MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION THESIS FOOD TECHNOLOGY EFFECTS OF CAPPING AGENT CONCENTRATION AND REACTION TIME ON ANTIMICROBIAL ACTIVITIES OF COPPER NANOPARTICLES (CUNPs) SUPERVISOR: TRINH KHANH SON STUDENT: TRAN THI BAO CHAU DONG THAO DUYEN SKL 0 0 9 1 5 7 Ho Chi Minh City, August, 2022 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT Thesis code 2022-18116005 EFFECTS OF CAPPING AGENT CONCENTRATION AND REACTION TIME ON ANTIMICROBIAL ACTIVITIES OF COPPER NANOPARTICLES (CUNPs) TRAN THI BAO CHAU Student ID: 18116005 DONG THAO DUYEN 18116007 Major: FOOD TECHNOLOGY Supervisor: TRINH KHANH SON, ASSOC. Ho Chi Minh City, August 2022 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING GRADUATION PROJECT Thesis code 2022-18116005 EFFECTS OF CAPPING AGENT CONCENTRATION AND REACTION TIME ON ANTIMICROBIAL ACTIVITIES OF COPPER NANOPARTICLES (CUNPs) TRAN THI BAO CHAU Student ID: 18116005 DONG THAO DUYEN 18116007 Major: FOOD TECHNOLOGY Supervisor: TRINH KHANH SON, ASSOC. Ho Chi Minh City, August 2022 DECLARATION As a result, we declare that all content presented in this graduation thesis has been carried out by us, including instructors and students. The research content is based on the requirements, design, and guidelines and is validated by the instructor.
The entire content of the graduation thesis has been checked against plagiarism using Turnitin software, ensuring no more than 30% duplication. We certify that regulations have correctly and fully cited the contents referenced in the graduation thesis. ___, August 2022 Signature i ACKNOWLEDGEMENT To complete this graduation thesis, first and foremost, we would like to thank the Faculty of Chemical and Food Technology, University of Technical Education, Ho Chi Minh City, for creating all conditions for equipment and facilities to help us complete the thesis. Moreover, we would like to thank our adored supervisor, Trinh Khanh Son, Assoc.
This paper could have never been accomplished without their assistance and dedicated involvement in every process step. We are extremely grateful to them for supporting and understanding us during the past time. We are also grateful to the 2017 and 2019 students who supported us in the research process. With limited experience and conditions, implementing the thesis inevitably has shortcomings.
We look forward to receiving the attention and comments of teachers to improve our report. Our team sincerely thanks. ii iii iv v vi vii viii ix x xi xii xiii TABLE OF CONTENTS Chapter 1: INTRODUCTION. Limits and scope of the study.
The scientific and practical significance of the topic. Layout of the report. Overview of nanotechnology. The concept of nanotechnology.
Classification of nanomaterials. Applications of nanotechnology in food. Overview of copper nanoparticles. Introduction to copper nanoparticles.
Methods for synthesizing copper nanoparticles. Antibacterial mechanism of copper nanoparticles. The fungus Colletotrichum gloeosporioides. 12 Chapter 3: MATERIALS AND RESEARCH METHODS.
Synthesis method for CuNPs. Characteristic measurement methods of CuNPs. UV-VIS spectroscopy. Energy-dispersive X-ray spectroscopy (EDS) analysis.
X-ray diffraction spectroscopy (XRD) analysis. Scanning Electron Microscope (SEM) analysis. Transmission electron microscopy (TEM) analysis. Zeta potential (ZP) measurement.
Antimicrobial activity evaluation methods. Method to determine the resistance to Escherichia coli. Method for determining resistance to mold Colletotrichum gloeosporioides. Data analysis method .21 Chapter 4: RESULTS AND DISCUSSION.
Characterization of CuNPs. X-ray diffraction of CuNPs (XRD). SEM, TEM and DLS. Effect of capping agent (starch) concentration on antibacterial ability of nano solution…………………………….
The antifungal ability of CuNPs on Colletotrichum gloeosporioides strain .40 Chapter 5: CONCLUSIONS AND SUGGESTIONS .50 xv LIST OF FIGURES Fig. Groups of nanomaterials [17]. Applications of nanotechnology in all areas of food science [21]. Methods for synthesizing copper nanoparticles [31].
Schematic illustration of the antibacterial mechanism of CuNPs [39]. Nanoparticles are covalently bonded to the capping agent[40]. Types of capping agents based on the structure of the molecular chain [42]. Anthracnose cycle in tropical fruit trees [50].
Anthracnose symptoms on some tropical fruit trees. CuNPs synthesis process. UV-vis spectra of CuNPs according to different starch concentrations (%w/v) at reaction times (A) t20, (B) t30……………………………………………………………………………. EDS of CuNPs and composition of the elements of the CuNPs are measured from the EDS.
XRD plot of samples t20 S1,15; t20 S2,29; t20 S3,06; t30 S0,76; t30 S1,91 and t30 S2,6. The angled octahedron (b, c, d) and the angled cube (e) are morphological intermediates of the octahedron (a) and the cube (f) [71]. SEM image of samples t20 S1,15; t20 S2,29; t20 S3,06; t30 S0,76; t30 S1,91 and t30 S2,67. Size distribution of 100 particles from SEM images of samples t20 S1,15; t20 S2,29; t20 S3,06; t30 S0,76; t30 S1,91 and t30 S2,67.
TEM image and sample size distribution (A) t20 S2,29 và (B) t30 S0,76. The average particle size of CuNPs according to different starch concentrations (%w/v) at reaction time t20 and t30 by DLS method. Zeta potential plot of CuNPs against different starch concentrations (%w/v) at reaction times t20 and t30.coli according to different starch concentrations (%w/v) at reaction times (A) t20 and (B) t30 .coli colonies after 48 h of plate pouring at reaction times t20 and t30. Colony diameter of C.
gloeosporioides according to incubation time at different concentrations of CuNPs at reaction times (A) t20 and (B) t30. The inhibitory effect on C. gloeosporioides concerning incubation time at different concentrations of CuPs at reaction times (A) t20 and (B) t30. gloeosporioides by observation time after 3, 5 and 7 days.
Results of inhibiting the growth of C. gloeosporioides on apples after seven days of observation.42 xvi LIST OF TABLES Table 2. The symptoms as well as the pathogenic mechanisms that are present in some E. Coding convention for copper nanoparticles samples in research………………….
Zeta potential and the stability of the colloidal [55]. The average crystal size of nanoparticles. The intensity ratio between (111) and (200) diffraction peaks of nanoparticles. Average size of nanoparticles from SEM images.
Average size of nanoparticles from TEM images .31 xvii LIST OF EQUATIONS nλ = 2dsinθ (3. 18 log reduced = log A1 – log A2 (3. 20 𝐑−𝐫 % Inhibition of growth = 100 (3. 21 𝐑 xviii LIST OF ABBREVIATIONS %w/v Weight/volume percent C.gloeosporioides Colletotrichum gloeosporioides CFU Colony forming units CuNPs Copper Nanoparticles DLS Dynamic Light Scattering E.coli Escherichia coli EDS Energy-dispersive X-ray spectroscopy NB Nutrient broth ppm Parts per million S-CuNPs Starch capped Copper Nanoparticles SEM Scanning Electron Microscope TEM Transmission Electron Microscopy UV - Vis Ultraviolet Visible XRD X-Ray diffraction ZP Zeta potential xix ABSTRACT In this study, we focused on evaluating the antibacterial potential of copper(I) oxide nanoparticles.
CuNPs were prepared by chemical reduction method with copper sulfate anhydrous as precursor and D - glucose as reducing agent in the presence of soluble starch capping agent. The characteristic properties of CuNPs were demonstrated through various measurements such as X-ray diffraction (XRD), UV-vis spectroscopy, scanning electron microscopy (SEM), DLS particle size distribution, Zeta potential, and transmission electron microscopy (TEM). The results indicated that our synthesized copper(I) oxide nano samples have high purity. Resistance to bacteria and molds had also been observed.
Overall, S-CuNPS completely inhibited the growth of Escherichia coli and Colletotrichum gloeosporioides at a concentration of 50ppm and a concentration of 500ppm for molds with a soluble starch content of 0.764 % (%w/v) with reaction time was 30 minutes. Furthermore, for the in vivo antifungal assays on mangoes, the coatings containing CuNPs inhibited fungal growth. Overall, based on the above results, S-CuNPs might be applied as an agent to control microorganisms that form pathogen biofilms. Keywords: S-CuNPs, characteristic, antibacterial ability, Escherichia coli, Colletotrichum gloeosporioides xx Chapter 1: INTRODUCTION 1.
Rationale Nanotechnology has had tremendous and valuable applications in electronics, energy, medicine, cosmetics, and especially biomedicine, thanks to its ability to help humans intervene at the nanometer scale, where nanomaterials exhibit many unique and exciting properties. The synthesis of nano by two chemical and physical methods has been widely studied; however, the cost of nano synthesis by some of the above methods is often very high, and the use of toxic materials in different stages is rugged synthetic that affects human health and is not friendly to the environment [1]. Therefore, there is an urgent need to research and develop green biological methods to synthesize NPs. In addition, in nanotechnology, many studies have focused on synthesizing two metals, gold and silver, but there are few studies on synthesizing CuNPs, especially green synthesis.
With cheap synthesis cost, ease of use, large-scale application, and outstanding properties, especially antibacterial properties similar to precious metals, CuNPs have been and are being researched by manufacturers and researchers. Not only that, in solutions, bare nanoparticles are thermoelectrically unstable and tend to aggregate, losing their specific properties. Therefore, investigating different types of coatings for nano synthesis is also of interest to researchers. Typically, the research of [2] has successfully synthesized copper (I) oxide nanoparticles with the smallest particle size of 222 ± 13 nm, with the use of reducing agent, glucose, and polyvinyl alcohol (PVA) encapsulation showed the results that copper (I) oxide nanoparticles had the highest ability to kill E.
coli at a concentration of 160 ppm with a treatment time of 1 hour and a pH value of 8. Recently, [3] demonstrated antibacterial and antifungal activity of copper oxide/carbon (CuO/C) nanocomposites against Pseudomonas aeruginosa, Escherichia coli, Klebsiella neumonia, Staphylococcus aureus, Candida albicans, and Aspergillus niger. On the other hand, following the progress of science and technology, finding more optimal preservation methods for agricultural products such as fruits is receiving much attention, including the research direction of biopolymer films, the most prominent being edible films. With those mentioned superior antibacterial properties of CuNPs, along with the constant increase of pathogenic bacteria that threaten the lives of humans and other organisms, the research and application of CuNPs in life is significant and is a new and urgent direction.
For the above reasons, we decided to choose the research topic with the research content “Effects of capping agent concentration and reaction time on antimicrobial activities of copper nanoparticles (CuNPs)” 1. Thesis objects In this study, copper(I) oxide nanoparticles were synthesized by chemical reduction, using copper sulfate anhydrous as a precursor, D-Glucose as a reducing agent, and starch as a capping agent. We focused on investigating the factors affecting the antibacterial ability of copper nanoparticle solutions, such as reaction time, the concentration of capping agent (starch), and storage conditions. From there, find the conditions for synthesizing nano copper with the most optimal antibacterial ability.
Limits and scope of the study CuNPs were prepared by chemical reduction method with copper sulfate anhydrous as precursor and D - glucose as reducing agent in the presence of soluble starch capping agent. We investigated the influence of reaction time, encapsulation concentration, and nano solution storage conditions to form the optimal synthesis formula and process to obtain the nano solution with the best antibacterial activity. The bacteria used were Escherichia coli and the mold Colletotrichum gloeosporioides. Research content In this study, we conducted the following: - Synthesis of copper(I) oxide nanofluids - Investigate the effect of starch capping agent concentration on the antibacterial ability of copper(I) oxide nanofluids.
- The effect of copper concentration on antimicrobial resistance was investigated. - Evaluation of the size, distribution, and morphology of copper nanoparticles by TEM, SEM, and Zeta potential. The scientific and practical significance of the topic Nanotechnology has promoted development in all fields, especially biomedical, energy, environment, information technology, military,etc. Nano copper(I) oxide with good antibacterial ability is a potential material for food preservation.
Applying active film to preserve food products such as meat, fish, fruit, etc., prolongs the storage time and minimizes pathogenic microorganisms' growth.
