Physical properties,biological applications and biocompatibility studies on biosynthesized single phase cobalt oxide (Co3O4) nanoparticles via Sageretia thea (Osbeck.)

Cobalt oxide nanoparticles were successfully biosynthesized by complete green process using aqueous leaf extracts of Sageretia thea as chelating agent. Diverse techniques were applied for characterization. Antibacterial (with and without UV illumination), antileishmanial, antioxidant and enzyme inhibition applications were assessed, while freshly isolated macrophages and red blood cells were used for biocompatibility studies. Good antibacterial nature and enhancement of bactericidal nature upon UV modulation is reported. Staphylococcus aureus and Escherichia coli are indicated as most susceptible bacterial strains. Significant cytotoxic potential is revealed with IC₅₀ calculated as 12.82 µg/ml and 3.16 µg/ml against the axenic leishmanial promastigote and amastigote cultures respectively. Biogenic cobalt oxide nanoparticles indicated DPPH free radical scavenging potential, while moderate antioxidant capacity and reducing power was demonstrated. Bioinspired cobalt oxide also demonstrated alpha amylase and protein kinase inhibition at higher concentrations. Biogenic cobalt oxide was found as more cytotoxic to macrophages (IC₅₀ = 58.55 µg/ml) then to RBC’s (IC₅₀ >200 µg/ml). Our results indicate green synthesis as an alternative, effective and eco-friendly method for the biosynthesis of cobalt oxide nanoparticles with numerous biological applications.     

Bioinspired and green synthesis of nanoparticles from plant extracts with antiviral and antimicrobial properties: A critical review

Currently green synthesis of nanoparticles has attained much interest because of their safe nature, environmentally benign, ease in manufacturing, and low production cost. It is a reliable process for developing a wide array of nanostructures such as metal salts from plants/fungal/bacterial extract and hybrid materials. Green synthesis of nanoparticles provided promising and sustainable alternative approach to conventional synthesis approaches. Recent studies demonstrated that nanoparticles are highly promising for antiviral and antimicrobial properties. Here in, the advancement in green synthesis of nanoparticles using natural compounds such as plant extracts, fruit juices and other relevant sources have been highlighted. A deep insight into antiviral and antimicrobial activities of these nanoparticles provided. These nanoparticles offer diverse opportunity to counter life threating viral and other antimicrobial infections. This review offers understanding of the recent data that provide the readers various strategies to design and develop advance nanomaterials via greener approach. Current challenges, critical overview and future outlook of the green synthesis of nanoparticles and possibilities of their effective and exotic exploration for antimicrobial and antiviral applications are summarized.     

Synthesis,characterization and impregnation of lead sulphide semiconductor nanoparticles on polymer matrix

Lead sulphide nanoparticles were prepared using a precursor and dual sources methods. The composites were fabricated by stabilizing chemically synthesized semiconductor PbS nanocrystals into laurylmethacrylate and ethyleneglycol dimethacrylate matrix in the presence of tri-n-octylphosphine. PbS nanocrystals were dispersed in toluene as a compatible medium for the polymerization and cross-linking of poly laurylmethacrylate networks. The nano-sized particles and polymer composites were characterized by XRD and TEM. Possible formulations and incorporation of these PbS nanoparticles in polymer matrix have been discussed. The reported lead sulphide nanoparticles into tailered polymeric system show greater uniformity and stability.     

Hydrothermal synthesis of precursors of neodymium oxide nanoparticles

The nanometric precursors of neodymium oxide of various morphologies were prepared via a hydrothermal reaction route. The precursors and their thermal evolution to neodymium oxide phase were characterised by means of X-ray diffraction (XRD), transmission electron microscopy (TEM, HRTEM), thermal analysis (TG, DTA, EGA-MS), FTIR and atomic force microscopy (AFM). It was found that the reaction conditions (temperature, pressure) played a key role for the product formation of desired morphology and structure. At mild conditions (140 °C) precursor with unusual fibrous morphology and Nd(OH)_2.45(Ac)_0.550.45H₂O stoichiometry was obtained. Upon heating this phase transformed, via intermediate cubic oxide, into trigonal Nd₂O₃ at 800 °C. Nd(OH)₃ hydroxide obtained at severe conditions (180 °C) transformed upon heating into cubic Nd₂O₃ phase at about 500 °C and this phase was stabilised even at 800 °C. The fibrous precursors appeared to be a convenient material for preparation of homogeneous thin coatings on planar substrates is shown.     

Honey-mediated synthesis of Cr2O3 nanoparticles and their potent anti-bacterial,anti-oxidant and anti-inflammatory activities

Green synthesis of nanoparticles has gained tremendous attention in recent era which is pertinent to their unique properties and broad applications. This approach is cost-effective, environment-friendly as well as highly biocompatible. In this research, chromium oxide nanoparticles (Cr₂O₃-NPs) were synthesized by using Apis mellifera honey as a reducing and capping agent and their anti-bacterial, anti-biofilm, anti-oxidant and anti-inflammatory abilities were explored. Ultra Violet-visible double beam spectroscopy revealed that chromium underwent d-d transition during synthesis of nanoparticles. X-ray diffraction (XRD) analysis verified that Cr₂O₃-NPs were crystalline in nature and average crystal size was 24 nm. Energy-dispersive X-ray (EDX) analysis confirmed that chromium and oxygen formed nano-composites in solution which possessed a stable form. Scanning electron microscopy (SEM) provided morphological characteristics of nanoparticles and proved that their average size was 20 nm. Cr₂O₃-NPs displayed excellent anti-bacterial activity (minimum inhibition zone, 20 mm; maximum inhibition zone, 26 mm) against 30 selected clinical isolates of Klebsiella pneumoniae as determined by agar well-diffusion method. Their antibacterial activity was considerably superior to that of three selected antibiotics including Gentamicin, Ciprofloxacin and Cefepime. However, no synergism was observed between nanoparticles and these antibiotics as calculated from fractional inhibitory concentration index (FICI) values all of which were  > 1. The synthesized nanoparticles possessed good biofilm inhibition potential (60 % to 73 %) at all concentrations (20 µg/ml to 50 µg/ml) tested. Cr₂O₃-NPs exhibited excellent anti-oxidant activity (IC₅₀ = 128 µg/ml) which was nearly equivalent to that of ascorbic acid. Anti-inflammatory effect of Cr₂O₃-NPs was also significant (IC₅₀ = 549 µg/ml) and comparable to that of standard. Both anti-oxidant and anti-inflammatory capacities were found to increase with an increase in the concentration of Cr₂O₃-NPs. In conclusion, this work revealed that Apis mellifera honey-mediated synthesis of Cr₂O₃-NPs could be investigated for future biomedical applications.     

β-Functionalized ethylchalcogenolate complexes of lead(II): Synthesis, structures and their conversion into lead chalcogenide nanoparticles

The reactions of Pb(OAc)₂·3H₂O with NaER yield homoleptic colorless to yellow complexes of composition, [Pb(ER)₂] (ER = SCH₂CH₂NMe₂ (1), SeCH₂CH₂NMe₂ (2) and SeCH₂CH₂COOMe (3)). These complexes were characterized by elemental analyses, UV–Vis and ¹H NMR data. Molecular structures of [Pb(ECH₂CH₂NMe₂)₂] (E = S or Se) have been established by single crystal X-ray diffraction analyses. These molecules have a distorted trigonal bipyramidal configuration around lead with the nitrogen atoms of the chelating chalcogenolate ligands occupying the axial positions. Thermal behavior of these complexes was studied by TG analysis. Pyrolysis in a furnace or in HDA (hexadecylamine) gave PbE nanoparticles which were characterized by UV–Vis, photoluminescence, XRD, EDAX, and TEM measurements.     

Surfactant-free synthesis of sub-stoichiometry tungsten oxide nanoparticles and their use as anode buffer layers in organic solar cells

A surfactant-free synthesis of small-sized tungsten trioxide is presented. Nanoparticles with an average size of 4.6 ± 1.5 nm are prepared via hot-injection techniques in ethanol. Due to the reducing properties of ethanol, a sub-stoichiometry composition WO_3-x (x∼0.4) is obtained. The partial reduction of W^+VI to W^+V becomes visible in the bluish color of suspensions and powder samples and in optical spectroscopy (UV-Vis). The nanoparticles are further characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDXS) and infrared spectroscopy (FT-IR). Due to their small size, their high colloidal stability and the absence of surfactants, layers from the as-prepared WO_3-x nanoparticles are ideally suited to form anode buffer layers in organic solar cells. Exemplary solar cells show good power conversion efficiency of 6.3%.     

Biosynthesis of metal and metal oxide nanoparticles using various parts of plants for antibacterial,antifungal and anticancer activity: A review

The synthesis of several metal oxide nanoparticles mediated by microbes and plants and their different bio-applications gain more attention from the research community in the biomedical science field. As concerned with plants, which comprise plenty of biofunctional compounds like alkaloids, steroids, tannins, nutritionals, and flavonoids. As reported plant-mediated biogenic fabrication of the metal oxide nanoparticles at an eco-friendly, less hazardous, and low cost is a convincing way, further, it is treated for biological screening in terms of applications like antifungal, cytotoxicity, antibacterial, and anti-plasmodia activity. These dose-dependent activities and the morphology (shape, size) also impact the efficiency of the bio-inspired NPs. The eco-friendly way of using plant material highlights their non-hazardous nature, cost-ineffective, and facile which is an alternative to synthesizing chemically. Plants rich in metabolites or chemicals may act as reducing and capping agents during the synthesis of NPs. The present review reveals a plant-mediated synthesis of metal and metal oxide NPs, their morphological analysis like shape and size, crystalline nature using several techniques, and their biological applications.     

Synthesis and characterization of gallium oxide nanoparticles

This review is based on the literature describing several methods for the synthesis of gallium oxide nanoparticles. Several techniques have been used for the synthesis of gallium oxide Ga₂O₃ nanoparticles. Gallium oxide Ga₂O₃ nanoparticles have been synthesized from different precursors. Different synthetic methods and different precursors produce nanoparticles which vary in size and shape. Over a dozen of synthetic methods for preparation of gallium oxide Ga₂O₃ nanoparticles together with the characterization techniques used have been discussed.     

Insights into the synthesis and mechanism of green synthesized antimicrobial nanoparticles,answer to the multidrug resistance

Emergence of the multidrug resistant human pathogenic strains is posing a serious health challenge. Resistant strains carry mutations which help them to resist conventional drugs. Therefore, it is required to produce more effective agents that are able to degrade the resistant pathogenic bacterial strains. The antimicrobial properties of nanoparticles (NPs) by eco-friendly green synthetic methods have pulled attention everywhere owing to their exceptional properties and small particle size of 100 nm. NPs are considered to belong to a group of antimicrobial agents which have ability to go inside microbial cells and kill them. In this comprehensive review, we are discussing the green synthetic methods used for the synthesis of NPs targeting the microbes. Additionally, several characterization techniques of antimicrobial NPs are also discussed. Subsequently, various methods used for the analysis of antimicrobial activities and their mechanisms are also examined.     

First synthesis and in vitro biological assessment of isosideroxylin, 6, 8-dimethylgenistein and their analogues as nitric oxide production inhibition agents

A modular and efficient synthesis of the biologically significant C-methylisoflavones isosideroxylin(1),6,8-dimethylgenistein(2) and their analogues(3-8) is established for the first time.The synthesis is realized in 7-8 steps in overall yields of 16%-24%from commercially inexpensive phloroglucinol and features a high yielding Vilsmeier-Haack reaction,Friedel-Crafts acylation,Gammill's protocol and Suzuki coupling as the pivotal transformations.Next,these compounds evaluated for their inhibitory potency on the production of nitric oxide(NO) in lipopolysaccharide(LPS)-activated RAW-264.7 cells as an indicator of anti-inflammatory activity.The results showed that all the compounds decreased NO production in a dose-dependent manner without marked cytotoxicity and IC_(50) values are found in the range of 10.17-33.88 μmol/L.Of note,compounds 3 followed by 1,7 and 8 show comparable inhibitory activity with positive control(N-monomethyl-L-arginine,L-NMMA).     

Antibacterial study of Eucalyptus grandis fabricated zinc oxide and magnesium doped zinc oxide nanoparticles and its characterization

Mg-doped zinc oxide and zinc oxide nanoparticles were prepared by using methanolic seed extract from the Eucalyptus grandis plant via a green approach. Phytoconstituents present in seed extract act as capping and stabilizing agents for the biosynthesis of nanoparticles. Doping of Mg to zinc oxide nanoparticles increases the bandgap energy, thus enhancing its chemical, physical and optical properties. Further, it was characterized by various techniques such as scanning electron microscopy giving morphological information about the wurtzite hexagonal structure of bio-synthesized nanoparticles. X-ray diffraction technique tells about the crystalline nature of particles and the average crystallite size for zinc oxide and doped zinc oxide nanoparticles. Mg as a dopant enhances the properties of nanoparticles, thus making it more efficiently applicable as an antibacterial agent against Escherichia coli, gram-negative bacteria.     

Zinc oxide nanoparticles synthesized using Oldenlandia Umbellata leaf extract and their photocatalytic and biological characteristics

The aim of this study was to examine the environmentally friendly green production of zinc oxide nanoparticles (ZnO NPs) utilizing Oldenlandia Umbellata (OU) leaves extract, as well as to study the photo catalytic and biological activities of these particles. XRD, UV-Visible, FT-IR, SEM, EDAX, TEM and Zeta potential studies were used to investigate the purity and properties of as synthesized ZnO NPs. From the FT-IR investigations presenting functional groups were verified. The hexagonal form and wurtzite crystal nature were confirmed by SEM and XRD photographs. The decreasing zeta potential of ?23.7 mV suggested the stability of OU-ZnO NPs, which was validated by Zeta potential and EDAX measurements. The OU-ZnO NPs' photo catalytic activity was also examined using their methylene red dye degradation potential. It also has a DPPH test that revealed it had a 66% radical scavenging activity. Furthermore, this substance was proven to be an effective anti-fungal agent against Candida albicans, which demonstrated a maximum mycelial inhibition of 12.5 ± 0.7. Additionally, the biosynthesized nanoparticles had high antibacterial activity verses all of the microbiological strains tested to varying degrees.     

Durian waste mediated green synthesis of zinc oxide nanoparticles and evaluation of their antibacterial,antioxidant, cytotoxicity and photocatalytic activity

ABSTRACT

The synthesized ZnO NPs using durian rind in solution has shown maximum absorption at 355.5?nm with the bandgap of 3.33?eV, spectrophotometrically. SEM and TEM studies revealed that the shape of the synthesized ZnO NPs was spherical with an average size of 280 and 283?nm, respectively. However, DLS analysis of ZnO NPs revealed the average particle size of 456?d.nm. The presence of [100], [002], [101], [102], [110], [103], [200], [112] and [201] planes in XRD corroborate the formation of pure wurtzite structure of ZnO NPs. Synthesized ZnO NPs showed remarkable photocatalytic activity on degradation of methylene blue and sulfanilamide, antioxidant activity, considerable antimicrobial activity against Escherichia coli and Staphylococcus aureus, and considerable cytotoxic activity against brine shrimp. The sulfanilamide degradation was found to be 96.70%, under natural sunlight and in the presence of 0.1% ZnO NPs at pH 10 with a time of 3?h. The dye degradation was found to be 84% under sunlight in the presence of 0.01% ZnO NPs at pH 10 with a time of 40?min. The synthesized ZnO NPs may be explored furthermore in the fields of wastewater treatment, biomedicine, biosensor, and nanotechnology.     

Preparation and properties of amorphous titania-coated zinc oxide nanoparticles

Amorphous TiO₂-coated ZnO nanoparticles were prepared by the solvothermal synthesis of ZnO nanoparticles in ethanol and the followed by sol-gel coating of TiO₂ nanolayer. The analyses of X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that the resultant ZnO nanoparticles were hexagonal with a wurtzite structure and a mean diameter of about 60 nm. Also, after TiO₂ coating, the TEM images clearly indicated the darker ZnO nanoparticles being surrounded by the lighter amorphous TiO₂ layers. The zeta potential analysis revealed the pH dependence of zeta potentials for ZnO nanoparticles shifted completely to that for TiO₂ nanoparticles after TiO₂ coating, confirming the formation of core-shell structure and suggesting the coating of TiO₂ was achieved via the adhesion of the hydrolyzed species Ti-O⁻ to the positively charged surface of ZnO nanoparticles. Furthermore, the analyses of Fourier transform infrared (FTIR) and Raman spectra were also conducted to confirm that amorphous TiO₂ were indeed coated on the surface of ZnO nanoparticles. In addition, the analyses of ultraviolet-visible (UV-VIS) and photoluminescence (PL) spectra revealed that the absorbance of amorphous TiO₂-coated ZnO nanoparticles at 375 nm gradually decreased with an increase in the Ti/Zn molar ratio and the time for TiO₂ coating, and the emission intensity of ZnO cores could be significantly enhanced by the amorphous TiO₂ shell.     

Green synthesis and chemical characterization of copper nanoparticles using Allium saralicum leaves and assessment of their cytotoxicity,antioxidant, antimicrobial,and cutaneous wound healing properties

In recent decades, nanotechnology is growing rapidly owing to its widespread application in science and industry. The aim of the experiment was the green synthesis of copper nanoparticles using Allium saralicum R.M. Fritsch aqueous extract and assessment of their cytotoxicity, antioxidant, antibacterial, antifungal, and cutaneous wound healing effects under in vitro and in vivo conditions. These nanoparticles were characterized by Fourier transformed infrared spectroscopy (FT‐IR), UV–visible spectroscopy, field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). DPPH free radical scavenging test was done to assess the antioxidant properties, which indicated similar antioxidant potentials for CuNPs@Allium and butylated hydroxytoluene. Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), and Minimum Fungicidal Concentration (MFC) were specified by macro‐broth dilution assay. CuNPs@Allium indicated higher antibacterial and antifungal effects than all standard antibiotics (p ≤ 0.01). Also, CuNPs@Allium inhibited the growth of all bacteria at 1–8 mg/ml concentrations and removed them at 2–8 mg/ml concentrations (p ≤ 0.01). In the case of antifungal properties of CuNPs@Allium, they prevented the growth of all fungi at 1–4 mg/ml concentrations and destroyed them at 2–8 mg/ml concentrations (p ≤ 0.01). In vivo experiment, after creating the cutaneous wound, the rats were randomly divided into six groups (n = 10): untreated control, treatment with Eucerin basal ointment, treatment with 3% tetracycline ointment, treatment with 0.2% CuSO₄ ointment, treatment with 0.2% A. saralicum ointment, and treatment with 0.2% CuNPs@Allium ointment. Use of CuNPs@Allium ointment in the treatment groups substantially reduced (p ≤ 0.01) the wound area, total cells, neutrophil, macrophage, and lymphocyte and remarkably raised (p ≤ 0.01) the wound contracture, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate compared to other groups. The synthesized CuNPs@Allium had high cell viability dose‐dependently (Investigating the effect of the plant on HUVEC cell line) and revealed this method was nontoxic. The results revealed the useful non‐cytotoxic, antioxidant, antibacterial, antifungal, and cutaneous wound healing effects of CuNPs@Allium.     

Nonaqueous synthesis of metal oxide nanoparticles:Review and indium oxide as case study for the dependence of particle morphology on precursors and solvents

Nonaqueous solution routes to metal oxide nanoparticles are a valuable alternative to the well-known aqueous sol-gel processes, offering advantages such as high crystallinity at low temperatures, robust synthesis parameters and ability to control the crystal growth without the use of surfactants. In the first part of the review, we give an overview of the various nonaqueous routes to metal oxides, their surface functionalization and their assembly into well-defined nanostructures. However, we will strongly focus on surfactant-free processes developed in our group. Within the various reaction systems such as metal halides—benzyl alcohol, metal alkoxides—benzyl alcohol, metal alkoxides—ketones, metal acetylacetonates—benzyl alcohol and metal acetylacetonates—benzylamine we will discuss representative examples in order to show the versatility of this approach. The careful characterization of the organic species in the final reaction mixtures provides information about possible condensation mechanisms. Depending on the system several reaction pathways have been postulated: (i) elimination of organic ethers as result of condensation between two metal alkoxide precursors; (ii) C–C bond formation between the alkoxy ligand of the metal alkoxide precursor and the solvent benzyl alcohol under formation of a metal hydroxyl species, which can undergo further condensation; (iii) ketimine and aldol-like condensation steps, which in the metal acetylacetonate systems are preceded by a solvolysis of the precursor, involving C–C bond cleavage. In the second part of the paper we will focus on the synthesis of indium oxide nanoparticles using different precursors and solvents. Indium oxide represents an instructive example how the oxide precursors and the solvents influence the particle morphology. These findings make it possible to tailor particle size and shape of a particular metal oxide by the appropriate choice of the reaction system.     

Synthesis,characterization and application of Cr2O3 nanoparticles as an efficient antibacterial agent

This study focuses on the microwave-assisted synthesis of Cr₂O₃ nanoparticles for the development of antibacterial materials. Characterization techniques including FT-IR spectroscopy, UV–vis spectroscopy, SEM-EDX, and XRD, were employed to analyze the nanoparticles' properties. The antibacterial efficacy against E. coli, S. aureus, B. subtilis, and P. aeruginosa was evaluated, with significant activity observed against all pathogens, highlighting their potential as antibacterial materials. The novelty of this study lies in the synthesis of Cr₂O₃ nanoparticles and their application as potent antibacterial agents against various pathogens. The results of XRD study concludes the average size of Cr₂O₃ nanoparticles as 49.96 nm. The synthesized Cr₂O₃ nanoparticles demonstrated a good zone of inhibition against E. coli (22 mm), S. aureus (19 mm), B. subtilis (18 mm), and P. aeruginosa (21 mm). The findings of the study suggest that Cr₂O₃NPs have potential as a novel antibacterial agent, and further research in this area could lead to the development of new and effective treatments for bacterial infections.     

Facile sonochemical synthesis and photoluminescent properties of lanthanide orthophosphate nanoparticles

Uniform lanthanide orthophosphate LnPO₄ (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho) nanoparticles have been systematically synthesized via a facile, fast, efficient ultrasonic irradiation of inorganic salt aqueous solution under ambient conditions without any surfactant or template. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), photoluminescence (PL) spectra as well as kinetic decays were employed to characterize the samples. The SEM and the TEM images show that the hexagonal structured lanthanide orthophosphate LnPO₄ (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd) products have nanorod bundles morphology, while the tetragonal LnPO₄ (Ln=Tb, Dy, Ho) samples prepared under the same experimental conditions are composed of nanoparticles. HRTEM micrographs and SAED results prove that these nanostructures are polycrystalline in nature. The possible formation mechanism for LnPO₄ (Ln=La-Gd) nanorod bundles is proposed. Eu³⁺-doped LaPO₄ and Tb³⁺-doped CePO₄ samples were also prepared by using the same synthetic process, which exhibit an orange-red (Eu³⁺:⁵D₀-⁷F_{1, 2, 3, 4}) and green (Tb³⁺, ⁵D₄-⁷F_{3, 4, 5, 6}) emission, respectively.     

Nonaqueous synthesis of metal oxide nanoparticles: Short review and doped titanium dioxide as case study for the preparation of transition metal-doped oxide nanoparticles

The liquid-phase synthesis of metal oxide nanoparticles in organic solvents under exclusion of water is nowadays a well-established alternative to aqueous sol–gel chemistry. In this article, we highlight some of the advantages of these routes based on selected examples. The first part reviews some recent developments in the synthesis of ternary metal oxide nanoparticles by surfactant-free nonaqueous sol–gel routes, followed by the discussion of the morphology-controlled synthesis of lanthanum hydroxide nanoparticles, and the presentation of structural peculiarities of manganese oxide nanoparticles with an ordered Mn vacancy superstructure. These examples show that nonaqueous systems, on the one hand, allow the preparation of compositionally complex oxides, and, on the other hand, make use of the organic components (initially present or formed in situ) in the reaction mixture to tailor the morphology. Furthermore, obviously even the crystal structure can differ from the corresponding bulk material like in the case of MnO nanoparticles. In the second part of the paper we present original results regarding the synthesis of dilute magnetic semiconductor TiO₂ nanoparticles doped with cobalt and iron. The structural characterization as well as the magnetic properties with special attention to the doping efficiency is discussed.