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CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF ZnO NANOPARTICLES SYNTHESIZED BY CO PRECIPITATION METHOD
摘要： Objective: In the present study the antibacterial activity of zinc oxide (ZnO) nanoparticles was investigated against gram negative (Escherichia coli and Proteus vulgaris) and gram positive (Staphylococcus aureus and Streptococcus mutans) organisms. Methods: The synthesis of ZnO nanoparticles was carried out by co-precipitation method using zinc sulfate and sodium hydroxide as precursors. These nanoparticles were characterized by XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Radiation), UV-Visible spectroscopy and SEM (Scanning Electron Microscope) with EDX (Energy Dispersive X-ray analysis). As well as antibacterial activity and minimum inhibitory concentration of the nanoparticles were carried out by agar well diffusion method and broth dilution method respectively against gram negative (Escherichia coli and Proteus vulgaris) and gram positive (Staphylococcus aureus and Streptococcus mutans) bacteria. Results: The average crystallite size of ZnO nanoparticles was found to be 35 nm by X-ray diffraction. The vibration bands at 450 and 603 cm-1 which were assigned for ZnO stretching vibration were observed in FTIR spectrum. The optical absorption band at 383 nm was obtained from UV-Visible spectrum. Spherical shape morphology was observed in SEM studies. The antibacterial assay clearly expressed that E. coli showed a maximum zone of inhibition (32±0.20 mm) followed by Proteus vulgaris (30±0.45 nm) at 50 mg/ml concentration of ZnO nanoparticles. Conclusion: Zinc oxide nanoparticles have exhibited good antibacterial activity with gram negative bacteria when compared to gram positive bacteria.
关键词： EDX,SEM,MIC,FTIR,UV-VISIBLE spectroscopy,XRD,ZnO nanoparticles
更新于2025-11-21 11:18:25
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A systematic approach to ZnO nanoparticle-assisted electron transport bilayer for high efficiency and stable perovskite solar cells
摘要： Minimizing the interface loss of perovskite solar cells is critical to achieving high photovoltaic performance, and intensive research is underway on interfacial engineering in this regard. In this work, we introduce a ZnO nanoparticles (ZnO NPs) interlayer between phenyl-C61-butyric acid methyl ester (PCBM) and a metal electrode in order to reduce the interface loss due to charge recombination and device degradation, and also investigate the dependence of device performance on the thickness and morphology of the PCBM and PCBM/ZnO electron transport bilayer. After achieving optimized PCBM and ZnO thickness, the PCBM/ZnO bilayer-based devices reached an average power conversion efficiency of 15.63% (Max. 16.39%) with an open circuit voltage of 1.05 V, short circuit current density of 18.69 mA cm-2, and fill factor of 79.95%. In addition, hysteresis behavior and atmospheric stability are significantly improved by the incorporation of a PCBM/ZnO bilayer. Therefore, the implementation of a PCBM/ZnO electron transport bilayer is a promising approach toward achieving a high-efficiency PSC with stable power output (low J-V hysteresis) and durability.
关键词： ZnO nanoparticles,interfacial engineering,stable perovskite solar cells,interface loss,high-efficiency perovskite solar cells,electron transport bilayer
更新于2025-11-19 16:46:39
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GaxSe10-x based solar cells: Some alternatives for the improvement in their performance parameters
摘要： We report on strategies that improve Se-derivative based solar cells performance. With this aim, a compact thin film based on ZnO nanoparticles is deposited onto fluorine doped tin oxide (FTO) as an electron-transport layer, in thermally evaporated GaxSe10-x based solar cells. ZnO nanoparticles films are synthesized by sol-gel process whereas GaxSe10-x material is obtained by mechanical alloying. Using current-voltage measurements, impedance spectroscopy, and capacitance-voltage profiling, device characteristics and performance limiting factors are revealed and discussed. Particularly, the use of ZnO nanoparticles results in improved device performance as well as long-term stability. In comparison to Se-only devices with the structure FTO/Se/Au (power conversion efficiency of 0.98%), under 100 mW/cm2 AM 1.5 G illumination the devices achieved a power conversion efficiency of 2.7% with the structure FTO/ZnO/GaSe9/Au (open circuit voltage of 0.71 V, short-circuit current of 7.9 mA/cm2). Hence, an increase of around 175% in the power conversion efficiency is obtained in comparison to Se-only devices. In addition, the effect of others parameters, like thickness of the active layer as well as the gallium contents in the alloy, are discussed.
关键词： Gallium selenide,Solar cells,ZnO nanoparticles,Electric modulus spectroscopy
更新于2025-10-22 19:40:53
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Subchronic intravenous toxicity study of biofunctional ZnO and its application as a fluorescence probe for cell-specific targeting
摘要： Successful development of safe and highly effective nanoprobes for targeted imaging of in vivo early cancer is a great challenge. Herein, we choose the visible‐light emitting zinc oxide non–core/shell type nanoparticle (NP) fluorophores (ZHIE) as prototypical materials. We have reported on these materials previously. The results showed that the ZHIE NPs exhibited good water solubility and good biocompatibility. This study was conducted to investigate the toxicity of ZHIE NPs when intravenously administered to mice repeatedly at the dose required for successful tumor imaging in vivo. Anti‐macrophage‐1 antigen (Mac1), a macrophage differentiation antigen, antibody‐conjugated ZHIE NPs successfully realized targeted imaging of murine macrophage cell line Raw264.7 cells. In conclusion, ZHIE NPs are not toxic in vivo and antibody‐conjugated ZHIE NPs have great potential in applications, such as single cell labeling.
关键词： subchronic toxicity,zinc oxide (ZnO) nanoparticles,fluorescence probe
更新于2025-09-23 15:23:52
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Grafting Corroles onto ZnO nanoparticles
摘要： Two different copper and gallium arylcorroles have been functionalized using the Vilsmeier–Haack reaction. A further Knoevenagel reaction with cyanoacetic acid was performed on both complexes, affording the desired products with yields above 90%. The newly synthesized compounds have been thoroughly characterized by a combination of spectroscopic methods, optical analyses, and X-ray crystallography. Moreover, they have been tested as anchoring groups for the hydrothermal synthesis of ZnO nanoparticles. The morphology of the heterogeneous composites has been studied by SEM, EDS and fluorescence microscopy analyses, thus confirming the presence of the corrole macrocycle in the hybrid material.
关键词： Corroles,ZnO nanoparticles,Anchoring group,Fluorescence,Knoevenagel reaction
更新于2025-09-23 15:22:29
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Chemometrics-assisted determination of Sudan dyes using zinc oxide nanoparticle-based electrochemical sensor
摘要： Multivariate curve resolution-alternating least squares (MCR-ALS) assisted with electrochemical techniques was applied for simultaneous determination of Sudan II and III at a surface of zinc oxide nanoparticles (ZnONPs) modified carbon paste electrode. Characterization of the ZnONPs and the nanostructured modified electrode was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. Response surface methodology using central composite rotatable design was employed to design of experiments and achieving to optimum values of variables. For simultaneous determination of Sudan II and III, electrochemical second order data were obtained by changing of pulse height in differential pulse voltammetry technique. MCR-ALS was performed on the data to obtain the decomposition peaks of analytes. Then, the detection limits were obtained 1.87 and 2.62 nM for Sudan II and III, respectively. Finally, this method used for the analysis of the two analytes in real samples.
关键词： ZnO nanoparticles,Differential pulse voltammetry,MCR-ALS,Sudan dyes,Second order data,Response surface methodology
更新于2025-09-23 15:22:29
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Generation of ZnO nanoparticles for long-term exposure experiments
摘要： A method of continual ZnO nanoparticle generation was tested for use in follow-up long-term inhalation exposure experiments with small laboratory animals. Nanoparticles were synthesized in an externally heated tube reactor by the evaporation of metallic zinc into a stream of nitrogen carrier gas, followed by the oxidation of zinc vapor in a stream of air and the formation of nanoparticles by a chemical vapor condensation method. The nanoparticle production was studied at various evaporation temperatures, reactor flow rates and flow rates of mixing air. Particle generation for more than 100 h in two experimental runs with one batch of the zinc precursor was performed without a considerable decrease in the particle production rate. As a result, particle production with a number concentration much greater than 1.0 107 #/cm3, a mean particle/agglomerate size well below 50 nm and an emission rate greater than 5 μg/min was obtained under most of the investigated experimental conditions. A maximum emission rate of 16.3 μg/min was obtained at an evaporation temperature of 530 °C, a reactor flow rate of 800 cm3/min and a mixing flow rate of 2000 cm3/min and could be further increased by an increase in the evaporation temperature. The particle characteristics were studied, and estimates of the lung surface deposition area were calculated on the basis of the model developed by the International Commission of Radiological Protection.
关键词： ZnO nanoparticles,Nanoparticle generation,Evaporation/CVS method,LSDA,Hot-wall reactor
更新于2025-09-23 15:21:21
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Antibacterial activity of Fe-doped ZnO nanoparticles synthesised via pulsed laser ablation in liquid against <i>Staphylococcus Aureus</i>
摘要： Pulse laser ablation in liquid (PLAL) technique has been performed in pure water as the solution to produce ZnO and Fe-doped ZnO nanoparticles, by varying Fe ablation time 5, 10 and 15 min. The characterisation was carried out using UV–vis spectrometer, photoluminescence 325 spectrometer, X-Ray diffraction, and high resolution-transmission electron microscopy (HR-TEM). The band gap energy was found to be 3.18 eV for pure ZnO and it was decreased down to 2.86 eV for ZnO for the highest Fe concentration. The shape and size, which were obtained from TEM, showed no significant change of ZnO nanoparticles with and without Fe addition. All samples were tested to inactivate Staphylococcus aureus (S. aureus) growth, which shows promising antibacterial properties as they are able to inactivate bacteria under normal ambient laboratory light, especially Fe-doped ZnO which is able to reduce more bacteria than pure ZnO.
关键词： ZnO,antibacterial,Fe-ZnO,nanoparticles,laser ablation
更新于2025-09-23 15:21:01
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Synthesis, characterization, and cytotoxicity assessment of N-acetyl-L-cysteine capped ZnO nanoparticles as camptothecin delivery system
摘要： The chemical stability, good biocompatibility and high drug loading capacity of zinc oxide nanoparticles (ZnO NPs) and their biomedical potentials make them a promising candidate for drug delivery. The aim of this study was to develop and assess a simple procedure for surface functionalization of ZnO NPs by N-acetyl-L-cysteine (NAC) for anticancer camptothecin (CPT) delivery. NAC capped ZnO NPs were successfully made using ZnCl2 and NaOH in the presence of NAC. CPT was covalently conjugated to the surface of as-synthesized ZnO-NAC NPs. To characterize the synthesized conjugate product (ZnO-NAC-CPT NPs), X-ray diffraction, Fourier Transform Infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and dynamic light scattering method were used. Our results indicated that the ZnO-NAC-CPT NPs exhibit near-spherical morphology and uniform dispersion with an average diameter of ~70 nm. The hemolysis assay showed that ZnO-NAC-CPT NPs has almost no hemolytic activity. In addition, MTT cytotoxicity assessment on A549 lung cancer cells revealed a drop of IC50 values from 1.17 μg/mL (free CPT) to 0.66 μg/mL (ZnO-NAC-CPT NPs). This result showed an augmented cancer-inhibitory effect of nanoconjugate complex. In conclusion, the novel ZnO-NAC-CPT NPs could be considered for new therapeutic endeavors.
关键词： surface functionalization,N-acetyl-L-cysteine,camptothecin,ZnO nanoparticles,cytotoxicity
更新于2025-09-23 15:21:01
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Antibacterial activity of ZnO nanoparticles fabricated using laser ablation in solution technique
摘要： The zinc oxide (ZnO) nanoparticles have been produced by using laser ablation in solution technique, resulting nanoparticles with hexagonal wurtzite structure and the size range of 20 – 50 nm. The optical characterization has predicted the nanoparticles band gap at least 3.16 eV. The ZnO nanoparticles were employed as an antibacterial agent for the growth of Escherichia coli (E. coli), and it shows a great potential. Total plate count (TPC) analysis was conducted by applying the ZnO nanoparticles with different concentration of 5%, 10%, 15%, 20%, 25% and 30% (portion of bacteria medium). The 5% concentration could reduce more than half of the E. coli population after 24 hours incubation time. There was no living bacteria detected for 20%, 25% and 30% ZnO concentration.
关键词： ZnO nanoparticles,laser ablation,antibacterial activity,Escherichia coli
更新于2025-09-23 15:19:57