanoparticles (SLNs) were prepared by a modified microemulsion-based method and their particle size, zeta potential, encapsulation efficiency, morphology, and antibacterial activity against Mycobacterium fortuitum were evaluated. The resulting SLNs were spherical with diameter of about 100 nm, with low negative zeta potential, and an encapsulation efficiency of 82%. The formulation also sustained the drug release for 72 h. The antimycobacterial efficacy was greatly improved against M. fortuitum , and the minimum inhibitory concentration of drug-loaded SLNs was eight times less than free RIF. Drug-free SLNs and the ingredients showed no antibacterial effect. It can be concluded that as expected, solid lipid nanoparticles are promising vehicles for enhanced antimycobacterial effect of rifampin.
Designed plasmonic nanocatalysts for the reduction of eosin Y: absorption and fluorescence study
Abstract In this work, we report a one-step green synthesis of gold nanoparticles (AuNPs) by microwave irradiation using nontoxic and biodegradable polysaccharide chitosan as a reducing and stabilizing agent. The interaction between gold nanoparticles with the amine group of chitosan was confirmed by Fourier transform infrared spectroscopy analysis, and the stability of the nanoparticle is ascertained by zeta potential measurements. Transmission electron microscopy photograph and dynamic light scattering measurements confirmed the average size of gold nanoparticles as 25 nm. The ability of the synthesised gold nanoparticles as a catalyst for the reduction of eosin dye in the presence of NaBH 4 was monitored by means of spectrofluorometry and spectrophotometry. It is found that the NaBH 4 -induced reduction of eosin is enhanced in the presence of AuNPs even without a catalyst. Time-resolved fluorescence decay studies also confirmed the reduction of eosin in the presence of AuNPs.
Hydrothermal synthesis, characterization, and investigation of optical properties of Sb3+-doped lithium silicates nanoparticles
Abstract The hydrothermal synthesis and optical properties of undoped and Sb 3+ -doped lithium metasilicate and lithium disilicate nanomaterials were investigated. The microstructures and morphologies of the synthesized Li 2−2 x Sb 2 x SiO 3 and Li 2−2 x Sb 2 x Si 2 O 5 nanoparticles were studied with powder X-ray diffraction and scanning electron microscopy techniques, respectively. The synthesized undoped and doped lithium metasilicate and lithium disilicate nanomaterials, respectively, are isostructural with the standard bulk Li 2 SiO 3 (space group Cmc2 1 ) and Li 2 Si 2 O 5 (space group Ccc2) materials. The electronic absorption and photoluminescence spectra of the synthesized materials are studied. The measured optical properties show dependence on the dopant amounts in the structure.
A 12-bit, low-voltage, nanoampere-based, ultralow-power, ultralow-glitch current-steering DAC for HDTV
Abstract In this paper, a novel 12-bit current-steering binary-weighted digital-to-analog converter (DAC) based on nanoampere bits is designed and modified for high-definition television (HDTV) applications. As a part of a widely used consumer appliance, it is aimed to be such designed to consume power as low as possible. Hence, as a distinguished idea, prime concentration is focused on the reduction of the currents providing the bits of the proposed DAC. To do this, current mirrors operating in the weak inversion region are arranged to establish the least significant bit (LSB) current as low as 10 nA while the power supply is also reduced to 1 V, resulting to an ultralow power of 52.9 μW. Many other powerful ideas are then deliberately combined to maintain both high speed and very low glitches required for HDTV application despite those ultralow currents and power. The result is a speed of 100 MS/s, an ultralow glitch of ≃10.91 fAs, |INL| ≤ 0.988 LSB, |DNL| ≤ 0.99 LSB, and a spurious-free dynamic range of ≃73 dB. These results caused the proposed DAC to execute a distinguished overall performance (defined as figure of merit) greatly better than some other advanced ones by outstanding ratios of 77 to 277,185. Hspice simulations with the SMIC 0.18-μm complementary metal-oxide semiconductor technology have been used to validate the proposed circuit. Performance evaluation of the proposed DAC versus Monte Carlo simulations and also a wide range of temperature variations proved both its well mismatch insensitivity and thermal stability.
Thin film optical BTB pH sensors using sol–gel method in presence of surfactants
Abstract Bromothymol blue (BTB) thin films were prepared by depositing a thin layer of a solution containing tetraorthosilicate and BTB pH indicator in the presence of surfactants, namely cetyltrimethylammonium bromide (C 19 H 42 BrN, CTAB) or dodecyldimethylamine oxide (C 14 H 31 NO, 69%), C 16 H 35 NO (11%), Genaminox LA onto a glass slide substrate. CTAB or GLA surfactants were used to improve the mesostructure of the host material and to increase its porosity. Optical BTB thin films were found to be sensitive against pH and behave as free BTB. This provides evidence for weak interactions between the BTB molecules and the host silica matrix. The effects of the sol mixture on the stability and reproducibility and the colorimetric response to solutions of different pH were examined and pKa values were determined. The BTB thin film sensors showed an advantage over the encapsulated monolithic sensors in which the thin film sensors exhibit a faster response time than the monolithic disks. These pH sensors showed reproducibility and high stability behavior.
Prevention of weld-decay in austenitic stainless steel by using surface mechanical attrition treatment
Abstract Surface mechanical attrition treatment (SMAT) was applied to the samples of a type AISI 304 stainless steel in order to induce grain refinement as well as formation of twins. Transmission electron microscopy and X-ray diffraction analysis results showed that the average grain size at the surface of the SMATed sample was about 10 nm. The untreated and SMATed samples were then welded using a one-pass gas tungsten arc procedure. The heat-affected zone (HAZ) of the samples was examined by optical microscopy and corrosion tests. Results of the double loop electrochemical potentiokinetic reactivation tests showed that the degree of sensitization in the HAZ for the SMATed sample was very low as compared to that of the untreated one. The pre-SMATed sample was resistant to intergranular corrosion. This is mainly due to the formation of high density of twins which are not prone to carbide precipitation because of their regular and coherent atomic structure and extreme low grain boundary energy as compared with those of other grain boundaries.
Retracted: Electrical conductivity of hydrogenated armchair nanoribbon as a gas sensor using non-equilibrium Green's function method
Retraction This article was mistakenly published twice. For this reason this duplicate article has now been retracted. For citation purposes please cite the original: http://www.inljournal.com/?_action=articleInfo&article=16 Abstract Nanosensing properties of hydrogenated edge armchair graphene nanoribbons (HAGNR) are investigated. Using non-equilibrium Green's function method in the tight-binding approach, the effects of hydrogen and oxygen adsorption on current–voltage ( I - V ) characteristics and also the electrical conductivity of these systems are calculated. We found that the I - V curves of these systems change by the adsorption of hydrogen or oxygen molecules. Also, we found that conductivity of these systems at low adsorption concentrations increases, while at high adsorption, concentrations decrease. This could be explained in terms of semiconducting or metallic properties of the adsorbed system which was obtained from electronic properties of our clean HAGNR system. On the other hand, the local density of states of some sites has a metallic behavior, and that of other sites has a semiconducting behavior. Note that our results are investigated at a fixed temperature T = 300 K, i.e., room temperature. By calibrating conductivity in terms of adsorbed gas molecules, one can make a gas nanosensor
Characterization of catalytic chemical vapor-deposited SiCN thin film coatings
Abstract Silicon carbonitride thin films of 480 to 730-nm thicknesses were grown on silicon substrate using ammonia and hexamethyldisilazane gas sources using catalytic chemical vapor deposition process. Compositions of silicon, carbon and nitrogen in the SiCN films were varied by changing the flow rate of ammonia gas. The effect of deposition conditions on the structural, optical and mechanical properties of SiCN thin films was examined. X-ray photoelectron spectroscopy analysis indicated that the higher flow rate of ammonia gas results in higher nitrogen and lower carbon content in the deposited thin films. The measurement of stress as a function of substrate temperature in the SiCN film showed that the stress changes from compressive to tensile in the range of 275°C to 325°C. With these preliminary characterization tests, it is expected that SiCN nano-thin films can be used for developing sensors for harsh environment.
Graphene wrapped BiVO4 photocatalyst and its enhanced performance under visible light irradiation
Abstract Graphene wrapped BiVO 4 (GW-BiVO 4 ) photocatalyst is successfully synthesized via facile sol–gel method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The morphology of GW-BiVO 4 looks like a human embryo embedded inside the amniotic sac. The photocatalytic performance of GW-BiVO 4 for the decolorization of methylene blue is investigated. GW-BiVO 4 system reveals enhanced photocatalytic activity for degradation of methylene blue in water under visible light irradiation as compare to pure BiVO 4 catalyst and BiVO 4 decorated on graphene sheet (GD-BiVO 4 ). The experimental result shows that the wrapping of the graphene sheets in this composite catalyst enhances the photocatalytic performance under visible light. This enhance activity is mainly attributed to the effective quenching of the photogenerated electron–hole pairs which confirmed by photoluminescence spectra. Trapping experiments of radicals and holes were performed to detect the reactive species generated in the photocatalytic system, experimental results found that the direct hole oxidation reaction is obviously dominant during the photocatalytic reactions on the GW-BiVO 4 system.
Preparation and characterization of SnO2 nanoparticles by hydrothermal route
Abstract This paper demonstrates the synthesis of SnO 2 nanoparticles using a simple hydrothermal route in the presence of the surfactant hydrazine at 100 °C for 12 h. X-ray diffraction (XRD), field emission scanning electron microscopy, and transmission electron microscopy (TEM) were employed to characterize the as-prepared product, and optical property was studied by UV-visible diffuse reflectance spectroscopy (DRS). The XRD pattern of the as-prepared sample is indexed to the tetragonal structure of SnO 2 , and the calculated particle size is 22.4 nm, which is further confirmed by TEM. The selected area electron diffraction patterns showed continuous ring patterns without any additional diffraction spots and rings of secondary phases, revealing their crystalline structure. Analysis of the DRS spectrum showed the bandgap of the synthesized SnO 2 to be 3.6 eV. The anionic surfactant hydrazine plays a key role in the formation of the SnO 2 nanostructures. A probable reaction for the formation of SnO 2 nanoparticles is proposed.
Retracted: Optimization of radiation modes in asymmetric planar slab optical waveguides
Retraction This article was mistakenly published twice. For this reason this duplicate article has now been retracted. For citation purposes please cite the original: http://www.inljournal.com/?_action=articleInfo&article=17 Abstract In this paper, we try to optimize the substrate-radiation/substrate-cladding (cover) radiation modes in terms of their performance parameters. It is well known that the guided modes can only be normalized. However, the radiation modes can also be normalized using the delta/Dirac function. We try to optimize the waveguide design parameters for the known cases to achieve performance as good as guided modes. The formal electromagnetic theory is applied to study the radiation modes. The normalization condition on radiation mode has been carefully used during analysis. The results are found to be satisfactory. It has been concluded that we can modify the performance of radiation modes according to our requirements. The performance is compared with the guided mode. The paper discusses guidelines to optimize the radiation modes for various constraints.
Tailored hybrid hyperbranched polyglycidol-silica nanocomposites with high third-order nonlinearity
Abstract One of the most convenient techniques for optical material fabrication is the sol–gel processing. It can be performed at low temperature that enables one to entrap even relatively unstable organic substances into silica matrix at the nanometer scale, thus developing homogeneous hybrid organic–inorganic nanocomposite materials of various functionalities. Here, novel hybrid organic–inorganic nanocomposites with good optical transparency and high third-order nonlinearity were prepared biomimetically through the mineralization of dendritic macromolecules (hyperbranched polyglycidols) using a compatible ethylene glycol-containing silica precursor. The synthesis was performed at neutral pH media in aqueous solutions without addition of organic solvents at ambient conditions owing to the catalysis of processing. Polyglycidols provided also the formation of gold nanoparticles localized in their core. They served as reducing and stabilizing agents. It is shown that trace amounts of nanoparticles could regulate nonlinear properties of a nanocomposite. High nonlinearity manifests itself in a supercontinuum generation at remarkably short lengths ca. 1 mm. The phenomenon consists of filamentous intense white lighting due to the spectral broadening of initial ultrashort (femtosecond) laser pulses propagating through the material. The developed hybrid nanocomposites possessing large nonlinearity, high-speed optical response, stability under intense lighting, low-cost, and easy preparation are promising for a diverse range of applications as active components for all-optical signal processing from chemical sensing to biological cell imaging and lighting control in telecommunication.
Preparation of nanostructured TiO2-based photocatalyst by controlling the calcining temperature and pH
Abstract Nanostructured TiO 2 has been synthesized using one-step sol–gel method and characterized by different characterization techniques (SEM, EDS, XRD, and UV–vis spectroscopy). The photocatalytic degradation of methylene blue (MB) and Congo red (CR) is studied with the synthesized TiO 2 . The photocatalytic degradation data has been validated using several kinetic models. The TiO 2 showed efficient photocatalytic degradation performance on MB and CR. In addition to this, the effect of pH on the photocatalytic degradation has been investigated. The TiO 2 showed enhanced photocatalytic performance in basic media than that in neutral or acidic ones.