Structural, morphological, optical and biomedical applications of Berberis aristata mediated ZnO and Ag-ZnO nanoparticles

Herein, we prepared the zinc oxide (ZnO) and silver doped zinc oxide (Ag-ZnO) nanoparticles (NPs) using Berberis aristata plant extract as a reducing, capping and stabilizing agent. The x-ray diffraction (XRD) pattern confirms the formation of pure hexagonal wurtzite structure for both the samples with P4mm space group. The crystallite size reduces from 21.313 nm to 18.179 nm with the Scherrer technique with doping of Ag ions on ZnO NPs, while the Williamson Hall (WH) approach likewise demonstrates a decrease in crystallite size from 26.602 nm to 21.522 nm. The lattice strain increases from 0.0031 to 0.0064, indicating the presence of Ag-ions in the crystal lattice of ZnO NPs. For both samples, the metal-oxygen bond formation is supported by the Fourier Transform Infrared (FTIR) spectra. For ZnO, the peak in the UV-visible spectrum is approximately around 365 nm, but for Ag-ZnO, two peaks are observed around 235 nm and 360 nm. With the Ag doping, the bandgap increases from 3.01 eV to 3.02 eV. Transmission Electron Microscopy (TEM) micrographs show the formation of crystalline particles and Field Emission Scanning Electron Microscopy (FESEM) pictures show the formation of aggregated NPs with a spherical shape. Energy Dispersive x-ray Spectroscopy (EDX) and x-ray Photoelectron Spectroscopy (XPS) demonstrate the chemical purity of both the samples. The antibacterial activity of ZnO NPs was highest against Staphylococcus aureus i.e., 15 ± 0.53 mm, whereas, for Ag-ZnO NPs the highest activity was against Salmonella typhi i.e., 19 ± 0.53 mm.


Introduction
The focus of nanotechnology is to study and utilize materials at the nanoscale.Due to features like shape, size, and higher surface area to volume fraction, nanomaterials show novel and improved properties as compared to their bulk counterparts [1].Nanotechnology is becoming more significant in a variety of sectors, including biomedical engineering, electronics, energy, mechanics, agriculture, cosmetics, environmental remediation, and chemical industries [2,3].Zinc oxide (ZnO) nanoparticles (NPs) are one of the well-known nanomaterials because of their outstanding chemical stability, non-toxicity, and cost-effectiveness.They have a wide range of applications in fields like agriculture, environmental remediation, biomedicine, and biosensing [4,5].Due to their photostability, the higher band gap of 3.37 eV, and significant exciton binding energy of 60 MeV, the material exhibits favourable characteristics [6,7].ZnO NPs have demonstrated excellent potential by efficiently interacting with bio-membranes and displaying antibacterial and anticancer activities [8].By doping noble metals or metal ions with inherent semiconductive characteristics to ZnO NPs, it has become possible to induce chemical sensitization from an electrical standpoint [9].Ag is regarded as one of the greatest choices for dopant selection because Ag doping in ZnO is linked to the generation of oxygen vacancies, crystalline alteration, and changes in scattering patterns, Ag-doped ZnO NPs are anticipated to be extensively exploited for their unique physicochemical properties [10].It is observed that the biological applications of the ZnO NPs could be enhanced by Ag-doping on them [11].
Traditionally, NPs have been synthesized by chemical processes that use chemicals as both capping and stabilizing agents.However, recent criticism of such techniques is due to their use of expensive, hazardous, and poisonous materials that have the potential to affect both the environment and human health.This necessitated research into the development of simple, nature-based, and eco-friendly reducing and stabilizing agents for the production of nanoparticles [12,13].There is a pressing need to develop such fabrication processes that don't give out dangerous substances as NPs are regularly used in settings where people come into contact with them.Therefore, a viable replacement for physical and chemical methods is the green synthesis of NPs [14,15].A very practical and affordable technology with a huge amount of potential for growth in the large-scale commercial production of NPs is plant-mediated synthesis, which uses plant extract as a source of phytochemicals [16].Phytochemicals present in the plant extract can reduce metal ions to metal oxides or even to zero valence state metal nanoparticles [17].Multiple studies on plant-mediated synthesis have demonstrated that it can provide more precise size and morphology than some physical and chemical methods [18].ZnO NPs can be synthesized using aqueous plant extract derived from various plant parts such as leaves, flowers, roots, stems, and bark.The synthesis of ZnO NPs through plant-mediated means has sparked our interest due to the presence of secondary metabolites within plants that can reduce Zn precursors and stabilize resulting ZnO NPs.ZnO NPs have been synthesized using various plant parts, including Aquilegia pubiflora [19], Berberis aristata leaf [20], Cannabis sativa leaf [21], Parthenium hysterophorus leaf [22], and Moringa oleifera seeds [11].
Berberis aristata, a versatile plant from the Berberidaceae family of barbed shrubs is native to Mediterranean regions of Asia and Europe [23].'Daruhaldi' and 'Chitra' are some of the common names for the plant Berberis aristata.It is widely referred to as 'Kashmal' in Himachal Pradesh, India.It has been utilized as a part of traditional Chinese medicine and Ayurveda, for past 3000 years, for a variety of treatments.It is used to make 'Rasaut,' an extremely useful Ayurvedic medication [24].It is employed in organized medical systems like Ayurveda, Siddha, and Unani as a single plant treatment or in polyherbal preparations.Classical Ayurvedic scriptures (Sushrut Samhita) have also discussed their usage in the treatment of infected wounds [25].
In the current study, ZnO and Ag-ZnO NPs were synthesized from the valuable medicinal plant Berberis aristata root extract, where root extract was used as a reducing and stabilizing agent.Phytochemical screening was carried out to identify the presence of carbohydrates, phenols, flavonoids, terpenoids, and saponins in the Berberis aristata root extract.The ZnO and Ag-ZnO NPs were characterized through various analytical techniques such as UV-visible spectroscopy, x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS).The antibacterial properties of the ZnO and Ag-ZnO NPs were tested against gram-positive and gram-negative bacteria.To the best of our knowledge, Berberis aristata roots have been utilized for the first time to synthesize ZnO and Ag-ZnO nanoparticles.

Preparation of Berberis aristata root extract
The roots were cleaned with double-distilled water and dried for 20 days in a shady area away from the sun.With the use of an electronic grinder, the dried roots were ground into a fine powder.Soxhlet extraction was used to prepare root extract.A uniformly grounded 100 g of root powder was placed in a thimble and run through a Soxhlet extractor.It was thoroughly extracted with double-distilled water until the solvent in the extractor's siphon tube became colorless.Then the extract was kept in a refrigerator at 4 °C for future experiments.Figure 1 shows the preparation of plant extract.

Qualitative phytochemical screening
The qualitative screening of phytochemicals was conducted using prepared crude extracts with aqueous solvents to ascertain the presence of carbohydrates, phenols, flavonoids, saponin, tannin, terpenoids, and alkaloids.A distinct quantity of 100 mg of unrefined extract was thinned down in 10 ml of identical solvent to conduct a qualitative analysis.To accomplish this, a range of standardized assessments [26][27][28] were administered.

Green synthesis of ZnO and Ag-ZnO NPs
A straightforward, inexpensive, eco-friendly, and widely utilized green method was employed to synthesize ZnO and Ag-ZnO NPs.The method adopted for the synthesis was based on previously published work with slight modifications [33].To synthesize ZnO NPs, 0.5 M solution of zinc acetate dihydrate was prepared in 100 ml double distilled water.The mixture was kept at ambient temperature while being magnetically stirred.The pH of the solution was maintained at ∼12 by adding 10 ml solution of 2 M sodium hydroxide to the previous solution and further stirred for 30 min.After stirring the mixture for around two hours with 25 ml of Berberis aristata root extract added, white precipitates were observed within the mixture.
Similar to this, to synthesize Ag-ZnO NPs, 100 ml of 0.5 M zinc acetate solution and 50 ml of a 0.05 molar solution of silver nitrate were mixed, which were stirred for a further ten minutes at room temperature.The  addition of 10 ml of a 2 M sodium hydroxide solution was followed by 50 min of stirring.To the initial solution, 25 ml of Berberis aristata root fruit extract was added, and the mixture was stirred for two hours.Under constant stirring, after a few hours, black-coloured precipitates were observed.The precipitates then collected using a centrifuge, and contaminants were removed by washing the residue seven times with deionized water.Following that, the samples were dried for 18 h at 60 °C.The prepared powders were examined for their different structural, morphological, optical, and antibacterial characteristics.

Structural and morphological characterization
The structural analysis was conducted utilizing the Ringaku Minifex 600 x-ray powder diffractometer, which employed CuK radiation with a wavelength of 1.5405 nm.The Hitachi SU 8010 field emission scanning electron

Antibacterial assay
The antimicrobial activity of nanoparticles was tested using well diffusion against gram-negative and grampositive bacteria isolates.Among the strains used were Salmonella typhi, Bacillus subtilis, and Staphylococcus aureus.Bacteria were grown on nutrient agar media for the antimicrobial assay.A lawn culture of the aforementioned isolates was created on nutrient agar plates, and wells were created using a puncture to add the 100 μl (100 mg ml −1 ) of sample to the wells, and ampicillin was kept as a positive control for bacterial strains 100 μl (10 mg ml −1 ), and triple distilled autoclaved water was used as a negative control.To allow bacteria to grow, the petri plates were incubated at 37 °C for 16-18 h.All tests were performed in triplicate [34].HiMedia antibiotic zone was used to measure the inhibition zones around the wells, and the diameters of the zones of inhibition were measured in millimeters (mm).

Results and discussion
3.1.Phytochemical analysis 3.1.1.Qualitative phytochemical analysis Table 1 presents the outcome of the preliminary phytochemical screening conducted on the Berberis aristata roots.The aqueous root extract of Berberis aristata was subjected to preliminary phytochemical screening, which revealed the existence of several phytochemicals such as phenols, flavonoids, saponins, alkaloids, carbohydrates, and terpenoids.The presence of tannins was not detected.

Quantitative phytochemical analysis
The findings of the quantitative phytochemical analysis indicated that the aqueous extract of Berberis aristata roots contained, Total Phenol Content (TPC) of 68.55 ± 1.07 mg GAE/g, Total Flavonoid Content (TFC) of

Structural analysis
X-ray diffraction is an analytical technique that is non-destructive and offers comprehensive insights into the chemical composition and crystallographic structures of materials.Figure 3 displays the x-ray diffraction (XRD) pattern of ZnO and Ag-doped ZnO NPs.The distinct diffraction peaks observed in the XRD pattern provided clear evidence of the crystalline structure of the material.The observed peaks were indexed as (100), ( 002), ( 101), ( 102), ( 110), ( 103), ( 200), (112), and (201) correspond to the ZnO phase.The absence of diffraction peaks of impurities in the un-doped ZnO indicated its purity.The hexagonal wurtzite structure was observed in both the samples which is considered to be the most stable phase of zinc oxide [36].According to the standard JCPDS File No 89-7102, the hexagonal wurtzite crystal structure of ZnO is represented by the conventional diffraction peaks [33].The XRD spectrum displayed the same pattern of peaks as seen in the XRD spectrum of ZnO NPs, but due to Ag doping in ZnO, there were extra-sharp peaks indexed as (111) crystal planes corresponding to Ag in reference to the JCPDS File No. 5-2872 [33,37].The fact that these peaks were present suggested the presence of Ag ions in the interstitial sites of ZnO.Crystallite size, D, was calculated using the standard Scherrer's formula [38]; Where D is the average crystallite size, λ (1.54 Å) is the x-ray wavelength, k (0.9) is the Scherrer constant, θ is the Bragg angle, and β is the FWHM of the experimental data.
It was observed that the crystallite size decreased from 21.313 nm to 18.179 nm with the Ag doping on ZnO nanoparticles.This was because the incorporation of Ag ions prevented the grain formation, which then resulted in a reduction in crystallite size [36].
The Williamson-Hall (W-H) plots were obtained for both samples which indicated the anisotropic character of synthesized NPs, as illustrated in figure 4. To obtain the Williamson-Hall plots, the following equation was used which is given below [39]; Where β is full width at half maximum (FWHM), D is the crystallite size, and ε is the strain.The W-H plots were used to determine the crystallite size and lattice strain.The estimated crystallite sizes obtained from the first part of equation (2) were observed as 26.602 nm and 21.512 nm for ZnO and Ag-ZnO, respectively.It was noted that the sizes of the crystallites acquired using the Scherrer formula were lower than those obtained using the W-H approach.In general, Scherrer method measures the cohesion length of the x-rays; any defects or vacancies will cause the measured size to be smaller than the actual size, whereas the W-H method takes micro-strain into account.As a result, the Scherrer method yields smaller crystallite sizes than the William-hall method [21,38].
Further, the lattice strain was also obtained from the second part of the Williamson-Hall equation.The lattice strain was observed to increase from 0.0031 to 0.00644 due to the reason that Zn ions have been replaced by Ag ions in the ZnO crystal lattice.A few ions residing on the crystal structure also contributed to the increase in lattice strain.
The lattice parameters are calculated to find the effect of doping of Ag on ZnO crystal using the following equation [40]; Where, d denotes the interplanar spacing, (hkl) are the miller indices, a and c are the lattice parameters.It was observed that lattice parameter a=b increased from 3.047 Å to 3.048 Å and c increased from 5.277 Å to 5.279 Å with the Ag doping, as presented in table 2. The increase in lattice parameters could be attributed to the ionic radii of Zn and Ag.According to Vegard's law the lattice parameter increases when the dopant of larger ionic radii substitutes the host ion of smaller ionic radii and vice-versa.Similarly, the lattice volume was also observed to increase from 48.992 Å 3 to 49.043 Å 3 with the Ag doping on ZnO.Further, the c a ratio signified the structural traits of the ZnO.The value obtained for c a ratio was 1.73 for both samples which is in agreement with the standard value [6].A small variation was observed because of the reason that the plant extract might have increased the distortion in the crystal structure during the crystal formation [41].
The length of the dislocation lines present per unit volume of the crystal is defined as the dislocation density (δ), which represents the number of defects in the sample.The values of dislocation density are obtained using equation [38]; where D is the crystallite size.Dislocation density gives a quantitative analysis of the crystallinity.The dislocation density was calculated from the crystallite sizes of both methods, i.e., the Scherrer method and the Williamson-Hall method.The dislocation density calculated from the crystallite size of the Scherrer method was 0.00222 nm −2 and 0.00302 nm −2 for ZnO and Ag-ZnO NPs, respectively.However, the dislocation density obtained from the crystallite size of the W-H method is 0.00141 nm −2 to 0.00215 nm −2 .The increase in dislocation density was due to the decrease in crystallite size with the Ag doping on the ZnO crystal lattice.

Optical analysis
A UV-vis spectrometer with a wavelength range of 200-600 nm was used to record the UV-vis spectra of ZnO and Ag-ZnO nanoparticles. Figure 5(a) displays the absorbance spectra.The significant UV absorption peak at 368 nm that was detected in pure ZnO nanoparticles may be related to the crystal structure of ZnO.Two peaks with different and strong intensities were noted at wavelengths 365 and 238 nm, respectively.The first absorption peak was assumed to be caused by the electronic transition of ZnO, and the second peak was thought to be caused by the presence of Ag in Ag-ZnO [42].
From the absorption spectra, the band gap energy was obtained using Tauc's equation [43] for direct band gap material Where hυ denotes the photon energy, Eg denotes the band gap energy, k is a constant and α is the absorption constant.The functional groups involved in the synthesis of the NPs and their distribution on the final ZnO NPs and Ag-ZnO can be determined with the use of FTIR spectroscopy.Figure 6 shows the FTIR spectra of synthesized ZnO and Ag-ZnO nanoparticles, recorded between 400 and 4000 cm −1 .The strong vibrational band, which was in the 400-600 cm −1 range, corresponded to the Zinc and Oxygen bond's typical stretching mode [44].The sharp peak at 400-500 cm −1 was caused by the ZnO stretching mode [45].O-H stretching vibration was attributed to the intense broadband peak in the ZnO and Ag-ZnO samples at about 3400 cm −1 , which denoted the presence of phenolic hydroxyl groups [43].The development of Ag ions on the surface of ZnO reduced the peak's strength in the IR spectra of Ag-ZnO NPs.FTIR spectra demonstrated successful capping of biomolecules on the NPs surface.These biomolecules provided stability to the synthesized NPs.FTIR spectra of plant extract is shown in figure 6(c).The presence of vibrational band within the range of 1300-1700 cm −1 was due to the functional groups of proteins i.e., C=O, −C−N, which resulted in the formation of the amide bands [46].Similarly, the Alcohols and phenols produce characteristic infrared bands due to O-H stretching and C-O stretching in the regions around 1000 cm −1 , whereas, presence of -NH or moisture causes similar results [47].The band between 2800-3000 cm −1 revealed the presence of amines in the plant extract, whereas, the band between 3300-3600 cm −1 was associated with the hydroxyl and phenolic groups.Thus, by comparing the FTIR spectra of ZnO, Ag-doped ZnO, and plant extract, it could be claimed that the plant extract has coated the synthesized nanoparticles which played an important role in the synthesis of nanoparticles.

Morphological analysis
FESEM was used to examine the surface morphology of pure and Ag-doped ZnO, which is depicted in figure 7(a).The FESEM results revealed a spherical shape and the presence of agglomerated nanoparticles.The polarity and electrostatic attraction of ZnO NPs synthesized during green synthesis might be responsible for the agglomeration [48].When Ag-ions were incorporated on the surface of ZnO NPs, there were no major changes in morphology, however, grain growth was observed.Phytochemicals present in plant extract aided in the formation of meso crystals during the self-assembly process.This was a crucial element in the growth of crystals, which resulted in the development of structures [49].
The elemental composition of green synthesized ZnO and Ag-ZnO NPs was determined through EDX analysis.The spectrographic analysis of ZnO using the EDX technique indicated the detection of only Zinc and Oxygen peaks, as illustrated in figure 7(b).The weight percentages of oxygen and Zn were found to be 33.56% and 66.44%, respectively.Additionally, their atomic weight percentages were determined to be 69.82% and 30.18%, respectively.The EDX spectrograph (figure 7(b)) revealed the presence of only silver, zinc, and oxygen peaks, thereby validated the production of nanoparticles, a devoid of impurities.The weight percentages of oxygen (O), silver (Ag), and zinc (Zn) were observed to be 39.7%, 23.2%, and 37.1%, respectively.
The nature of crystals and quality of crystallinity for both samples is shown in TEM micrographs, figures 8(a)-(d).It was observed that the ZnO crystallites were larger as compared to Ag-doped ZnO crystallites.This finding supported the outcome of the XRD analysis.Figures 7(a) and (b) shows the TEM micrographs of ZnO and Ag-ZnO NPs, respectively, at a 100 nm scale.Whereas, figures 7(c) and (d) shows the formation of crystal planes for ZnO and Ag-ZnO NPs at 10 nm, respectively.Thus, the TEM micrographs show the formation of highly crystalline nanoparticles for both samples.
X-ray photoelectron spectroscopy (XPS) was used to examine the surface chemical composition of the synthesized ZnO and Ag-ZnO nanoparticles.Figures 9 and 10 shows the XPS scan spectra for the ZnO and Agdoped ZnO nanoparticles respectively.The primary elements on the samples' surfaces can be identified from their XPS spectra as zinc, oxygen, carbon, and silver.The presence of a low-intensity carbon C1s peak is most likely the result of impurities from the atmosphere adhering to the surface of the sample [50].To determine the atomic concentrations (tables 3 and 4) as well as to identify chemical bonds, the O 1s, Zn 2p, and Ag 3d were deconvoluted.In figure 9, symmetrical peaks at 1044.73 eV and 1021.28 eV, respectively, were displayed for the sample of pure ZnO that is assigned to Zn(2p 1/2 ) and Zn(2p 3/2 ).The splitting of Zn-2p states, which was brought on by the high spin-orbit coupling, started with an energy of about 23 eV.These findings implied the presence of Zn in 2+ oxidation state in both samples [52].We observed the Ag(3d) levels to describe the Ag element's chemical state, as shown in figure 10.The division at around 6 eV between the Ag(3d 3/2 ) 373.29 eV and Ag(3d 5/2 ) 367.28 eV peaks showed that the silver in the synthesized samples was metallic [33].Because Ag 2 O has the same binding energies as Ag-O, these peaks are likewise connected to Ag−O bonding [53].

Antibacterial activity
The result of antibacterial activity of nanoparticles against gram-positive bacteria: Staphylococcus aureus and Bacillus subtilis; gram-negative bacteria: Salmonella typhi were observed.Nanoparticles and antibiotics (ampicillin) show zone of inhibition against all the different pathogens as shown in figure 11.The inhibition zones (in mm) of varying sizes were obtained as mentioned in table 5 against Staphylococcus aureus and Bacillus subtilis, Salmonella typhi.The inhibition zones were measured around NPs and ampicillin in different well.
From table 5, it was observed that Ag-ZnO NPs indicated the maximum inhibition zone against Salmonella typhi (19 ± 0.53 mm) and minimum inhibition zone against Bacillus subtilis (15 ± 0.59 mm) whereas, ZnO NPs showed a maximum zone of inhibition against Staphylococcus aureus (15 ± 0.58 mm) and a minimum inhibition zone against Salmonella typhi (12 ± 0.49 mm).Expected inhibitory zones were observed for positive control as shown in figure 11(A).

Mechanism of antibacterial activity
As per the preceding discourse, the antimicrobial efficacy of ZnO NPs attributed to two plausible mechanisms, namely the generation of reactive oxygen species (ROS) and the production of Zn 2+ .Initially, the ZnO nanoparticles engaged with a membrane composed of proteins and lipids.Nanoparticles (NPs) underwent a reaction with proteins, leading to the formation of intricate structures comprising sulphur and phosphorous [54][55][56].The inactivation of membrane-bound enzymes and proteins was observed as a result of the interaction    between nanoparticles (NPs) and the cell membrane [56].ZnO NPs have been observed to exert an impact on the cellular membrane, leading to interference with the respiratory chains and subsequent inhibition of energy production [55].Moreover, the interaction between lipids and nanoparticles (NPs) altered the fluidity of the membrane, thereby modifying its structure and impeding its function through the induction of increased permeability and loss of membrane integrity.The extent of membrane penetration determined the cytoplasmic accessibility of nanoparticles, which subsequently interacted with sulphur-containing proteins and enzymes as well as phosphorous-containing DNA, ultimately leading to the induction of ROS [57].The Reactive Oxygen Species (ROS) encompassed the superoxide ions (O 2− ), hydroxyl ions (OH − ), and hydrogen peroxide (H 2 O 2 ).
Reactive oxygen species (ROS) effectively disrupted the chemical bonds that maintained the structural integrity of microorganisms, which ultimately resulted in cellular demise.The antimicrobial mechanism exhibited by nanoparticles is depicted schematically in figure 11(B).During the process, hydroxide ions (OH − ) accumulated on the cell membrane surface, leading to the degradation of the membrane.Conversely, H 2 O 2 traversed the cellular membrane and elicited detrimental effects on both the membrane structure and the macromolecules, such as DNA and proteins, residing within the membrane.It was observed that ZnO NPs exhibit highly effective antimicrobial properties.

Conclusion
In this study, we provided an easy, efficient, and eco-friendly process for the synthesis of ZnO and Ag-ZnO nanoparticles using Berberis aristata root extract as a reducing and stabilizing agent.Characterizations were carried out using FT-IR, FESEM, EDS, XPS, UV, and XRD techniques.The crystallite size decreased from 21.313 nm to 18.179 nm with the doping of Ag ions on ZnO NPs from the Scherrer method, whereas, the WH method also showed a decrease in crystallite size from 26.602 nm to 21.522 nm.The lattice strain was found to increase from 0.0031 to 0.0064 which revealed the occupation of Ag-ions in the crystal lattice of ZnO NPs.The FTIR spectra confirmed the formation of metal-oxygen bonds for both samples.The UV-visible spectroscopy showed a peak around 365 nm for ZnO, whereas, for Ag-ZnO two peaks were observed around 235 nm and 360 nm.Tauc's plot showed a minimal increase in bandgap from 3.01 eV to 3.02 eV with the Ag doping.The FESEM image showed the formation of agglomerated NPs with a spherical morphology whereas, TEM micrographs showed the formation of crystal structure.The EDX and XPS spectra showed the chemical makeup for both samples.For Ag, three peaks were observed which confirmed Ag ions in Ag3d 5/2 , Ag (bonded), and Ag3d 3/2 state.The antibacterial activity of ZnO NPs was highest against Staphylococcus aureus which was 15 ± 0.53 mm whereas, for Ag-ZnO NPs the highest activity was observed against Salmonella typhi i.e., 19 ± 0.53 mm.The prepared nanoparticles using Berberis aristata plant extract showed the formation of pure NPs that showed excellent antimicrobial activity.

Figure 1 .
Figure 1.Shows the preparation of root extract.
[35]0 ± 1.25 mg RUT/g, Carbohydrate (CAR) of 550.41 ± 1.30 mg D-glucose/100 g, Terpenoids (TER) of 104.34 ± 1.62 mg LIN/g, and Saponin (SAP) of 119.49± 1.35 mg DIO/g, as illustrated in figure 2. The presence of functional groups on the surface of ZnO and Ag-ZnO NPs has been verified through FTIR analysis.The synthesized NPs synthesized using green method exhibited a lack of agglomeration in the aqueous extract medium[35].

Table 2 .
Lattice parameters of green synthesized ZnO and Ag-doped ZnO nanoparticles.

Table 3 .
Atomic concentration of ZnO NPs calculated from XPS.

Table 4 .
Atomic concentration of Ag-ZnO NPs calculated from XPS.

Table 5 .
Inhibition zones of nanoparticles against different pathogenic strains; whereas, Ab represents Ag-ZnO NPs, Zn represents ZnO NPs.