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Biocompatible pure ZnO nanoparticles-3D bacterial cellulose biointerfaces with antibacterial properties
摘要： In this paper, we present for the first time the obtaining and characterization of new antibacterial and biocompatible nano-ZnO–bacterial cellulose (BC) material with controlled interfaces for studying in vitro microorganisms (Escherichia Coli (ATCC 8737), B. subtilis Spizizenii Nakamura (ATCC 6633), Candida albicans (ATCC10231)) and mammalian cells (human dermal fibroblast cells) response. The use of BC based material with controlled characteristics in terms of quantity and distribution of ZnO onto BC membrane (with 2D and 3D fibers arrangement) is directly correlated with the surface chemical and topographical properties, the method of preparation, and also with the type of cells implied for the specific application within the bioengineering fields. In our study, the uniform distribution and the control on the quantity of ZnO nanoparticles onto 3D BC were obtained using matrix assisted pulsed laser evaporation (MAPLE) method. The influence on particle distribution onto 3D bio cellulose were investigated based on two types of solvents (water and chloroform) involved in target preparation within MAPLE deposition. The attachment of the nanoparticles to the bacterial cellulose surface and fibrils was demonstrated by SEM and FT-IR studies. The BC-ZnO showed both resistance to bacteria-sticking and non-cytotoxic effect on the human dermal fibroblasts cells at a mass distribution onto surface of 1.68 mg ZnO NPS/mm2. These results represent a good premise in terms of tailoring BC substrates with ZnO particles that could determine or enhance both the biocompatibility and antibacterial properties of BC-composite materials.
关键词： Antibacterial effect,Zinc oxide nanoparticles,MAPLE deposition technique,Bacterial cellulose,Biocompatibility
更新于2025-09-23 15:23:52
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Physico-mechanical and antimicrobial properties of an orthodontic adhesive containing cationic curcumin doped zinc oxide nanoparticles subjected to photodynamic therapy
摘要： Background: Potential complications on the crown level during fixed orthodontic procedures are white spot, enamel demineralization and the tooth decay. This study evaluated the antimicrobial properties of an orthodontic adhesive incorporating cationic curcumin doped zinc oxide nanoparticles (cCur/ZnONPs), which can have the highest concentration of cCur/ZnONPs and shear bond strength (SBS) value simultaneously, on the against cariogenic bacteria including Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus acidophilus. Materials and methods: Following synthesis and confirmation of cCur/ZnONPs, SBS and adhesive remnant index (ARI) of the test adhesives containing cCur/ZnONPs (1.2, 2.5, 5, 7.5, and 10% wt.) were measured using universal testing machine and stereomicroscope, respectively. After continuously rinsed (up to 180 day), the residual antimicrobial ability of modified adhesives which can have the highest concentration of cCur/ZnONPs and SBS value simultaneously were determined by disc agar diffusion (DAD), biofilm formation inhibition, and metabolic activity assays following photo-activation using light-emitting diode (LED) for 5 min against multispecies cariogenic biofilm-producing bacteria. Results: Adhesive with 7.5% wt. cCur/ZnONPs showed the highest concentration of cCur/ZnONPs and SBS value (14.89 ± 3.26 MPa, P < 0.05) simultaneously. No significant differences in ARI scores were found between the modified adhesive and control (Transbond XT without the cCur/ZnONPs). 7.5% wt. cCur/ZnONPs following photo-activation was not colonized by the test microorganisms and suppressed 100% metabolic activity of the test microorganisms up to 90 day compared to the control group (cCur/ZnONPs free LED irradiation; P < 0.05). In DAD assay, the reduction of photodynamic disinfection of the 7.5% wt. cCur/ZnONPs against test bacteria was positively associated to the time, in such a way that it was decreased significantly after 60 day. From days 120 onwards, microbial biofilm formation and metabolic activity was progressively increased on 7.5% wt. cCur/ZnONPs adhesive discs compared to the control group (cCur/ZnONPs free LED irradiation). Conclusions: Our findings highlight the photo-activated 7.5% wt. cCur/ZnONPs can serve as an orthodontic adhesive additive for control the cariogenic multispecies biofilm, and also to reduce their metabolic activity.
关键词： Cariogenic bacteria,Orthodontic adhesive,Antimicrobial photodynamic therapy,Cationic curcumin,Zinc oxide nanoparticles
更新于2025-09-23 15:23:52
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Mini submersible pump assisted sonochemical reactors: Large-scale synthesis of zinc oxide nanoparticles and nanoleaves for antibacterial and anti-counterfeiting applications
摘要： Low cost, environmentally friendly and industrial-scale approaches for the synthesis of anti-counterfeiting and antibacterial materials are a challenging task. The current research reports novel and inexpensive approaches for the synthesis of zinc oxide nanostructures (ZnO-NSs) using Mini Submersible Pump (MSP) assisted sonochemical reactors. Zinc oxide nanoleaves (ZnO-NLs) were synthesized using MSP assisted sonochemical mixing reactor at gram-scale (4 g). Zinc oxide nanoparticles (ZnO-NPs) were synthesized using MSP assisted sonochemical flow loop reactor at gram-scale (11.5 g). Synthesized ZnO-NSs were characterized by UV-visible spectroscopy, fluorescence spectroscopy, XRD, FTIR, TGA, BET, FEG-SEM, and FEG-TEM. Bare ZnO-NPs and ZnO-NPs coated cotton fabric showed high antibacterial activity against diseases causing Gram-positive bacteria Staphylococcus aureus. Based on the UV fluorescence property of the ZnO-NLs, invisible security ink was developed for anti-counterfeiting applications. The invisible security ink was tested as a rubber stamp and fountain pen inks which were found to be stable on the various kinds of microporous papers. As compared to our previously reported method, disperser assisted sonochemical approach for ZnO-NLs synthesis; the current approach reduces the cost of equipment used from ~1700 to 4 USD. Both reactors are designed simply (less complicated), based on an environmentally friendly approach, highly scalable, increases the effectiveness of the sonochemical technique and suitable for industrial applications.
关键词： antibacterial,anti-counterfeiting,sonochemical reactors,Mini submersible pump,zinc oxide nanoparticles and nanoleaves
更新于2025-09-23 15:22:29
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Structural, optical and photocatlytic properties of zinc oxide nanoparticles obtained by simple plant extract mediated synthesis
摘要： We report a facile and inexpensive method to prepare zinc oxide nanoparticles with different particle size and shape using Achyranthes aspera and Couroupita guianensis leaf extracts as the reducing agent and zinc nitrate as a precursor. The prepared zinc oxide nanoparticles were analyzed by various characterization methods and obtained results evidently revealed that crystalline parameter, purity, optical absorption, band gap, particle size and shape of the ZnO nanoparticles significantly influenced by the type of leaf extract used as reducing agent. Further, photocatlytic activity study obviously demonstrates that prepared samples exhibits superior photocatlytic activity for the degradation of methylene blue dye by creating superoxide anion radicals and OH radicals under photonic irradiation. Hence, prepared zinc oxide nanoparticles by plant extract mediated synthesis can be applied as a photocatlyst for the possible waste water treatment in textile industry.
关键词： Waste water treatment,Photocatalytic activity,Plant extract mediated synthesis,Methylene blue dye,Zinc oxide nanoparticles
更新于2025-09-23 15:21:21
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Zinc Oxide Nanoparticles Synthesized by Suaeda japonica Makino and Their Photocatalytic Degradation of Methylene Blue
摘要： Green chemistry gained special attention for the environmental safety. In addition, green synthesized plant based nanoparticles for the degradation of industrial pollutant dye also received special focuses. Thus, photocatalytic activity of nanosized zinc oxide (Sj-ZnONps) synthesized by a simple co-precipitation method using sodium hydroxide, zinc nitrate, and Suaeda japonica extract as starting materials was carried out. The reaction was implemented in comparatively low temperature (50oC) without further calcination. The absorption spectrum demonstrated an extinction peak at ~362 nm, which is characteristic to the ZnO nanoparticles. Field-emission transmission electron microscope revealed smaller agglomeration of hexagonal Sj-ZnONps (~100 nm). X-ray diffraction patterns exposed polycrystalline ZnO with hexagonal wurtzite structure. The self-assembly of Sj-ZnONps was achieved due to the capping of phytoconstituents present in extract as evident from Fourier-transform infrared spectroscopy analysis. The photocatalytic degradation of Sj-ZnONps was estimated in reduction of methylene blue (MB). The reaction mixtures comprising of MB, S. japonica extract and Sj-ZnONps had the most significant decrease of MB by 54 %. In conclusion, the Sj-ZnONps can be used as a photocatalyst for decomposition of organic pollutions present in water.
关键词： Photocatalytic degradation,Green synthesis,Suaeda japonica Makino,Methylene blue,Zinc oxide nanoparticles
更新于2025-09-23 15:21:21
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Laser Reduction of Graphene Oxide/Zinc Oxide Nanoparticle Nanocomposites as a Onea??Step Process for Supercapacitor Fabrication
摘要： Herein, the laser reduction of graphene oxide (GO) and zinc oxide nanoparticle (ZnONP) nanocomposite ?lms is proposed as a one-step process for supercapacitor fabrication. The ?lms, deposited by casting onto a ?exible poly(ethylene terephthalate) (PET) substrate coated with indium-doped tin oxide (ITO), are subjected to laser irradiation (5 mW, 405 nm) to reduce the GO phase and produce laser-reduced GO (LRGO). Scanning electron microscopy/energy dispersion spectroscopy (SEM–EDS), micro-Raman spectroscopy, and current versus voltage (I(cid:1) V) analyses show a partial reduction of GO to LRGO, forming several conductor-insulating (LRGO/GO) microporous interfaces, and thereby favoring the formation of a supercapacitor structure. Moreover, the topmost LRGO ?lm layer is extensively reduced, making it suf?ciently conducting to work as the counter electrode as well. However, the reduction process is less effective when ZnONPs are introduced into the GO matrix because ZnONPs get clustered and scatter the incident laser before reaching the GO phase. The capacitive behavior, assessed by cyclic voltammetry and galvanostatic charge–discharge measurements, reveals the following (cid:3)1 (GO/LRGO/ ZnONP). The method proposed herein is advantageous because it produces the microcapacitor structures and LRGO counter electrode in a single laser reduction step.
关键词： laser-reduced graphene oxide,graphene oxide,nanocomposites,micro-heterojunctions,zinc oxide nanoparticles
更新于2025-09-23 15:21:01
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Al-, Ga-, Mg-, or Li-doped zinc oxide nanoparticles as electron transport layers for quantum dot light-emitting diodes
摘要： Colloidal quantum dots and other semiconductor nanocrystals are essential components of next-generation lighting and display devices. Due to their easily tunable and narrow emission band and near-unity fluorescence quantum yield, they allow cost-efficient fabrication of bright, pure-color and wide-gamut light emitting diodes (LEDs) and displays. A critical improvement in the quantum dot LED (QLED) technology was achieved when zinc oxide nanoparticles (NPs) were first introduced as an electron transport layer (ETL) material, which tremendously enhanced the device brightness and current efficiency due to the high mobility of electrons in ZnO and favorable alignment of its energy bands. During the next decade, the strategy of ZnO NP doping allowed the fabrication of QLEDs with a brightness of about 200 000 cd/m2 and current efficiency over 60 cd/A. On the other hand, the known ZnO doping approaches rely on a very fine tuning of the energy levels of the ZnO NP conduction band minimum; hence, selection of the appropriate dopant that would ensure the best device characteristics is often ambiguous. Here we address this problem via detailed comparison of QLEDs whose ETLs are formed by a set of ZnO NPs doped with Al, Ga, Mg, or Li. Although magnesium-doped ZnO NPs are the most common ETL material used in recently designed QLEDs, our experiments have shown that their aluminum-doped counterparts ensure better device performance in terms of brightness, current efficiency and turn-on voltage. These findings allow us to suggest ZnO NPs doped with Al as the best ETL material to be used in future QLEDs.
关键词： electron transport layer,doping,zinc oxide nanoparticles,light-emitting diodes,quantum dots
更新于2025-09-23 15:21:01
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Removal of humic acid from <b>aqueous solutions</b> using ultraviolet irradiation coupled with hydrogen peroxide and zinc oxide nanoparticles
摘要： In this study, individual performance of ultraviolet irradiation (UV), zinc oxide nanoparticles (ZnO) and hydrogen peroxide (H2O2) processes, as well as a performance of combined processes of UV/H2O2 and UV/H2O2/ZnO, were assessed for the removal of humic acid (HA) from aqueous solutions. Various process-related factors, such as the concentration of ZnO (0.2 and 0.5 g/L), the concentration of H2O2 (20, 30 and 50 mg/L), UV = 125 W, pH (4, 7 and 10), initial HA concentrations (at wavelength of 254 nm) of 2, 5, 7 and 10 mg/L, and three types of interferences (nitrate, sulphate and chloride) were studied and optimised. The results showed that removal e?ciency decreased by increasing the concentration of HA and pH values in all processes, but it increased by increasing the time of exposure and the concentration of H2O2. In the combined process of UV/ZnO/H2O2, the nanoparticle concentration of 0.2 g/L yielded the highest e?ciency, whereas in the other processes, the highest e?ciency was observed at nanoparticle concentration of 0.5 g/L. Based on these results, under the optimum conditions (HA = 2 mg/L, H2O2 = 50 mg/L, ZnO = 0.2 g/L, pH = 4.0 and contact time of 15 min), UV/ZnO/H2O2 process was found as the most e?cient combination in removing of HA with an e?ciency of 99.99%. Furthermore, the modelling results indicated that the adsorption reaction of HA onto ZnO nanoparticles was very well described by the pseudo-second-order kinetic model (R2 > 0.99).
关键词： hydrogen peroxide,Ultraviolet irradiation,zinc oxide nanoparticles,humic acid
更新于2025-09-23 15:19:57
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Nanostructured paper-based platform for phenylalanine neonatal screening by LED-induced fluorescence
摘要： In this work, a novel paper-based analytical device (PAD) coupled to LED-induced fluorescence (LIF) detection (fPAD) for the rapid, selective, and sensitive quantification of phenylalanine (Phe) in neonatal samples was developed. Enzymes Phenylalanine dehydrogenase (PheDH) and diaphorase were immobilized on a paper microzone previously modified with zinc oxide nanoparticles (ZnONPs) coated with chitosan (CH-ZnONPs). Phe was extracted from the blood spots collected samples on filter paper and was mixed with nicotinamide adenine dinucleotide (NAD+) and resazurin. Then the mixture was deposited on the reaction microzone of the fPAD where PheDH converts the Phe and NAD+ to phenylpyruvate and NADH, respectively. Finally, NADH was oxidized by diaphorase with the consequent reduction from resazurin to resorufin. This latter was detected by LIF using an excitation wavelength of 535 nm and an emission of 580 nm in a synchronized video microscope. We compare the responses of the PADs with and without nanomaterials to demonstrate the improved analytical performance of the developed devices. For this, the PADs were modified with the same concentration of horseradish peroxidase (HRP). The fluorescent signal obtained from the PADs with nanomaterials was higher than that of the unmodified PADs. Our method exhibited within- and between-assay variation coefficients below 5.23% and 6.67%, respectively. The detection limit obtained by the developed device was 0.125 μM. The proposed fPAD allowed the simple, rapid, low-cost, and sensitive detection of Phe in neonatal blood samples.
关键词： zinc oxide nanoparticles,Phenylalanine,Paper-based analytical device,Enzymatic method,Fluorometric detection
更新于2025-09-23 15:19:57
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Raman Spectroscopy as an Assay to Disentangle Zinc Oxide Carbon Nanotube Composites for Optimized Uric Acid Detection
摘要： Refluxed zinc oxide (ZnO) nanoparticles (NPs) were prepared and attached to carboxylic acid functionalized multi-walled carbon nanotubes (COOH-MWNTs) via sonication. Practical optimization of electrocatalysts using sonication to disentangle a carbon nanotube composite for monitoring uric acid (UA) is shown. Monitoring UA is important for the management of medical disorders. Selection of sonication time is a crucial step in producing the desired composite. We report, for the first time, the practical use of Raman spectroscopy to tune the sonication involved in tethering ZnO NPs to the multi-walled carbon nanotube (MWNT) surface. Maximum current for detecting UA, using chronoamperometry and cyclic voltammetry, correlated with the highest sp2-hybridized carbon signal, as seen in the integrated Raman G band peak areas denoting maximum COOH-MWNT disentanglement. An array of ZnO/COOH-MWNT composites were prepared ranging from 60 to 240 min sonication times. Optimum sonication (150 min) corresponded with both maximum measured current and MWNT disentanglement. The sensor was able to quantitatively and selectively measure UA at clinically relevant concentrations (100–900 μM) with rapid current response time (< 5 s).
关键词： chronoamperometry,zinc oxide nanoparticles,Raman spectroscopy,cyclic voltammetry,multi-walled carbon nanotubes,electrochemical sensing
更新于2025-09-19 17:15:36