RU2711559C1 - Method of producing colloidal solution of silver nanoparticles with plant leaves extracts - Google Patents

Abstract

FIELD: biochemistry.SUBSTANCE: present invention relates to biochemical methods for producing colloidal solutions of silver nanoparticles (Ag-NP) using plant leaves extracts. Described is a method of producing colloidal solution of silver nanoparticles with plant leaves extracts, involving soaking plant leaves in distilled water, filtering the solution to produce a plant extract, mixing it with an aqueous solution of silver nitrate, reducing silver ions with an extract to form Ag-NP silver nanoparticles, controlling size, shape and concentration of Ag-NP by optical spectrophotometry, transmission electron microscopy and laser light scattering, in which leaves of the evergreen tropical plant Murraya paniculata are used as leaves of the plant for preparing the vegetal extract, the aqueous solution of silver nitrate is taken in concentration of 1⋅10÷5⋅10mol/l, filtration is carried out using nuclear filters in the form of disks with diameter of up to 60 mm from material polyethylene terephthalate, with thickness of 9÷11 mcm, average pore size 0.22÷0.50 mcm, surface density of pores 10÷10cm, and then reducing silver ions with Murraya paniculata extract in air at room temperature under natural light and then filtering the above filter with the same characteristics to extract the formed silver nanoparticles from the obtained aqueous colloidal solution.EFFECT: simple technique of synthesis of colloidal solutions.1 cl, 5 dwg, 3 ex

Description

The present invention relates to biochemical methods for producing colloidal solutions of silver nanoparticles (Ag-NP) using plant leaf extracts and can be used in oncology, cosmetology and the food industry, in the development of biosensors, in microelectronics.

A known method of producing silver nanoparticles [Patent 2477172 C1 (RF) IPC B01J 19/00, B82B 3/00, C12N 15/63, B22F 9/24, 11/10/2011], characterized in that the cell culture of the plant before receiving callus extract previously they are transformed with the Agrobacterium tumefaciens GV3101 / pMP90RK / pPCV002 / 35S-LoSilAl-nos agrobacterial vector containing the silicatein gene LoSilAl, which provides the biosynthesis of monomorphic Ag-NPs, a callus extract is prepared by grinding callus with silver centrifuge with nitrite in water incubate solution on a shaker followed by centrifugation.

The disadvantage of this method is the presence of a preliminary stage of plant modification with the agrobacterial vector Agrobacterium tumefaciens GV3101 / pMP90RK / pPC V002 / 35S-LoSilAl-nos, which provides the synthesis of Ag-NPs. The nature of this drawback is due to the fact that plant growth is determined by the area of growth and climatic factors. Therefore, the stage of preliminary modification may depend on the development and growth conditions of the plant, which may have an undesirable effect on the size and shape of the formed Ag-NPs.

The closest in technical essence and the achieved result to the present invention is a method for the synthesis of silver, gold and zinc nanoparticles using plant seed extracts [Patent 9.428.399 B1 (USA) Int. Cl. C01G 9/02 (2006.01) A61K 33/30 (2006.01) A61K 33/38 (2006.01) A61K 33/24 (2006.01) C02F 1/72 (2006.01) B22F 9/24 (2006.01) B22F 1/00 (2006.01) C22B 7/00 (2006.01) С22В 3/00 (2006.01) С22В 9/20 (2006.01) С22В 9/34 (2006.01) C02F 101/10 (2006.01) C02F 101/12 (2006.01) US Cl. C01G 9/02 (2013.01), A61K 33/24 (2013.01), A61K 33/30 (2013.01), A61K 33/38 (2013.01), B22F 1/0018 (2013.01), B22F 1/0044 (2013.01), B22F 9 / 24 (2013.01), C02F 1/725 (2013.01), C22B 7/006 (2013.01), C22B 11/042 (2013.01), C22B 19/20 (2013.01), C22B 19/34 (2013.01), C02F 2101/10 (2013.01), C02F 2101/101 (2013.01), C02F 2101/12 (2013.01), C02F 2303/04 (2013.01), Y10S 977/773 (2013.01). Aug. 30, 2016], which in the case of producing Ag-NPs includes the following stages: about 15 mg of seeds of the Trigonella foenum-graecum plant (hay fenugreek is an annual bean family plant [Dudchenko L.G., Koziakov A.S., Krivenko V.V. // Spicy-aromatic and spicy-flavoring plants: Handbook / Edited by KM Sytnik. - Kiev: Naukova Dumka, 1989. - P. 172]) were soaked overnight in 30 ml of distilled water, then filtered the resulting solution to obtain an aqueous extract of the seeds of the plant Trigonella foenum-graecum, about 5 ml of the extract were added to 50 ml of an aqueous solution of silver nitrate and a concentration of 0.001 mol / liter, and then mixed for 15 minutes at 45 ° C; silver ions were reduced by Trigonella foenum-graecum seed extract, which leads to the formation of Ag NPs; control over the course of the recovery process was carried out by changing the color of the solution from colorless to dark brown; the shape and size of the resulting silver nanoparticles were controlled by transmission electron microscopy; the size distribution function of Ag NPs was determined by laser light scattering. The disadvantages of this method are: for the preparation of the extract it is necessary to use the seeds of the plant Trigonella foenum-graecum, collected in the maturity phase [Dudchenko L.G., Koziakov A.S., Krivenko V.V. // Spice-aromatic and spice-flavoring plants: Reference / Ed. ed. K.M. Sytnik. - Kiev: Naukova Dumka, 1989. - S. 172]. Depending on the growing conditions, the formation of seeds of the Trigonella foenum-graecum plant can occur several times a year, which can affect the availability of the substrate and its quality; the duration of the recovery of silver ions and the formation of Ag-NPs.

These disadvantages are due to the need to obtain silver nanoparticles with high antibacterial activity, low rate constants for the reduction of silver cations by reducing agents released from the seeds of the plant Trigonella foenum-graecum.

The technical result of the invention is to simplify the process of preparing a plant extract to obtain silver nanoparticles; simplification of the technology of "green" synthesis of colloidal solutions of silver nanoparticles with extracts of plant leaves.

This technical result is realized by a method for producing a colloidal solution of silver nanoparticles with plant leaf extracts, including soaking the plant leaves in distilled water, filtering the solution to obtain a plant extract, mixing it with an aqueous solution of silver nitrate, reducing silver ions with an extract to form silver nanoparticles Ag-NP control the size, shape and concentration of Ag-NPs using optical spectrophotometry, transmission electron microscopy and laser light scattering, When this as the leaves of a plant for the preparation of plant extract used evergreen leaves of the tropical plant Murraya paniculata, an aqueous solution of silver nitrate in concentrations take 1⋅10 ^-3 ÷ 5⋅10 ^-4 mol / l, filtering is carried out using nuclear filters in the form of disks with a diameter up to 60 mm from polyethylene terephthalate material, with a thickness of 9 ÷ 11 μm, an average pore size of 0.22 ÷ 0.50 μm, a surface pore density of 10 ⁶ ÷ 10 ⁸ cm ^-2 , and then silver ions are extracted with Murraya paniculata extract in air at room temperature temperature under action m natural light and a second filter is filtered as described above with the same characteristics to extract silver nanoparticles formed from the resulting aqueous colloidal solution.

Example No. 1.

The leaves of Murraya paniculata, an evergreen tropical plant collected in Myanmar, were used as a substrate for the synthesis of plant extract. After grinding, 2.5 g of a sample of scraps of dried leaves of Murraya paniculata was soaked at room temperature in 50 ml of distilled water, then filtered using a folded paper filter. The synthesis of Ag-NPs was carried out by adding 50 ml of an aqueous solution of AgNO ³ with a concentration of 5-10 ^-4 mol / L to 3 ml of an aqueous extract of Murraya paniculata and then storing the resulting reduction solution at room temperature, in air in the absence of natural light for 16 days . The formation of Ag-NPs in noticeable concentrations was not detected (Fig. 1, spectrum 3).

FIG. 1 Optical absorption spectra: (abscissa axis - wavelength, λ, nm, ordinate axis - optical density, OD) 1 - aqueous solution of 1 вод10 ^-3 mol / liter AgNO ₃ after storage in the dark in air at room temperature for 16 days; 2 - plant extract obtained by soaking 2.5 g of finely ground leaves of the plant Murraya paniculata in distilled water; 3 - a solution obtained by mixing 50 ml of an aqueous solution of 5-10 ^-4 mol / l AgNO ₃ with 3 ml of a plant-based aqueous extract of Murraya paniculata, after storage in the dark in air at room temperature for 16 days; 4 - reconstitution solution obtained by mixing 50 ml of an aqueous solution of 1-10 ^-3 mol / L AgNO ₃ with 3 ml of plant extract Murraya paniculata, after storage in natural light in air at room temperature for 2 days. Inset: approximation of the spectral shape of the plasmon resonance band of Ag-NPs in a newly synthesized colloidal solution by a set of Gaussian functions (I-III), IV - the result of the approximation.

Example No. 2. Murraya paniculata leaves collected in Myanmar were used as a substrate. After grinding, 1 g of a sample of leaf scrap Murraya paniculata was placed at room temperature in distilled water. The synthesis of Ag-NPs was carried out by adding 50 ml of an aqueous solution of AgNO ₃ with a concentration of 1 × 10 ^-3 mol / L to 3 ml of an aqueous extract of Murraya paniculata, and then storing the resulting reduction solution at room temperature in air under the influence of natural light for 2 days.

A discoloration of the reducing solution from light green to tan was detected. The appearance of a new band in the visible spectral region of 350-650 nm with a maximum at ~ 470 nm was observed in the optical absorption spectra (Fig. 1, spectrum 4). The sensitization of the silver ion reduction reaction is achieved due to the absorption of natural light by organic compounds of the coumarin class and other biologically active substances released into the solution from the leaves of the plant Murraya Paniculata [Aziz SSSA, Sukari MA, Rahmani M., Kitajima M., Aimi N., Ahpandi NJ // The Malaysian Journal of Analytical Sciences. - 2010. - V. 14, No. 1. - pp. 1-5]. After filtering the reducing solution through the pores of the nuclear filter in the form of disks with a diameter of 59 mm from polyethylene terephthalate material, 9 μm thick, average pore size 0.22 ÷ 0.30 μm, surface pore density 1⋅10 ⁶ ÷ 1⋅10 ⁷ cm ^-2 , by scanning electron microscopy, a precipitate was detected in the form of an Ag-NP layer distributed over the filter surface (Fig. 2).

FIG. 2 Images of a precipitate from silver nanoparticles synthesized in the volume of a reducing solution obtained by mixing 50 ml of an aqueous solution of 10 ^-3 mol / liter AgNO ₃ with 3 ml of a plant-based aqueous extract of Murraya paniculata, after storage under natural light in air at room temperature in 2 days, on the surface of a nuclear filter based on a polyethylene terephthalate film after filtering the recovery solution through micropores

Therefore, the nature of the absorption band with a maximum of ~ 470 nm can be associated with plasmon resonance of silver nanoparticles formed as a result of photosensitized reduction of silver ions by reducing agents (presumably coumarins and their derivatives) [Aziz SSSA, M. Sukari, M. Rahmani, Kitajima M., Aimi N, Ahpandi NJ // The Malaysian Journal of Analytical Sciences. - 2010. - V. 14, No. 1. - pp. 1-5]), released into the distilled water from the leaves of the plant Murraya paniculata.

By the methods of transmission electron microscopy and laser light scattering, the formation of numerous Ag-NPs (Figs. 3-5) was predominantly spherical and oval in size from 5 nm to several microns (Fig. 3). The maximum size distribution function of Ag-NPs corresponded to 25-30 nm (Figs. 4, 5).

FIG. 3 Image of silver nanoparticles synthesized in the volume of a reducing solution obtained by mixing 50 ml of an aqueous solution of 1-10 ^-3 mol / L AgNO ₃ with 3 ml of a plant extract of Murraya paniculata, after storage under natural light in air at room temperature for 2 days recorded by transmission electron microscopy. The measurement conditions are shown in the figure.

FIG. 4 Images of newly synthesized silver nanoparticles in the volume of a reducing solution obtained by mixing 50 ml of an aqueous solution of 1-10 ^-3 mol / L AgNO ₃ with 3 ml of a plant extract of Murraya paniculata, after storage under natural light in air at room temperature for 2 days recorded during measurements by laser light scattering.

FIG. 5 The function of size distribution of silver nanoparticles recorded by laser light scattering obtained in the volume of a reducing solution obtained by mixing 50 ml of an aqueous solution of 1-10 ^-3 mol / L AgNO ₃ with 3 ml of a plant-based aqueous extract of Murraya paniculata, after storage under natural conditions lighting in air at room temperature for 2 days, before and after passing through a nuclear filter based on a polyethylene terephthalate film with an average micropore size of 0.22 microns.

Example No. 3. The dried leaves of Murraya paniculata were used as a substrate for the synthesis of plant extract. After grinding, 2.5 g of a sample of leaf scrap Murraya paniculata was placed at room temperature in distilled water, placed in a water bath to speed up the extraction process. The obtained extract was filtered through nuclear filters in the form of disks with a diameter of 60 mm from polyethylene terephthalate material, 11 μm thick, with an average pore size of 0.5 μm, and a pore surface density of 1 × 10 ⁸ cm ^-2 . The synthesis of Ag-NPs was carried out by adding 50 ml of an aqueous solution of AgNO ₃ (concentration of 1-10 ^-3 mol / l) to 3 ml of an aqueous extract of Murraya paniculata, and then storing the resulting reduction solution at room temperature in air under the influence of natural light for 2 days. A color change to dark brown was detected, and a new absorption band in the visible spectrum with a maximum of ~ 470 nm was detected by optical spectroscopy. After secondary filtration of the reducing solution through the pores of a nuclear filter with the same characteristics, a precipitate was found in the form of an Ag-NP layer distributed over the filter surface.

Thus, the inventive method for producing colloidal solutions of Ag-NP refers to the class of so-called "Green" nanotechnology, which is currently being considered as an environmentally friendly and cheap biochemical alternative to traditional physical and chemical methods for the synthesis of silver nanoparticles [Jackson TS, Patani V.O., Ekpa D.E. // Advances in Nanoparticles. - 2017. - V. 6. - pp. 93-102]. Carrying out the process in air at room temperature under natural light conditions allows one to accelerate the processes of cation reduction and the formation of Ag NPs in comparison with the implementation of the considered stage in the dark.

The inventive method allows to solve the problem and achieve the expected technical result, namely: to simplify and reduce the cost of the process of obtaining colloidal solutions of silver nanoparticles by replacing expensive and not always available seeds with other parts of plants - leaves of evergreen tropical plants growing in natural conditions, cheap, not requiring special care, available at any time. The proposed method is waste-free, based on the use of natural light, which allows to reduce the duration of the entire process, as well as significantly reduce energy costs, excluding, for example, microwave processing [Patent No. 2618270 C1 (RF) IPC B22F 9/24 (2006.01), C01G 5 / 00 (2006.01), B01J 13/00 (2006.01), B82B 3/00 (2006.01), B82Y 30/00 (2011.01), B82Y 5/00 (2011.01), A61K 33/38 (2006.01), 10/07/2015] .

Claims (1)

A method of obtaining a colloidal solution of silver nanoparticles with plant leaf extracts, including soaking the plant leaves in distilled water, filtering the solution to obtain a plant extract, mixing it with an aqueous solution of silver nitrate, reducing silver ions with an extract to form silver nanoparticles of Ag-NP, size control, shape and Ag-NP concentration using optical spectrophotometry, transmission electron microscopy and laser light scattering, characterized in that as the leaves For the preparation of plant extract, leaves of the evergreen tropical plant Murraya paniculata are used, an aqueous solution of silver nitrate is taken in a concentration of 1⋅10 ^-3 ÷ 5⋅10 ^-4 mol / l, the filtering is carried out using a nuclear filter in the form of disks with a diameter of up to 60 mm from the material polyethylene terephthalate with a thickness of 9 ÷ 11 μm, an average pore size of 0.22 ÷ 0.50 μm, a surface pore density of 10 ⁶ ÷ 10 ⁸ cm ^-2 , and then silver ions are extracted with Murraya paniculata extract in air at room temperature under the influence of natural light and toricity filter is filtered as described above with the same characteristics to extract silver nanoparticles formed from the resulting aqueous colloidal solution.

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