Bio-synthesis of Triangular and Hexagonal Gold Nanoparticles using Palm Oil Fronds’ Extracts at Room Temperature. Adamu Ibrahim Usmana*, Azlan Abdul Aziza and Osama Abu Noqtab a
b
School of Physics University Sains Malaysia, 11800, Pulau Pinang, Malaysia Institutes for Research in Molecular Medicine, USM, 11800, Pulau Pinang, Malaysia *
[email protected]
Abstract Development of bio-reduction techniques for nanoparticles (NPs) synthesis in medical application remains a challenge to numerous researchers. This work reports a novel technique for the synthesis of triangular and hexagonal gold nanoparticles (AuNP) using palm oil fronds’ (POFs) extracts. The functional groups in the POFs’ extracts operate as a persuasive capping and reducing agent to growth AuNPs. The prepared AuNPs were characterized using UV-vis spectrophotometry, FTIR spectroscopy, dynamic light scattering (DLS), energy filtered transmission electron microscopy (EFTEM), and x-ray diffraction (XRD. The analysis of FTIR validates the coating of alkynes and phenolic composites on the AuNPs. This shows a feasible function of biomolecules for efficient stabilization of the AuNPs. Energy-filtered transmission electron microscopy (EFTEM) clearly show the triangular and hexagonal shapes of the prepared AuNPs. The XRD patterns display the peaks of fcc crystal structures at (111), (200), (220), (311) and (222), with average particle sizes of 66.7 and 79.02 nm for 1% and 5% POFs extracts concentrations respectively at room temperature. While at 120oC the average particles size recorded for 1% and 5% of POFs extract concentrations were 32.17 nm and 45.66 nm respectively, and the reaction completed in less than 2 minutes. The prepared NPs could be potentially applied in biomedical application, due to their excellent stability and refine morphology without agglomeration.
Keywords: biosynthesis, gold nanoparticles, oil palm frond, triangular, stability Introduction The biosynthesis of noble metallic nanoparticles (NPs) for medical application is one of the active fields of research (Zhang, 2015). Gold nanoparticles (AuNPs) have widely fascinated so many researchers, due to their potential applications in optical properties (Reddy et al., 2016), electrical conductivity (Hakamada et al., 2016), and catalysis (Liu at el., 2016). AuNPs were promptly synthesized and displayed high chemical and thermal stability (Noruzi, 2015). Various techniques have been reported for the production of different shape AuNPs (Tran et al., 2016; Reischl et al., 2014; Mahyari et al., 2016). Hopwever, Such techniques are not defined as biodegradable and are depend on the reduction of metallic ion solutions with traditional capping or reducing agents like Hexadecyltrimethylammonium bromide and sodium dodecyl sulphate (Ling et al., 2012; Noruzi, 2015). The non-biodegradable nature of the techniques restricted their usage in food and medical fields (Das et al., 2010). Majority of these compounds are noxious, and their utilization is a risk to human life due to little measure of some reagents that stay free and non-receptive in the mixture. The concept of green NPs production was completly achieved by Raveendran and his group in 2003, whereby silver nanoparticles was synthesized using b-D-glucose and starch as reducing and capping agent respectevely. A purely green process for nanoparticle production ought to be from three angles: standard solvent, eco-friendly reducing agent, and nontoxic stabilizing agent. As such no other
chemical is needed in the production process (Raveendran et al., 2003). Though, sometimes additional chemicals were added to investigate various physiological characteristics of the NPs such as hydroxylamine (Siti et al., 2013) for controlling particles size and the distribution of particles. Recently, the primary focus of researchers is the improvement of efficient green techniques for the growth of AuNPs (Sharma et al., 2015). Green synthesis of AuNPs using plants such as herbal Ferulago Angulata aqueous extract (Alizadeh et al., 2017), tevia rebaudiana leaf extracts (Sadeghi et al., 2015), Garcinia mangostana Fruit Peels (Xin et al., 2016), thiolated poly (ethylene glycol) (Lee et al., 2016), Dillenia indica (Sett et al., 2016), Artocarpus Lakoocha fruit and its leaves, and Eriobotrya Japonica leaves (Sharma et al., 2017) and isolated strain Trichosporon montevideense (Shen et al., 2016) were reported to serve as an effective stabilizing agent in the biosynthesis of AuNPs successfully. Likewise, various plant extracts were utilized in the biosynthesis of gold and silver NPs simultaneously like gum extract of Prunus armeniaca (Islam et al., 2016). However, most of the techniques used previously are time consuming and required high temperature. Consequently, different varieties of plant do exist such as palm oil fronds (POFs) with proven capabilities in various application (Salma 2014). The POFs is a waste material available in abundance in Asia and some African countries This study examined the use of palm oil fronds (POFs) extracts as the reducing agent as well as stabilizing agent to synthesize AuNP. This provides a solution for utilizing toxic chemicals to produce AuNPs. Best on our knowledge, this is the first time the synthesis of AuNPs with POFs extracts will be reported. The prepared NPs were characterized via UV–vis spectrophotometry, dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), energy-filtered transmission electron microscopy (EFTEM), and X-ray diffraction (XRD). The prepared NPs show excellent stability, refine morphology without agglomeration and exhibit temperature subordinate as the reaction completed in 20 minutes at room temperature and less than 2 minutes at 120 oC. Material and method Tetrachloroauric acid (HAuCl4 •3H2O) was obtained from Sigma-Aldrich Chemicals and utilized without alteration. Freshly prepared doubled distilled water (DDW) was used throughout the experiment. Preparation of Oil Palm Fronds Aqueous Extract Palm oil fronds (POFs) were collected from Palmco Holding Bhd Penang Malaysia. The POFs were washed with DDW and oven-dried for 6 hours at 150 oC. The POFs aqueous extract was used as reducing and capping agents. The extract was prepared by immersing 1% and 5% (w/w) of POFs extracts in 100 ml of DDW and left overnight. The mixture was boiled for 10 minutes at 80 °C and the extracts were filtered using Wartman No. 1 filter paper. Subsequently, the filtrate was stored at 4 °C for further use. Synthesis of Gold Nanoparticles 10ml of the extracts were mixed with 100 ml of 0.01% (w/w) of the gold precursor. The reaction were stirred by magnetic stirrer at ambient temperature. The effect of POFs extracts concentration on the prepared AuNPs was investigated using 1% and 5% quantity of the
extracts. The mixture was stirred at 350 rpm for 20 minutes. Within the first 2 minutes at 120 o C change in color was observed, this indicated the formation of AuNPs. Characterization of Gold Nanoparticles The prepared AuNPs were characterized via UV–vis spectra for surface plasmon resonance (SPR) measurements with Shimadzu in the range of 400 –700 nm. FTIR spectroscopy Perkin Elmer System 2000 was used to study the kind of ligand in the extracts that protects the assynthesized AuNPs from agglomeration in the range of 600 – 4000 cm−1. D8 ADVANCE BRUKER was used to performed XRD experiment with Cu K radiation (λ = 0.154 Å) regulated at the potential difference of 40kV and current of 40 mA in the range of 30 – 90. The colloidal gold was centrifuged (14,500 rpm, 25 ◦C) for 10 min, washed thrice with DDW, then dried in an oven and subjected to XRD and FTIR analysis. Zeta potential together with Mean particle size and their distribution was investigated using DLS method. The morphology of the prepared AuNPs was analysed using EFTEM Zeiss Libra 120. Results and Discussion Physio chemical characterization of AuNPs The manifestation of the ruby red color confirmed the production of AuNPs, the reduction of Au3+ ions from HAuC4.3H2O to Au0 by POFs extracts lead to the formation of AuNPs. The ruby red color of AuNPs was imputed by inducing the interacting electromagnetic field due to collective oscillation of electrons in metallic NPs (Mulvaney, 1996), and production of AuNPs was affirmed via UV–vis absorption spectra (Fugure 1). No significant difference in the peak absorbance for S1 (1% of POFs extracts) and S2 (5% of POFs extracts) at room temperature was observed. Similar pattern and almost same peak with a value of 567 nm and 565.5 nm were recorded for S1 and S2 respectively (Figure 1a). A significant difference was observed between the absorbance peaks of the set of two experiments performed at 120 oC, with a distinct pattern and different peak values at 540.5 nm and 533.5 nm for S3(1% of POFs extracts) and S4 (%% of POFs extracts) respectively (Fugure 1b). This indicated that temperature affects the formation of AuNPs at different concentration due to its correlation with absorbance peaks and high electrolyte concentration of the functional groups.
Figure 1 UV-visible spectra of gold nanoparticles (AuNPs) at various conditions (a) at room temperature, indicated that there is no significant difference in the absorption (b) at 120 oC, indicated that a significant difference existed due to the variation of extracts concentration.
FTIR Spectral Analysis FTIR spectrum analysed the POFs extracts and prepared AuNPs. The FTIR spectral analysis before and after the bioreduction reveals the action of the functional groups in the stabilization of the prepared AuNPs. The FTIR spectral results for both POFs extracts and prepared AuNPs (Fugure 2) shows absorption band at 670.92 cm-1, 1978.1 cm-1, 2109.35 cm-1, 2163.57 cm-1, 2337 cm-1 and 3326.53 cm-1; and 1207.8 cm-1, 1637.83 cm-1, 2113.74 cm-1, 2163.14 cm-1, 2340.7 cm-1, 2358.82 cm-1 and 3307.231 cm-1 respectively. The absorption peaks at 3326.53 cm-1 and 3307.231 cm-1 are attributed due to –NH stretching vibration, –OH (phenol) functional ligand, and secondary amines (protein) in the POFs extracts. It is noted that the peak fluctuates from higher peak (3326.53 cm-1) to the lower peak (3307.231 cm-1) wavelength. This resulted in the reduction of Au3+ to Au0 and the peak at 2337 cm-1 also extended and split into 2358.82 cm-1 and 2340.7 cm-1 as shown in the AuNPs spectral (Fugure 2). This indicate the formation of AuNPs (Dhas et al., 2012; Dhas, Kumar et al., 2014). with these finding, we can conclude that functional groups –OH, -NH and amines are the factors responsible for causing the stabilization of AuNPs due to POFs extracts (He et al., 2008). The functional groups protect the AuNPs from agglomeration and lead to the formation of NPs with the good shape as revealed by the EFTEM analysis.
Figure 2 FTIR spectra of oil palm fronds (POFs) extracts (A) before the reaction and (B) after the reaction reveals the action of functional phenolic composites upon reduction and stabilization of nanoparticles
DLS and EFTEM Measurement Particles size and normal distribution of the prepared AuNPs was successfully measured using DLS method. Average particle size of 66.75 nm (Fugure 3a) and 79.02 nm (Fugure 3b) for S1 and S2 was measured respectively at room temperature. Consequently, at 120 oC 32.17 nm (Fugure 3c) and 45.66 nm (Fugure 3d) were recorded for S3 and S4 respectively. It was noted that at elevated temperature, the sizes of the NPs reduced to almost half of its size. This implies the increase in temperature decreases the particle size (Fayaz at el., 2009). The morphology of the prepared AuNPs obtained from the EFTEM results indicates that the NPs are poly-dispersed with triangular, hexagonal and spherical shapes (Fugure 4a & 4b) for S1 and S2 at room temperatures respectively (Noruzi at el., 2011). Meanwhile, Figure 4c and Figure 4d shows the morphology of the prepared AuNPs at 120oC.
Figure 3 Particles size distribution of prepared gold nanoparticle (AuNPs) under various condition (a) at 25oC using 1% of the palm oil fronds (POFS) extracts, (b) at 25oC using 5% of POFS extracts (c) at 120oC with 1% of POFS extracts and (d) at 120oC with 5% of POFS extracts.
XRD Analysis The XRD pattern reveals that the prepared AuNPs are crystalline. The miller indices (111), (200), (220), (311) and (222) corresponding to the reflection peaks emerged at 38.2o, 44.4 o, 64.6o, 77.5 o and 81.7o respectively (Figure 4). These features indicate the characteristics of face-centered cubic (fcc) structure. The formation of the NPs is confirmed due to broadening of the peaks (Narayanan & Sakthivel, 2008). There are no other peaks show up which signifies high purity of the AuNPs synthesized using POFs extracts.
Figure 4 EFTEM images of gold nanoparticles produce using 1% of palm oil fronds (POFS) extracts (a) at room temperature and (c) at 120 oC, while 5% of the (POFs) extracts was recorded (b) at room temperature (d) at 120 o C
Figure 5 XRD spectra for gold nanoparticles (AuNPs) produced using palm oil fronds (POFs) extracts and the intensity peak of the reference peak observed shows the characteristic of the nanocrystal. The reflection of the angle at 38.2o coincide with Au 111 was very intense due to the sequence of the Au.
Stability of Prepared AuNPs
Furthermore, the four-experimental setup exhibits negative zeta potential for the prepared AuNPs. The values of the zeta potential were found to be -15.8, -17.4, -17.1, and -13.2 (mV) for S1, S2, S3, and S4 respectively. This revealed the stability of the prepared NPs. The negative esteem shows stability in the growth of NPs, and its evasion of the agglomeration of the NPs (Raja et al., 2017). The results revealed that temperature influences the stability of the NPs’ growth at the same concentration. When 5% of POFs extracts was used, the zeta potential obtained at room temperature is -17.4 mV (Figure 6a). However, when the temperature was elevated to 120 oC, the zeta potential value increased to -13.2 mV (Fugure 6b). Consequently, when 1 % was used, the zeta potential decreased from -15.8 mV at room temperature (Fugure 6c) to -17.1 mV (Fugure 6d) at 120oC. Observably, this contradicted the previous results and this may be due to poor distribution quality of the results S3. The distribution is not manifested like in the case of S4. The negative potential might be due to the stabilizing or capping responses of bio agents present in the extracts of palm oil fronds. The schoimetric reaction of the synthesized NPs observed through the oxidation of hydroxyl to carbonel groups is similarly described as shown in the equation below: ℎ
𝐴𝑢𝐶𝑙4− + 3R– OH → 𝐴𝑢0 + 2𝑅 = 𝑂𝐻 + 3𝐻 + + 4𝐶𝑙¯
1
Figure 6 zeta potential analysis of the as-synthesized AuNPs at different concentration and temperature (a) at 1% of POFE and at 25oC (b) at 5% of POFE and at 25oC (c) at 1% of POFE and at 120oC (d) at 5% of POFE and at 120oC
Conclusion An eco-friendly and environmental banning approach for the production of AuNPs by the POFs extracts was successfully synthesized. The AuNPs were characterized by UV-vis spectroscopy, FTIR, DLS, EFTEM, and XRD. The size of AuNPs decreased with increasing temperature and POFs extracts concentration. Triangular and hexagonal shapes were revealed for the prepared AuNPs via EFTEM. The XRD analysis defined the fcc structure with the basic plane (111). This developed method provides another opportunity to explore POFs extract as potential reducing agent for the synthesis of AuNPs in large quantity. The presence of different compounds in the fronds of POFs extracts demonstrates the properties of both eco-friendly reducing agent and nontoxic stabilizing agent. No established study has been reported with the usage of POFs extracts for the production AuNPs. The prepared NPs can be potentially applied in biomedical application. Acknowledgement The authors thoroughly acknowledged Ministry of Higher Education (MOHE), Federal University Kashere and Universiti Sains Malaysia through FRGS Grant PSPFIZIK 1000000003375 for the full support which makes this vital research viable and useful. REFERENCES ALIZADEH, A., PARSAFAR, S. & KHODAEI, M. 2017. Biosynthesis of spherical and highly stable gold nanoparticles using Ferulago Angulata aqueous extract: dual role of extract. Materials Research Express, 4, 035029 DAS, R. K., BORTHAKUR, B. B. & BORA, U. 2010. Green synthesis of gold nanoparticles using ethanolic leaf extract of Centella asiatica. Materials Letters, 64, 1445-1447. DHAS, T. S., KUMAR, V. G., ABRAHAM, L. S., KARTHICK, V. & GOVINDARAJU, K. 2012. Sargassum myriocystum mediated biosynthesis of gold nanoparticles. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 99, 97-101. DHAS, T. S., KUMAR, V. G., KARTHICK, V., ANGEL, K. J. & GOVINDARAJU, K. 2014. Facile synthesis of silver chloride nanoparticles using marine alga and its antibacterial efficacy. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 120, 416-420. FAYAZ, A. M., BALAJI, K., KALAICHELVAN, P. & VENKATESAN, R. 2009. Fungal based synthesis of silver nanoparticles—an effect of temperature on the size of particles. Colloids and Surfaces B: Biointerfaces, 74, 123-126. HAKAMADA, M., KATO, N. & MABUCHI, M. 2016. Electrical resistivity of nanoporous gold modified with thiol self-assembled monolayers. Applied Surface Science, 387, 1088-1092. HE, S., ZHANG, Y., GUO, Z. & GU, N. 2008. Biological synthesis of gold nanowires using extract of Rhodopseudomonas capsulata. Biotechnology Progress, 24, 476-480. ISLAM, N. U., AMIN, R., SHAHID, M. & AMIN, M. 2016. Gummy gold and silver nanoparticles of apricot (Prunus armeniaca) confer high stability and biological activity. Arabian Journal of Chemistry. LEE, M.-J., LIM, S.-H., HA, J.-M. & CHOI, S.-M. 2016. Green Synthesis of High Purity Mesoporous Gold Sponges Using Self-Assembly of Gold Nanoparticles Induced by Thiolated Poly (ethylene glycol). Langmuir. LING, T. P., RAZAK, K. A., AZIZ, A. A., MASROM, A., NOORSAL, K., MUHAMAD, M. & YOU, A. Properties of gold nanoparticles synthesized in aqueous solution. AIP Conference Proceedings 2nd, 2012. AIP, 219-224. LIU, J., LIU, G., LIU, C., LI, W. & WANG, F. 2016. Nano-sized mesoporous sodium iron hydroxyphosphate supported gold: an effective catalyst for the oxidation of sulfides. Catalysis Science & Technology, 6, 2055-2059.
MAHYARI, F. A., TOHIDI, M. & SAFAVI, A. 2016. Synthesis of gold nanoflowers using deep eutectic solvent with high surface enhanced Raman scattering properties. Materials Research Express, 3, 095006 MULVANEY, P. 1996. Surface plasmon spectroscopy of nanosized metal particles. Langmuir, 12, 788800. NARAYANAN, K. B. & SAKTHIVEL, N. 2008. Coriander leaf mediated biosynthesis of gold nanoparticles. Materials Letters, 62, 4588-4590. NORUZI, M. 2015. Biosynthesis of gold nanoparticles using plant extracts. Bioprocess and Biosystems Engineering, 38, 1-14. NORUZI, M., ZARE, D., KHOSHNEVISAN, K. & DAVOODI, D. 2011. Rapid green synthesis of gold nanoparticles using Rosa hybrida petal extract at room temperature. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 79, 1461-1465. RAJA, S., RAMESH, V. & THIVAHARAN, V. 2017. Green biosynthesis of silver nanoparticles using Calliandra haematocephala leaf extract, their antibacterial activity and hydrogen peroxide sensing capability. Arabian Journal of Chemistry, 10, 253-261. RAVEENDRAN, P., FU, J. & WALLEN, S. L. 2003. Completely “green” synthesis and stabilization of metal nanoparticles. Journal of the American Chemical Society, 125, 13940-13941. REDDY, H., GULER, U., KILDISHEV, A. V., BOLTASSEVA, A. & SHALAEV, V. M. 2016. Temperaturedependent optical properties of gold thin films. arXiv preprint arXiv:1604.00064. REISCHL, B., KURONEN, A. & NORDLUND, K. 2014. Nanoindentation of gold nanorods with an atomic force microscope. Materials Research Express, 1, 045042 SADEGHI, B., MOHAMMADZADEH, M. & BABAKHANI, B. 2015. Green synthesis of gold nanoparticles using Stevia rebaudiana leaf extracts: Characterization and their stability. Journal of Photochemistry and Photobiology B: Biology, 148, 101-106. SETT, A., GADEWAR, M., SHARMA, P., DEKA, M. & BORA, U. 2016. Green synthesis of gold nanoparticles using aqueous extract of Dillenia indica. Advances in Natural Sciences: Nanoscience and Nanotechnology, 7, 025005. SHARMA, A., DHIMAN, N., SINGH, B. P. & GATHANIA, A. K. 2014. Green synthesis of gold nanoparticles using extracts of Artocarpus Lakoocha fruit and its leaves, and Eriobotrya Japonica leaves. Materials Research Express, 1, 10 SHARMA, D., KANCHI, S. & BISETTY, K. 2015. Biogenic synthesis of nanoparticles: a review. Arabian Journal of Chemistry. SHEN, W., QU, Y., PEI, X., ZHANG, X., MA, Q., ZHANG, Z., LI, S. & ZHOU, J. 2016. Green synthesis of gold nanoparticles by a newly isolated strain Trichosporon montevideense for catalytic hydrogenation of nitroaromatics. Biotechnology letters, 1-6. SHI, Y., HUANG, J.-K., JIN, L., HSU, Y.-T., YU, S. F., LI, L.-J. & YANG, H. Y. 2013. Selective decoration of Au nanoparticles on monolayer MoS2 single crystals. Scientific reports, 3. SITI, R. M., KHAIRUNISAK, A. R., AZIZ, A. A. & NOORDIN, R. Study on controlled size, shape and dispersity of gold nanoparticles (AuNPs) synthesized via seeded-growth technique for immunoassay labeling. Advanced Materials Research, 2012. Trans Tech Publ, 504-509. SITI, R. M., KHAIRUNISAK, A. R., AZLAN, A. A. & NOORDIN, R. Green synthesis of 10 nm gold nanoparticles via seeded-growth method and its conjugation properties on lateral flow immunoassay. Advanced Materials Research, 2013. Trans Tech Publ, 8-12. TRAN, M., DEPENNING, R., TURNER, M. AND PADALKAR, S., 2016. Effect of citrate ratio and temperature on gold nanoparticle size and morphology. Materials Research Express, 3(10), p.105027.
WANG, X. & BUNKERS, G. J. 2000. Potent heterologous antifungal proteins from cheeseweed (Malva parviflora). Biochemical and biophysical research communications, 279, 669-673. XIN LEE, K., SHAMELI, K., MIYAKE, M., KUWANO, N., BT AHMAD KHAIRUDIN, N. B., BT MOHAMAD, S. E. & YEW, Y. P. 2016. Green Synthesis of Gold Nanoparticles Using Aqueous Extract of Garcinia mangostana Fruit Peels. Journal of Nanomaterials, 2016.
ZHANG, X. 2015. Gold nanoparticles: recent advances in the biomedical applications. Cell biochemistry and biophysics, 72, 771-775.
