Green Synthesis and Characterization of Silver Nanoparticles from Thymus Vulgaris Leaf Extract

Abstract

In this present study thymus vulgaris leaf were collected from home town(Nilgiris). The fresh leaves are taken in the round bottom flask and refluxed for around 1 hour until the aqueous colour changes. The extract was collected and 1mM silver nitrate solution was added to it after the addition of silver nitrate the pale yellow extract changes its color to dark brown. The change in colour indicates the reduction of particle size in the thymus vulgaris leaf extract. The characterization of green synthesis of silver nanoparticles were done by using U-vis, XRD, FTIR, SEM and SEM EDAX. This studies explains the physical characterization of the silver nano particles produced.

Introduction

I. INTRODUCTION

Nanotechnology is the act of manipulating compounds at very tiny scales at the levels of atoms and molecules. Commonly  nanotechnology explain  their  structures  and size between1-100  nanometer in  one dimension, and involves the  development  of  materials or devices within that size[1].  General  nanometer is compared  one millionth of a millimeter approximately 100,000 times smaller than the diameter of a human hair.  The broad and inter disciplinary area of research and development activity in Nanoscience and Nanotechnology has been growing very fast worldwide in the last  few years[2]. A nanoparticle is defined as nano object with  all three external dimension in the nanoscale, whose longest and the shortest do not differ significantly[3]. A nano fiber has two external dimension in the nanoscale, with nanotubes being hollow nanofibres and nano rods being solid nanofibers[4]. Nanostructured materials are often categorized by what phases of matter the contain.a nanocomposite is a solid containing at least one physically or chemaically distinct region,or collection of regions, having at least one dimension in the nanoscale[5]. A nanocrystalline material has a significant fraction of crystal grains in the nanoscale[6]. The nano particle  size ,shape and surface  of the morphology were play pivotal role in controlling the chemical, physical, , optical, and electronic properties of these nanoscopic materials[7]. Looking at the nanoparticles, silver nanoparticles are alluring particularly for antimicrobial cleansing. Consequently, a few plants have been examined in the combination in silver nanoparticles. This load of examinations are confined to plants of earthly beginning, however not with beach front plants. Subsequently, the current review was made to combination the antimicrobial silver nanoparticles by utilizing leaf and callus concentrates of the beach front Thymus Vulgaris plant[8].

II. MATERIALS AND METHODS

A. Plant Extract  Preparation

The fresh leaves of  Thymus vulgaris were collected from Medical Plant Development Area (MPDA) which is  located in  Cinchona village, Doddabetta post, Ooty, The Nilgiris , Tamil Nadu, India. The collected fresh leaves were washed several times with distilled water until the dust particles are removed. The leaves of  Thymus vulgaris  were measured around 20 gram and cut into small pieces then it was taken in   500ml of round bottom flask. A mixture of leaf along with 200ml of distilled water was made to reflux around 2 hours.Initially the extract is green color. After refluxing the extract color changes to pale yellow until extract color  changes to pale yellow. The extract was collected and filtered using Whats Mann No.1 filter paper. After filtering,the extract was stored in room temperature for further process.

B. Green Synthesis of Silver Nanoparticles

Silver Nitrate (AgNO3) was purchased from Spectrum Reagents and Chemical Pvt.Ltd Edayar, Cochin, India. 100ml of Thymus vulgaris  leaf extract and 200ml of 0.01mM solution was added. The  mixture was stirred around 20-30 minutes until the color changed from pale yellow to dark brown and was allowed to rest for precipitate.  Then the precipitate was washed with distilled water twice to remove soluble impurities and was collected and centrifuged around 1000 rpm for about 30 minutes.

The obtained precipitate was taken in the petri dish glass plate  and it was shade dried until the moisture was removed. The powder samples were then collected for further characterization techniques.

C. Characterization of Silver Nanoparticles

All the characterization studies were done in SAIF cochin. Spectra were recorded with     UV Vis NIR spectro photometer  agilent cary 5000  in the region 200nm to 3000nm DRS(Diffuse Intergrating Sphere diameter 150mm angle of incidence 80) [9].The X-Ray Diffraction(XRD) measurement was performed on X-ray diffractometer(Bruker D8 Advance) operated at 30 Kv and 100 MA and  spectrum was recorder by cukα radition with wave length of 1.506 A0  in the range 200-800nm[10].The surface morphology and size  were  characterized  by Scanning Electron Microscope (SEM)( Joel 6390LA)[11].  Energy Dispersive X-ray (EDX)  oxford XMX N operated at 0.5 kV to  30 kV  at magnification 300000 and EDX  resolution  at 136 Ev[12]. FTIR analysis was using thermo Nicolet Avtar )370 range between 4000cm-1 to400cm-1[13].TGA studies was recorded by TGA-DTA Hitachi STA7000 instrument  up to 1500 deg [14].

III. RESULTS AND DISCUSSION

A. UV-VIS ANALYSIS RESULT

UV–visible spectroscopy is mostly  used to analyse the  techniques for structural characterization of nanoparticles[15]. The biosynthesized silver nanoparticles  were measured by UV–visible spectroscopy at different time intervals to study the change in light absorption and increase in intensity. The UV spectra of Thymus vulgaris  silver nanoparticles synthesized displayed a strong broad absorbtion peak around 350nm due to the formation of AgNps as shown in Fig(1).

This peak corresponded to the surface plasmon resonance of the synthesized AgNps. After 48 hours  the prepared mixture of AgNps is stored in  the dark room the mixture of solution change into pale  yellow to dark brown  colour[16].

B. XRD ANALYSIS RESULT

The XRD analysis was carried out to determine the known phase of the silver nanoparticles. XRD pattern of the dried synthesized AgNPS Nano particles prepared by Thymus vulgaris  leaf extract.

                                             D= K λ ? βcosθ nm

The above given is the scherrer formula.Where D – is the mean size of the ordered crystalline domains­­ –is a dimensionless shape factor, with a value also to unity. The shape factor has a typical value of about 0.9 λ –is the X-ray wavelengthβ –is the line broadening at half the maximum intensity (FWHM)θ –is the Bragg angle[17][18]. The obtained data was matched with the Joint Committee on Powder Diffraction Standards (JCPDS) file No.030921. The XRD spectrm  fig(2) showed  five  distinct diffraction  peaks at 32.118 ,38.007,44.177 and 64.344 77.242which are indexed the (111),(200),(220), (311) of the fcc silver nanoparticles[19][20].The average grain crystalline size of AgNps was prepared from Thymus vulgaris  was calculated  to be 13nm[21].

C.  SEM Analysis Result

The surface morphology of the AgNps  was studied using Scanning Electron Microscope analysis. SEM image exhibited that the biosynthesized silver nanoparticles were mostly  in spherical  shapes. The size of the nanoparticles were within the range of 1-50nm.It is also noticed that the nanoparticles are in direct contact with each other .The capping agent noticed in the nanoparticles gives the stabilization for the particle. The caping agent may be due to the sediments in the leaf extract. [22].

  D. EDX Analysis Result

EDX technique is used to determine the elemental analysis and quantitative determination of available minerals in the nanoparticles. EDX spectra of the synthesized silver nanoparticles from Thymus Vulgaris leaf extract confirmed the presence of elemental silver in the sample [23]. The EDX profile of the AgNps prepared using thymus vulgaris extract showed the presence of  silver(fig4),additional elements also observed C,O,P,S,Cl,K,Ca,Ag [24]. Quantitative analysis proved 3% silver contents in the examined samples.The mass % of silver in the sample is 34.65 and atom % is 6.39[25].

E.  FTIR Analysis Result

Fouier transform infrared spectroscopy analysis method uses infrared light to scan test samples and observe chemical properties and characterization of the Thymus vulgaris  leaf extract and the functional groups of present silver nanoparticles[26]. The FTIR spectrum of stabilized silver nanoparticles is shown in (fig 5). FTIR showed  absorption   3451.92cm-1,  1621.85 cm-1,1494.54 cm-1,1248.24 cm-1,1166.52 cm-1,1058.01  and cm-1,511.51 cm-1  as shown in (Fig 5). In this spectra  the peak  3451.92cm-1  absorption corresponds to the strong stretching vibrations of OH functional group[25]. 1621.85 cm-1 cm−1 due to the stretching vibration of C=C[27]. 1494.54 cm-1   corresponds  to C-Cl stretching mode and it indicated alkyl halides groups.[28] The peak absorbed in1248.24 cm-1  and 1058.01 cm-1 is  remarked to C–N stretching possible  due to the presence of amines group[29]. 1166.52 cm-1  corresponds to  C-N stretching alcohols[30].

     G.  Antimicrobial Studies

1. Antibacterial

The antibacterial activity of  biosynthesized  silver nanoparticles using Thymus vulgaris  silver nanoparticles ,ciprofloxacin, was studied against Gram-positive (S. aureus and B.subtilis ) and Gram-negative K.pneumoniae and E. coli) bacteria using the agar well diffusion assay, and the zone of  inhibition was tabulated in Table 1. The synthesized AgNPs showed  good  efficient antibacterial activity against for both Gram-negative and Gram-positive bacteria. The silver nanoparticles synthesized by Thymus vulgaris  silver nanoparticles  showed the maximum zone of inhibition  around 14 mm for S.aureus for and 13 nm for B.subtiliswhich were followed by K.pneumoniae (5 mm) and E.coli (8 mm). When compared with the standard ciprofloxacin the synthesized   AgNps  shows 72 % of inhibition against E. coli, 38% against K.pneumoniae, 46% against B.subtilis and 42% against S. aureus.  The positive control

2. Antifungal                                                                                                             

In the agar disc diffusion method, the concentrations of greener synthesized Thymus vulgaris silver nanoparticles and  inhibition of  ketoconazole is shown in the fig 7. Inhibition zone around discs incorporated with nanoparticles. The synthesized silver nanoparticles (positive control) showed significant inhibition of fungi. A broad spectrum of antifungal activity of silver nanoparticles was observed against a wide range of wood-degrading fungi. Moreover, the biosynthesized silver nanoparticles exhibited strong antifungal activity against the  Aspergillus niger(10mm), Aspergillus flavus(10mm), Candida albicans(7mm). Penicillium sps(6mm) were showed in table 2

IV. ACKNOWLEDGMENT

The authors sincerely  thank SAIF ,STIC, cochin university for recording powder XRD and SEM,SEM- EDX spectrum, FTIR spectrum  and UV-VIS spectrum. sincere gratitude to my guide Dr. S. Venkateshwari Assistant professor, Department of physics, Government Arts College   Udhagamandalam Tamil Nadu.

Conclusion

In this study the silver nanoparticles were successfully synthesized using the extract of Thymus vulgaris leaf for the first time. The biosynthesized AgNPs were characterized using UV-Vis, FTIR, SEM, EDX, and XRD,TGA have confirmed characteristic features of Thymus vulgaris silver nanoparticles. Furthermore Thymus vulgaris silver nanoparticles were made without any impurities. The results were within approximate ranges of each other and the values reported in previous studies. The UV-Vis analysis confirmed the AgNPs at 320 nm. The average size of the AgNPs prepared was calculated in the range of 14 nm using XRD pattern. The spherical shape and plate surface shape of AgNPs was observed by SEM image. Energy dispersive x-ray (EDX) shows the ED spectrum of the synthesized silver nanoparticles strong silver signal along with weak chlorine (Cl), carbon(C), oxygen (O) peak was observed. The FTIR analysis related the presence of various functional groups. Here in we reported eco-friendly and low cost process for synthesis of AgNPs. The plant source may act as capping agents which control the size and capping agents which control the size and shape of the silver nanoparticles.

References

[1] V. Gopinath, D. MubarakAli, S. Priyadarshini, N. M. Priyadharsshini, N. Thajuddin, and P. Velusamy, “Biosynthesis of silver nanoparticles from Tribulus terrestris and its antimicrobial activity: A novel biological approach,” Colloids Surfaces B Biointerfaces, vol. 96, pp. 69–74, Aug. 2012, doi: 10.1016/j.colsurfb.2012.03.023. [2] P. Pourali, B. Yahyaei, and S. Afsharnezhad, “Bio-Synthesis of Gold Nanoparticles by Fusarium oxysporum and Assessment of Their Conjugation Possibility with Two Types of ?-Lactam Antibiotics without Any Additional Linkers,” Microbiol. (Russian Fed., vol. 87, no. 2, pp. 229–237, 2018, doi: 10.1134/S0026261718020108. [3] S. Jebril, R. Khanfir Ben Jenana, and C. Dridi, “Green synthesis of silver nanoparticles using Melia azedarach leaf extract and their antifungal activities: In vitro and in vivo,” Mater. Chem. Phys., vol. 248, no. December 2019, 2020, doi: 10.1016/j.matchemphys.2020.122898. [4] J. R. Nakkala, R. Mata, A. K. Gupta, and S. R. Sadras, “Biological activities of green silver nanoparticles synthesized with Acorous calamus rhizome extract,” Eur. J. Med. Chem., vol. 85, pp. 784–794, 2014, doi: 10.1016/j.ejmech.2014.08.024. [5] Dellavalle, “Antifungal Activity of Medicinal Plant Extracts Against,” Chil. J. Agric. Res., vol. 71, no. June, pp. 231–239, 2016. [6] S. Anees Ahmad et al., “Bactericidal activity of silver nanoparticles: A mechanistic review,” Mater. Sci. Energy Technol., vol. 3, pp. 756–769, 2020, doi: 10.1016/j.mset.2020.09.002. [7] R. S. Patil, M. R. Kokate, and S. S. Kolekar, “Bioinspired synthesis of highly stabilized silver nanoparticles using Ocimum tenuiflorum leaf extract and their antibacterial activity,” Spectrochim. Acta - Part A Mol. Biomol. Spectrosc., vol. 91, pp. 234–238, 2012, doi: 10.1016/j.saa.2012.02.009. [8] A. Nabikhan, K. Kandasamy, A. Raj, and N. M. Alikunhi, “Synthesis of antimicrobial silver nanoparticles by callus and leaf extracts from saltmarsh plant, Sesuvium portulacastrum L.,” Nabikhan, Asmathunisha, Kathiresan Kandasamy, Anburaj Raj, Nabeel M. Alikunhi. 2010. “Synthesis Antimicrob. Silver Nanoparticles by Callus Leaf Extr. from Saltmarsh Plant, Sesuvium Portulacastrum L.” Colloids Surfaces B Biointerfaces , vol. 79, no. 2, pp. 488–493, 2010, doi: 10.1016/j.colsurfb.2010.05.018. [9] P. Balashanmugam and P. T. Kalaichelvan, “Biosynthesis characterization of silver nanoparticles using Cassia roxburghii DC. aqueous extract, and coated on cotton cloth for effective antibacterial activity,” Int. J. Nanomedicine, vol. 10, pp. 87–97, 2015, doi: 10.2147/IJN.S79984. [10] A. Info, “Green Synthesis of Silver Nanoparticles Using Cymbopogan Citratus (Dc) Stapf. Extract and Its Antibacterial Activity,” Aust. J. Basic Appl. Sci., vol. 8, no. March, pp. 324–331, 2014. [11] M. del Carmen Travieso Novelles et al., “Biosynthesis of fluorescent silver nanoparticles from Leea coccinea leaves and their antibacterial potentialities against Xanthomonas phaseoli pv phaseoli,” Bioresour. Bioprocess., vol. 8, no. 1, 2021, doi: 10.1186/s40643-020-00354-2. [12] S. Priyadarshini, V. Gopinath, N. Meera Priyadharsshini, D. MubarakAli, and P. Velusamy, “Synthesis of anisotropic silver nanoparticles using novel strain, Bacillus flexus and its biomedical application,” Colloids Surfaces B Biointerfaces, vol. 102, pp. 232–237, 2013, doi: 10.1016/j.colsurfb.2012.08.018. [13] K. Ali, B. Ahmed, S. Dwivedi, Q. Saquib, A. A. Al-Khedhairy, and J. Musarrat, “Microwave accelerated green synthesis of stable silver nanoparticles with Eucalyptus globulus leaf extract and their antibacterial and antibiofilm activity on clinical isolates,” PLoS One, vol. 10, no. 7, pp. 1–20, 2015, doi: 10.1371/journal.pone.0131178. [14] L. David and B. Moldovan, “Green synthesis of biogenic silver nanoparticles for efficient catalytic removal of harmful organic dyes,” Nanomaterials, vol. 10, no. 2, 2020, doi: 10.3390/nano10020202. [15] N. Ravendran and P. M. Chou, “Silver nanoparticle synthesis , UV-Vis spectroscopy to find particle size and measure resistance of colloidal solution Silver nanoparticle synthesis , UV-Vis spectroscopy to find particle size and measure resistance of colloidal solution,” 2020, doi: 10.1088/1742-6596/1706/1/012020. [16] P. Nancy, J. James, S. Valluvadasan, and R. A. V Kumar, “Nano-Structures & Nano-Objects Laser – plasma driven green synthesis of size controlled silver nanoparticles in ambient liquid,” Nano-Structures & Nano-Objects, vol. 16, pp. 337–347, 2018, doi: 10.1016/j.nanoso.2018.09.006. [17] R. Geethalakshmi and D. V. L. Sarada, “Synthesis of plant-mediated silver nanoparticles using Trianthema decandra extract and evaluation of their anti microbial activities,” Int. J. Eng. Sci. Technol., vol. 2, no. 5, pp. 970–975, 2010. [18] S. Ghosh et al., “Synthesis of silver nanoparticles using Dioscorea bulbifera tuber extract and evaluation of its synergistic potential in combination with antimicrobial agents,” Int. J. Nanomedicine, vol. 7, pp. 483–496, 2012. [19] M. M. Juibari, S. Abbasalizadeh, G. S. Jouzani, and M. Noruzi, “Intensified biosynthesis of silver nanoparticles using a native extremophilic Ureibacillus thermosphaericus strain,” Mater. Lett., vol. 65, no. 6, pp. 1014–1017, 2011, doi: 10.1016/j.matlet.2010.12.056. [20] A. Lateef, I. A. Adelere, E. B. Gueguim-Kana, T. B. Asafa, and L. S. Beukes, “Green synthesis of silver nanoparticles using keratinase obtained from a strain of Bacillus safensis LAU 13,” Int. Nano Lett., vol. 5, no. 1, pp. 29–35, 2015, doi: 10.1007/s40089-014-0133-4. [21] K. Mallikarjuna et al., “GREEN SYNTHESIS OF SILVER NANOPARTICLES USING OCIMUM LEAF EXTRACT AND THEIR CHARACTERIZATION.” [22] A. Raj and R. Lawerence, “Green synthesis and charcterization of ZnO nanoparticles from leafs extracts of Rosa indica and its antibacterial activity,” Rasayan J. Chem., vol. 11, no. 3, pp. 1339–1348, 2018, doi: 10.31788/RJC.2018.1132009. [23] R. W. Raut, V. D. Mendhulkar, and S. B. Kashid, “Photosensitized synthesis of silver nanoparticles using Withania somnifera leaf powder and silver nitrate,” J. Photochem. Photobiol. B Biol., vol. 132, pp. 45–55, 2014, doi: 10.1016/j.jphotobiol.2014.02.001. [24] A. Saravanakumar, M. M. Peng, M. Ganesh, J. Jayaprakash, M. Mohankumar, and H. T. Jang, “Low-cost and eco-friendly green synthesis of silver nanoparticles using Prunus japonica (Rosaceae) leaf extract and their antibacterial, antioxidant properties,” Artif. Cells, Nanomedicine Biotechnol., vol. 45, no. 6, pp. 1165–1171, 2017, doi: 10.1080/21691401.2016.1203795. [25] P. P. N. Vijay Kumar, S. V. N. Pammi, P. Kollu, K. V. V. Satyanarayana, and U. Shameem, “Green synthesis and characterization of silver nanoparticles using Boerhaavia diffusa plant extract and their anti bacterial activity,” Ind. Crops Prod., vol. 52, pp. 562–566, 2014, doi: 10.1016/j.indcrop.2013.10.050. [26] A. Journal, C. T. Pyrolysis, P. Optimization, F. Quality, E. View, and S. Padmanaban, “Synthesis of silver nanoparticles using Lantana camara fruit extract and its Academic Sciences Asian Journal of Pharmaceutical and Clinical Research,” no. January 2012, pp. 1–6, 2017. [27] H. Zhang et al., “Biosorption and bioreduction of diamine silver complex by Corynebacterium,” J. Chem. Technol. Biotechnol., vol. 80, no. 3, pp. 285–290, 2005, doi: 10.1002/jctb.1191. [28] B. Ajitha, Y. A. Kumar, and P. S. Reddy, “Spectrochimica Acta Part A?: Molecular and Biomolecular Spectroscopy Biosynthesis of silver nanoparticles using Plectranthus amboinicus leaf extract and its antimicrobial activity,” Spectrochim. ACTA PART A Mol. Biomol. Spectrosc., vol. 128, pp. 257–262, 2014, doi: 10.1016/j.saa.2014.02.105. [29] A. R. Allafchian, S. A. H. Jalali, S. S. Hashemi, and M. R. Vahabi, “Green synthesis of silver nanoparticles using phlomis leaf extract and investigation of their antibacterial activity,” J. Nanostructure Chem., vol. 6, no. 2, pp. 129–135, 2016, doi: 10.1007/s40097-016-0187-0. [30] K. J. Rao and S. Paria, “Author ’ s personal copy Green synthesis of silver nanoparticles from aqueous Aegle marmelos leaf extract.”

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Copyright © 2022 P. Wilson, S. Venkateshwari. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.