Optical and electrical properties of p-type Ag-doped ZnO nanostructures

Zn_1−xAg_xO nanoparticles (NPs) (x=0, 0.02, 0.04, and 0.06) were synthesized by a sol–gel method. The synthesized undoped ZnO and Zn_1−xAg_xO-NPs were characterized by X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and UV–visible spectroscopy. The XRD patterns indicated that undoped and Ag-doped ZnO crystallize in a hexagonal wurtzite structure. The TEM images showed ZnO NPs with nearly spherical shapes, with particle size distributed over the nanometer range. Evidence of dopant incorporation is demonstrated in the XPS measurements of the Ag-doped ZnO NPs. The Raman measurements indicated that the undoped and Ag-doped ZnO-NPs had a high crystalline quality. From the result of UV–vis, the band-gap values of prepared undoped and Ag-doped ZnO were found to decrease with an increase in Ag concentration. The obtained undoped and Ag-doped ZnO nanoparticles were used as a source material to grow undoped and Ag-doped ZnO nanowires on n-type Si substrates, using a thermal evaporation set-up. Two probe method results indicated that the Ag-doped ZnO nanowires exhibit p-type properties.     

Polymer-assisted freeze-drying synthesis of Ag-doped ZnO nanoparticles with enhanced photocatalytic activity

Ag-doped ZnO nanoparticles with high and stable photocatalytic activity were prepared by polymer-assisted freeze-drying method with simple process and without organic solvents used. The structural morphology and optical properties of Ag-doped ZnO nanoparticles were characterized by X-ray Diffraction (XRD), Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and high resolution TEM (HRTEM) with energy dispersive X-ray spectroscopy, Ultraviolet-visible Diffuse Reflectance Spectroscopy (UV–vis DRS), X-ray Photoelectron Spectroscopy (XPS) and Fourier Transmission Infrared Spectroscopy (FTIR). Moreover, the thermoanalytical measurements (TGA–DTG) analysis is carried out for proper calcination temperature. XRD results show that Ag nanoparticles were successfully doped into ZnO lattice, and UV–vis DRS results indicate that the doped Ag nanoparticles result in ZnO exhibiting enhanced light trapping capability in the 400?nm and 600?nm range. The photocatalytic activity of Ag-doped ZnO was examined by analyzing the degradation of methyl orange (MO) and methylene blue (MB) dyes under UV light and solar light irradiation, and the results show that all Ag-doped ZnO nanoparticles exhibit better photocatalytic activity than those of pure ZnO nanoparticles at the same degradation conditions; especially the synthesized Ag-ZnO nanoparticles are easy to be recycled and have high photocatalytic stability. Based on the experimental results, the photocatalytic electron transfer path and the photocatalytic mechanism of Ag-ZnO nanoparticles under UV and solar irradiation conditions are explained and clarified.     

Highly Efficient Room Temperature Synthesis of Silver‐Doped Zinc Oxide (ZnO:Ag) Nanoparticles: Structural,Optical, and Photocatalytic Properties

Synthesis of silver‐doped zinc oxide (ZnO:Ag) nanoparticles through precipitation method has been reported. The synthesis was conducted at room temperature and no subsequent thermal treatment was applied. ZnO nanoparticles were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), fourier transmission infrared spectroscopy (FTIR), and ultraviolet‐visible (UV–Vis) spectroscopy. Detailed crystallographic investigation was accomplished through Rietveld refinement. The effect of silver content on structural and optical properties of resultant ZnO nanoparticles has been reported. It was found that silver doping results in positional shifts for the XRD peaks and the absorption band edge of ZnO. These were attributed to the substitutional incorporation of Ag⁺ ions into Zn²⁺ sites within the ZnO crystal. In addition, higher silver incorporation resulted in smaller size for ZnO nanoparticles. The photocatalytic activity of the ZnO:Ag nanoparticles was also determined by methylene orange (MO) degradation studies and compared to that of undoped ZnO. Improved photocatalytic activity was obtained for ZnO:Ag nanoparticles. It has been shown that an optimum amount of silver dopant is required to obtain maximum photocatalytic activity.     

Preparation of CdS/TiO2 nanotube arrays and the enhanced photocatalytic property

In this paper, a series of CdS/TiO₂ NTs have been synthesized by SILAR method. The as-prepared CdS/TiO₂ NTs have been analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS), and ultraviolet–visible (UV–vis). And their photocatalytic activities have been investigated on the degradation of methylene blue under simulated solar light irradiation. XRD results indicate that TiO₂ NTs were anatase phase, CdS nanoparticles were hexagonal phase. FESEM results indicate that low deposition concentration can keep the nanotubular structures. UV–vis results indicate that CdS can be used to improve the absorbing capability of TiO₂ NTs for visible light, and the content of CdS affects the band gap. Photocatalytic results indicate that CdS nanoparticles are conducive to improve the photocatalytic efficiency of TiO₂ NTs, and the highest degradation rate can reach 93.8%. And the photocatalytic mechanism of CdS/TiO₂ NTs to methylene blue is also described.     

A novel approach for the synthesis of highly active ZnO/TiO2/Ag2O nanocomposite and its photocatalytic applications

The present work is focused on the preparation of hybrid ZnO/TiO₂/Ag₂O nanocomposite for enhanced photocatalytic activity. The resultant samples are characterized by using XRD, SEM, EDX, HR-TEM, UV-DRS, BET and XPS techniques. X-ray diffraction analysis indicates the co-existence of wurtzite, anatase and cubic phases in ZnO/TiO₂/Ag₂O nanocomposite. The band gap energy value of the photocatalyst is 3.39 eV, which has been evidenced from UV–visible diffuse reflectance spectroscopy measurements. Photocatalytic degradation of methylene blue dye has been investigated by using UV–visible spectrophotometer. From the result, it has been concluded that ZnO/TiO₂/Ag₂O nanocomposite has proven to be an efficient photocatalyst under UV irradiation when compared to that of mono and binary oxide systems. Further, the possible photodegradation mechanism is proposed to support the enhancement of photocatalytic activity towards degradation of dyes.     

The effect of group-I elements on the structural and optical properties of ZnO nanoparticles

Undoped and group-I elements doped ZnO nanoparticles (NPs) (Zn_1?yX_2yO, X=Li, Na, K, and y=0.05) were synthesized by a sol–gel method. Structural and morphological studies of the resulting products were carried out by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The XRD results revealed that the sample products were crystalline with a hexagonal wurtzite phase. The TEM images showed ZnO NPs with nearly spherical shapes with particle size distributed over the nanometer range. In addition, the XRD and TEM results showed a decrease in crystallite and particle sizes of NPs from Li-doped to K-doped ZnO NPs. Crystalline development in the ZnO NPs was investigated by X-ray peak broadening. The size-strain plot (SSP) method was used to study the individual contributions of crystallite sizes and lattice strain on the peak broadening of the undoped and doped ZnO NPs. The effect of doping on the optical band-gap and crystalline quality was also investigated by using photoluminescence (PL) and Raman spectrometers. The Raman spectra of the all ZnO NPs showed a strong E₂(high) peak. The PL spectra exhibited a strong peak in the ultraviolet (UV) region of the electromagnetic spectrum for the all ZnO NPs. The UV peak of the doped ZnO NPs was red-shifted with respect to that of the undoped ZnO NPs.     

Synthesis of Ag3PO4–ZnO nanorod composites with high visible-light photocatalytic activity

Ag₃PO₄ nanoparticles with 50–100 nm in size distributed on the surface of ZnO nanorods with ca. 20 nm in diameter and 1–2 μm in length have been synthesized by a facile method. The Ag₃PO₄–ZnO nanorod composites had much higher photocatalytic activity toward degradation of Rhodamine B (RhB) under visible light irradiation than pure ZnO nanorods, and had better recyclability and stability than pure Ag₃PO₄ nanoparticles. The Ag₃PO₄–ZnO nanorod composite with the molar ratio of Ag₃PO₄:ZnO = 1:40 exhibited the highest photodegradation efficiency of RhB (93%), which was 1.5 times of pure ZnO nanorods.     

Experimental and theoretical study of visible light driven scandium (III) doped ZnO for antibacterial activity

ZnO was doped with Sc(III) ions to obtain a low-cost and environment-friendly antibacterial material with highly synergistic antimicrobial activity. The combination of experimental results and theoretical insights was used to describe the effect of Sc doping on the electronic and structural properties of ZnO. Sc(III)-doped ZnO materials with different Sc(III) contents were deposited on white carbon black (WCB) by a facile sol-gel method. The Sc(III) doped antibacterial materials were characterized by FESEM, EDX, HR-TEM, BET, XPS, XRD, ICP-OES, UV–visible spectroscopy, Fastsage and Materials Studio (MS). The antibacterial activities of Zn WCB and Zn–Sc WCB were determined by counting Escherichia coli (E. coli) and Staphylococcus aureus (S.aureus) colonies on bacterial culture plates. The results show that the specific surface area of Sc-doped Zn on WCB was increased by 31.9 m²/g compared to Zn WCB. The optimum doping ratio of Zn and Sc was determined in Zn_0.9574Sc_0.0426O cut from hexagonal wurtzite structure ZnO. Moreover, pure ZnO and Zn_0.9574Sc_0.0426O models were established by density functional theory (DFT). The experimental results and DFT calculations demonstrated that ZnO WCB possessed excellent antibacterial properties after doping with Sc. This improved antibacterial activity was due to the effects of Sc₂O₃ on the ZnO lattice, which resulted in the generation of excess reactive oxygen species (ROS).     

Europium (Eu3+) - doped ZnO nanostructures: Synthesis,characterization, and photocatalytic,chemical sensing and preliminary assessment of magnetic properties

We have successfully synthesized single-phase wurtzite hexagonal ZnO:Eu³⁺ (1, 5 and 10 mol %) nanoparticles via facile co-precipitation method. The samples have been characterized by powder X-ray diffraction (PXRD), field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), fourier transform infrared (FTIR) and UV–visible spectroscopy. Change in optical band gap is explained by invoking the existence 4f electronic states of Eu³⁺ in the band gap of ZnO. Photocatalytic performance of these samples for degradation of methyl orange (MO), rhodamine B (Rh B) and picric acid (PA) under UV illumination is found to be 3–3.5 times higher than pure ZnO. However, 5 mol% doping exhibited the highest catalytic efficiency. This sample was also highly sensitive and selective for PA, and the limit of detection was: 1.790 μM, 1.140 μM and 1.751 μM for 1, 5 and 10 mol% Eu³⁺ doped ZnO samples respectively. Finally, all samples behave weak ferromagnetically at room temperature, but a systematic increase in the ferromagnetic-like response is noticed with Eu³⁺ concentration, despite finding no evidence of secondary magnetic phases; EuO and Eu₂O₃ from XRD measurements. Conceivably, the observed ferromagnetic order is attributed to defect induced f⁷– ferromagnetism. Indeed, low concentration of Eu³⁺ dopant is found to be more significant, as reported by different groups.     

Preparation and characterization of PS‐PMMA/ZnO nanocomposite films with novel properties of high transparency and UV‐shielding capacity

High transparent and UV‐shielding poly (styrene)‐co‐poly(methyl methacrylate) (PS‐PMMA)/zinc oxide (ZnO) optical nanocomposite films were prepared by solution mixing using methyl ethyl ketone (MEK) as a cosolvent. The films were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–vis) spectra, high‐resolution transmission electron microscopy (HR‐TEM), and atomic force microscope (AFM). Cross‐section HR‐TEM and AFM images showed that the ZnO nanoparticles were uniformly dispersed in the polymer matrix at the nanoscale level. The XRD and FTIR studies indicate that there is no chemical bond or interaction between PS‐PMMA and ZnO nanoparticles in the nanocomposite films. The UV–vis spectra in the wavelength range of 200–800 nm showed that nanocomposite films with ZnO particle contents from 1 to 20 wt % had strong absorption in UV spectrum region and the same transparency as pure PMMA‐PS film in the visible region. The optical properties of polymer are greatly improved by the incorporation of ZnO nanoparticles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Green synthesis of reduced graphene oxide supported TiO2/Co3O4 nanocomposite for photocatalytic degradation of methylene blue and crystal violet

The hybrid rGO-TiO₂/Co₃O₄ nanocomposite was successfully synthesized through co-precipitation method. The structural, morphological, compositional and optical properties of the as synthesized nanocomposite were characterized by X-ray diffraction (XRD), Field Emission scanning electron microscopy (FESEM), energy dispersive X-Ray Spectroscopy (EDS), Fourier transformation infrared spectroscopy (FTIR), UV–visible spectrophotometer (UV–vis) and photoluminescence (PL). XRD, EDS and FTIR confirms the existence of rGO-TiO₂/Co₃O₄ in the prepared nanocomposite. FESEM confirms that the TiO₂/Co₃O₄ nanocomposite are adsorbed on the surface of the rGO. UV–Vis and PL spectra revealed that the absorbance and emission occurred at visible region, which greatly supports the photocatalytic dye degradation through the electron-hole separation. The percentage decolorization of methylene blue dye solution was higher with lesser time compared to crystal violet dye. This result concludes that the commercialization of rGO/TiO₂/Co₃O catalyst may useful for treating various dyes in industries.     

Structural and electrical properties of ZnO:Ag core-shell nanoparticles synthesized by a polymer precursor method

Monodispersed core-shell type ZnO:Ag nanoparticles were synthesized by a polymer precursor method and their structural and electrical properties were reported in detail. The synthesis technique involves a sol-gel type chemical reaction between aqueous solutions of poly-vinyl alcohol (PVA), sucrose and Zn²⁺ salt. The Zn²⁺-PVA-sucrose polymer precursor powders so obtained after the reaction was further explored for the synthesis of ZnO:Ag nanoparticles. The key part of the work lies in the use of polymer coated ZnO nanoparticles as templates to obtain the ZnO core-Ag shell type nanostructures. Structural and spectroscopic analyses of the derived samples were performed with X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The XRD patterns of the ZnO:Ag nanoparticles consist of distinct peaks corresponding to the hexagonal wurtzite type (space group P63mc) crystal structure of ZnO along with the typical peaks of face centered cubic crystal structure of metallic silver. EDS and XPS analyses confirmed the chemical composition and surface structure of the core-shell nanoparticles. Microstructural analysis revealed the monodispersed platelet shaped ZnO nanoparticles with a thin layer of Ag coating on the surface. UV–visible diffuse reflectance studies revealed the effects of Ag coating on the optical properties of the samples. Detail analysis of the dielectric properties of the samples were performed as a function of frequency (1 Hz to 10 MHz) and temperature (300–528 K) to investigate the electrical conduction mechanism in the samples.     

Multifunctional properties of Zn0·9Mn0.05M0.05O (M = Al,Bi, Sr,Ag) nanocrystals-structural and optical study: Enhance sunlight driven photocatalytic activity

Novel Zn_0·95Mn_0·05O and Zn_0·9Mn_0.05M_0.05O (M = Al, Bi, Sr, Ag) nanocrystals were prepared via the co-precipitation technique. The X-ray diffraction pattern confirmed the substitution of Mn, Al, Bi, Sr, and Ag dopants without altering the basic ZnO structure. The microstructural study was performed by employing the Scherrer plot, Williamson-Hall, and SSP methods. The energy bandgap calculated from UV–vis spectra using different methods observed red-shifted by co-doping. The other optical parameters were also studied and discussed in detail. The FTIR spectra confirmed the presence of Zn–O, and Zn-M–O vibrational modes. Raman spectra demonstrated the presence of ZnO phonon modes, and the Raman shift exhibited the structural defects induced by dopants. The PL spectra showed strong NBE and DLE in the UV and visible region due to extrinsic defects. The IV measurements exhibited the enhancement in the electrical conductivity of ZnO by co-doping. The photocatalytic activity was performed under direct sunlight for methyl orange and methylene blue dyes, and the enhanced degradation efficiency was achieved by co-doping. Furthermore, this article enhances the understanding of tuning the physical properties of ZnO by co-doping and introduces a new class of sunlight-driven photocatalysts.     

Impact of vanadium-, sulfur-, and dysprosium-doped zinc oxide nanoparticles on various properties of PVDF/functionalized-PMMA blend nanocomposites: Structural,optical, and morphological studies

The polymeric blend was fabricated with crystalline poly(vinylidene fluoride) (PVDF)/amorphous functionalized-poly(methyl methacrylate) (PMMA) in 70/30 w/w ratio by chemical mixing method. Functionalization of PMMA was achieved with 2-amino-5-nitrobenzoic acid. The prepared polymer blend was used as a matrix to synthesize nanocomposites with undoped/doped zinc oxide (ZnO) nanoparticles. Doping in ZnO was achieved with vanadium, sulfur, and dysprosium elements as a dopant. The structural, optical, electronic, and morphological properties of undoped/doped nanosized ZnO and blended nanocomposites were accessed through sophisticated analytical techniques, that is, Fourier transform infrared (FTIR), ultraviolet–visible (UV–vis), UV–vis–diffuse reflectance spectra, nuclear magnetic resonance, fluorescence spectroscopy, X-ray diffraction (XRD), transmission electron microscopy, and scanning electron microscopy. The FTIR band at 1165–1176 cm⁻¹ in functionalized-PMMA indicate the formation of aliphatic C-N bond along with aromatic ¹H chemical shift (δ) at 7.134, 7.829 and 8.210 ppm confirm the successfully functionalization of PMMA. The prominent XRD peak at 2θ = 20.8° in nanocomposites shown improvement in β-phase of PVDF. The results show that Dy doped ZnO nanoparticles create remarkable effect on various properties of nanocomposites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47116.     

Sol–gel preparation and characterization of antibacterial and self-cleaning hybrid nanocomposite coatings

ZnO–TiO₂, SiO₂–TiO₂, and SiO₂–TiO₂–ZnO hybrid nanocomposite coatings were synthesized based on sol–gel precursors including tetramethoxysilane (TMOS), 3-glycidoxypropyl trimethoxysilane (GPTMS), tetra(n-butyl orthotitanate) (TBT), and zinc acetate dihydrate. The hybrid network was characterized by FTIR, FESEM, and EDAX techniques. Results indicated that inorganic particles’ size was of nanoorder (20–30 nm), with very uniform distribution and dispersion. Photocatalytic and self-cleaning activities of these coatings were further investigated by degradation of methylene blue in an aqueous solution (20 ppm) at visible light irradiation, indicating photocatalytic performance of the coatings containing ZnO and TiO₂ nanoparticles. The antibacterial effect of the coatings was investigated for inhibition and inactivation of cell growth, with the results showing the same antibacterial activity for ZnO–TiO₂ and SiO₂–TiO₂–ZnO coatings against Escherichia coli and Staphylococcus aureus; the activity was, however, higher than that of SiO₂–TiO₂ hybrid nanocomposite coatings.     

Effect of zinc precursor ratio on morphology and luminescent properties of ZnO nanoparticles synthesized in CTAB medium

In this study, the effect of zinc precursor ratio on structural, morphology and luminescent properties of zinc oxide (ZnO) nanoparticles (NPs) prepared by cationic surfactant-assisted method was studied. ZnO NPs were prepared at room temperature by increasing Zn²⁺: CTAB mole ratio. The pristine ZnO samples showed phase-purity (without need for calcination) as shown by X-ray diffractograms (XRD). Nitrogen adsorption ? desorption analysis showed that the samples exhibit Type III isotherm and H3 hysteresis with mesoporosity. The triangular- to quadrilateral-shaped morphological evolution of the ZnO NPs with increasing concentrations of zinc ions was confirmed by SEM and TEM images of the samples. The UV–Vis–DRS studies showed blue-shifted λ_max (band gap) in all the ZnO samples which indicated their nanostructured nature. The photoluminescence spectra of these ZnO samples show emissions in UV and visible regions. The mechanism of formation of nanostructured ZnO was suggested based on the model reported for mesoporous silica synthesized in CTAB medium.     

ZnO–SnO2 nanocubes for fluorescence sensing and dye degradation applications

ZnO–SnO₂ nanocubes were used as promising material for efficient sensing of p-nitrophenol and faster photocatalytic degradations of dyes like methyl orange (MO), methylene Blue (MB) and acid orange 74 (AO74). ZnO–SnO₂ nanocubes were prepared by the facile solution process at 50 °C using Zn(NO₃)₂·6H₂O and SnCl₂·2H₂O as a precursor in the presence of ethylenediammine. The synthesized material was examined for its morphological, structural, crystalline, optical, vibrational, and compositional studies by using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy. FESEM studies revealed the formation of well-defined ZnO–SnO₂ nanocubes where the structural examinations revealed the formation of a crystalline tetragonal rutile phase for SnO₂ with some crystal sites doped with Zn. The as-synthesized nanocubes were explored for their photocatalytic activities towards three different dye viz. MO, MB, and AO74. Practically, complete degradation of AO74 was seen within 4 minutes of photo-irradiation in the presence of 0.05 g ZnO–SnO₂ nanocubes. However, 97.17% and 41.63% degradations were observed for MB and MO within 15 and 60 minutes, respectively. All the dye degradation processes followed the pseudo-first-order kinetic model. Moreover, the as-synthesized nanocubes were utilized to fabricate highly sensitive and selective fluorescent chemical sensor for the detection of p-nitrophenol (PNP). ZnO–SnO₂ nanocubes showed a very low detection limit of 4.09 μM for the detection of PNP as calculated according to the 3σ IUPAC criteria. Further, the as-synthesized ZnO–SnO₂ nanotubes were found to be highly selective for p-nitrophenol as compared to the other two isomers.     

Enhancement in the photocatalytic and antimicrobial properties of ZnO nanoparticles by structural variations and energy bandgap tuning through Fe and Co co-doping

In this study, pure ZnO and iron (Fe) and cobalt (Co) co-doped ZnO nanoparticles were synthesized by varying Fe and Co concentrations using the co-precipitation method. The physical properties of as-prepared samples were investigated through XRD, FTIR, SEM, and UV–vis spectroscopy. X-ray diffraction confirmed the strong influence of Fe and Co ions on structural parameters without disturbing the basic ZnO hexagonal structure. The microstructural study was executed by using the Scherrer, W–H, and SSP methods. FTIR confirmed the presence of Zn–O, and Zn–M–O (M = Fe, Co) vibrational modes, which further confirmed the successful incorporation of dopants ions. The energy bandgap (E_g) extracted from UV–vis spectra has shown red-shift (3.37–2.7 eV) for decreasing Fe contents, whereas blue-shift (3.37–3.39 eV) for increasing Co concentration. SEM was used to investigate surface morphology, which represents the high rate of agglomeration. The photocatalytic test was performed on grown samples against various dyes and also observed the effects of varying concentrations of Fe and Co ions. The maximum degradation efficiency (98.8%) at 6%Fe and 4%Co under direct sunlight in 60 min against methylene blue (MB) was achieved. The photocatalytic activity of optimized concentration (6%Fe and 4%Co) was further tested against cresol red (CR), methyl orange (MO), safranin-O (SO), rhodamine-B (RhB), and methyl red (MR) dyes. The maximum degradation efficiency against MR dye (96.0%) was observed. The antibacterial test against Staphylococcus aureus and Klebsiella pneumoniae bacterial strains have shown that co-doped ZnO nanoparticles have a higher activity as compared to pristine ZnO, and furthermore, the sample with 6%Fe and 4%Co concentration exposed the highest antibacterial actively for both bacterial strains.     

Novel synthesis of ZnO nanoparticles and their enhanced anticancer activity: Role of ZnO as a drug carrier

In this work, a simple and versatile technique was developed to prepare highly crystalline ZnO nanoparticles (ZnO NPs) by organic precursor method using 5, 6 dimethyl benzimidazole and Zn(CH₃COO)₂·2H₂O followed by calcination. These synthesized ZnO NPs were used as a drug carrier to form 5-Fluorouracil (5 Fu) encapsulated ZnO NPs by varying the molar ratio (100–300:1) of ZnO NPs to 5-Fu. X-ray diffraction (XRD) results indicated that the ZnO NPs had single phase nature with the wurtzite structure. Field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM) results showed nanometer dimension of the NPs. FTIR analysis further reaffirmed the formation/encapsulation of ZnO NPs. UV–vis spectroscopy determined the encapsulation efficiency (EE) and loading capacity (LC) of 5-Fu drug on ZnO NPs. HPLC analysis of encapsulated NPs indicated release of 5-Fu was higher at tumor cell pH (pH 6.0) than physiological pH. Moreover, the anti-tumor activity of ZnO NPs and 5-Fu-encapsulated ZnO NPs investigated using flow cytometry demonstrated that 5-Fu encapsulated ZnO NPs have more anti-tumor activities than 5-Fu itself toward MCF-7 (Breast cancer) cell line. Also, cytotoxicity of MCF-7 increased with the increase of ZnO NPs: 5-Fu ratio. This research will introduce a new concept to synthesize 5-fluorouracil encapsulated ZnO NPs and its application towards the cancer cell line. Thus, the ZnO NPs could not only apply as the drug carrier to deliver 5-Fluorouracil into the cancer cells, but also enhances anti-tumor activity.     

Effect of Biopolymer Blend Matrix on Structural,Optical and Biological Properties of Chitosan–Agar Blend ZnO Nanocomposites

The present research is focused on the development of ecofriendly biopolymer blend based nanocomposites to enhance the effect of cytotoxic activity. Novel eco-friendly synthesis of pure Chitosan–Agar blend and Chitosan–Agar/ZnO nanocomposites was successfully synthesized by in-situ chemical synthesis method. The influence of Chitosan–Agar (1:1 wt/wt%) concentrations (0.1, 0.5, 1 and 3 g) was studied. The presence of ZnO nanoparticles in Chitosan–Agar polymer matrix was confirmed by UV, FTIR, XRD, FESEM, EDAX and TEM. The crystallite size of the nanocomposites in the range of 12–17 nm is observed from XRD analysis. PL and UV reveal that Nanocomposites shows an blue shift by increase in the blend concentrations. TEM analysis shows that 0.1 and 3 g of Chitosan–Agar/ZnO Nanocomposites are in spindle and spherical shape with polycrystalline nature. The prepared Nanocomposites shows the respectable Antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Pseudomonas aureginosa and Klebsilla pneumonia) bacteria. The potential toxicity of Chitosan–Agar/ZnO nanocomposites was studied for normal (L929) and breast cancer cell line (MB231). The result of this investigation shows that the Chitosan–Agar/ZnO nanocomposites deliver a dose dependent toxicity in normal and cancer cell line.