Prof. Charitha Jayaruk Thambiliyagodage

Person:
Prof. Charitha Jayaruk Thambiliyagodage

ORCID

https://orcid.org/0000-0003-0906-4441

Google Scholar

https://scholar.google.com/citations?user=kdc5vsQAAAAJ

Name

Prof. Charitha Jayaruk Thambiliyagodage

Biography

Jayaruk is a graduate of the University of Colombo. He pursued his PhD in Chemistry from The University of Alabama, USA. He has specialized in Materials, Analytical and Physical Chemistry. Currently, he is working as an Assistant Professor at the Department of Applied Sciences, SLIIT. He is the coordinator of the BSc Biotechnology degree programme. He has been awarded the chartered chemist designation by the Institute of Chemistry, Ceylon. He supervises Postgraduate students at the University of Colombo and the University of Kelaniya and supervises undergraduate students at the Institute of Chemistry. He is interested in doing research on using nanomaterials in water purification and as antimicrobial reagents. Further, he is interested in researching on algae and plant materials for their pharmaceutical and cosmeceutical activities. He has specialized in many instruments like Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD), X-Ray Photoelectron Spectrometer (XPS), Gas chromatograph-Mass spectrometer (GC-MS), Raman Spectrometer, FT-IR spectrometer, UV-Visible Spectrophotometer, Brunauer-Emmett-Teller (BET) surface area analyzer etc. He is interested in practical-based science education and believes in uplifting the research culture among upcoming scientists in the country.

Research Interests

Application of nanomaterials for water purification Novel nanomaterials incorporated cosmeceuticals and pharmaceuticals Natural material based neutraceuticals Alternative energy sources Novel packaging materials Environmental Chemistry

Organizational Units

Organizational Unit

Faculty of Humanities & Sciences

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Now showing 1 - 10 of 12

Embargo
Kinetic study of in vitro release of curcumin from chitosan biopolymer and the evaluation of biological efficacy
(Elsevier B.V., 2024-09) Wijayawardana, S; Thambiliyagodage, C; Jayanetti, M
Sustained release of curcumin from the polymeric carrier system chitosan, a natural biopolymer material derived from chitin originated from natural shrimp shell waste, was studied. Six kinetic models, zero order, first order, Korsmeyer–Peppas (KP), Peppas – Sahlin (PS), Higuchi, and Hixson–Crowell, were applied to study the drug release kinetics. The release mechanism of the drug from the curcumin-chitosan composite was evaluated by changing the pH, ionic strength of the release media, and drug concentration. KP and PS models were selected among the studied models to investigate the drug release mechanism from the chitosan biopolymer based on the R2 values (R2 > 0.99). The model constants m in the PS model and n in the KP model stand for the case II relaxation and Fickian diffusion contribution, respectively. The n being < 0.43 in the KP model suggests that the Fickian diffusion governs the drug release. Furthermore, there is a noticeable difference between the values obtained for model parameters m and n in the PS and KP models, indicating that Case II relaxation and Fickian diffusion play crucial roles in the curcumin release mechanism from chitosan. Polymer relaxation has been proven to play a predominant role in releasing curcumin from the composite at lower ionic strengths and higher pH values. Anti-inflammatory activity was tested using the egg-albumin denaturation assay, and the diphenyl-2-picrylhydrazyl assay was carried out to determine the antioxidant activity of the composite. The composite material showed IC50 values of 0.29 mg/ mL and 1.08 mg/ mL for anti-inflammatory and anti-oxidant activities, respectively. The drug composite has shown antibacterial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus, which are highly effective against S.aureus. The resulting inhibition zones for S.aureus were 13.34 ± 0.34 mm, 16.34 ± 0.60 mm, and 13.34 ± 0.73 mm for 5, 10, and 20 mg/ml concentrations, respectively. The drug composite’s minimum inhibitory concentration/ minimum bactericidal concentration ratio for S.aureus, K. pneumoniae, and P.aeruginosa was greater than 4, suggesting that they cause bacteriostatic effects.
Open Access
Fabrication of r-GO/GO/α-Fe2O3/Fe2TiO5 Nanocomposite Using Natural Ilmenite and Graphite for Efficient Photocatalysis in Visible Light
(MDPI, 2023-01) Usgodaarachchi, L; Jayanetti, M; Thambiliyagodage, C; Liyanaarachchi, H; Vigneswaran, S
Hematite (α-Fe2O3) and pseudobrookite (Fe2TiO5) suffer from poor charge transport and a high recombination effect under visible light irradiation. This study investigates the design and production of a 2D graphene-like r-GO/GO coupled α-Fe2O3/Fe2TiO5 heterojunction composite with better charge separation. It uses a simple sonochemical and hydrothermal approach followed by L-ascorbic acid chemical reduction pathway. The advantageous band offset of the α-Fe2O3/Fe2TiO5 (TF) nanocomposite between α-Fe2O3 and Fe2TiO5 forms a Type-II heterojunction at the Fe2O3/Fe2TiO5 interface, which efficiently promotes electron-hole separation. Importantly, very corrosive acid leachate resulting from the hydrochloric acid leaching of ilmenite sand, was successfully exploited to fabricate α-Fe2O3/Fe2TiO5 heterojunction. In this paper, a straightforward synthesis strategy was employed to create 2D graphene-like reduced graphene oxide (r-GO) from Ceylon graphite. The two-step process comprises oxidation of graphite to graphene oxide (GO) using the improved Hummer’s method, followed by controlled reduction of GO to r-GO using L-ascorbic acid. Before the reduction of GO to the r-GO, the surface of TF heterojunction was coupled with GO and was allowed for the controlled L-ascorbic acid reduction to yield r-GO/GO/α-Fe2O3/Fe2TiO5 nanocomposite. Under visible light illumination, the photocatalytic performance of the 30% GO/TF loaded composite material greatly improved (1240 Wcm−2). Field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) examined the morphological characteristics of fabricated composites. X-ray photoelectron spectroscopy (XPS), Raman, X-ray diffraction (XRD), X-ray fluorescence (XRF), and diffuse reflectance spectroscopy (DRS) served to analyze the structural features of the produced composites. © 2022 by the authors.
Open Access
Recent Advances in Chitosan-Based Applications—A Review
(MDPI, 2023-03-03) Thambiliyagodage, C; Jayanetti, M; Mendis, A; Ekanayake, G; Liyanaarachchi, H; Liyanaarachchi, S
Chitosan derived from chitin has gathered much interest as a biopolymer due to its known and possible broad applications. Chitin is a nitrogen-enriched polymer abundantly present in the exoskeletons of arthropods, cell walls of fungi, green algae, and microorganisms, radulae and beaks of molluscs and cephalopods, etc. Chitosan is a promising candidate for a wide variety of applications due to its macromolecular structure and its unique biological and physiological properties, including solubility, biocompatibility, biodegradability, and reactivity. Chitosan and its derivatives have been known to be applicable in medicine, pharmaceuticals, food, cosmetics, agriculture, the textile and paper industries, the energy industry, and industrial sustainability. More specifically, their use in drug delivery, dentistry, ophthalmology, wound dressing, cell encapsulation, bioimaging, tissue engineering, food packaging, gelling and coating, food additives and preservatives, active biopolymeric nanofilms, nutraceuticals, skin and hair care, preventing abiotic stress in flora, increasing water availability in plants, controlled release fertilizers, dye-sensitised solar cells, wastewater and sludge treatment, and metal extraction. The merits and demerits associated with the use of chitosan derivatives in the above applications are elucidated, and finally, the key challenges and future perspectives are discussed in detail.
Open Access
Efficient Visible-Light Photocatalysis and Antibacterial Activity of TiO2-Fe3C-Fe-Fe3O4/Graphitic Carbon Composites Fabricated by Catalytic Graphitization of Sucrose Using Natural Ilmenite
(American Chemical Society, 2022-07-26) Thambiliyagodage, C; Usgodaarachchi, L; Jayanetti, M; Liyanaarachchi, C; Kandanapitiye, M; Vigneswaran, S
Dyes in wastewater are a serious problem that needs to be resolved. Adsorption coupled photocatalysis is an innovative technique used to remove dyes from contaminated water. Novel composites of TiO2-Fe3C-Fe-Fe3O4dispersed on graphitic carbon were fabricated using natural ilmenite sand as the source of iron and titanium, and sucrose as the carbon source, which were available at no cost. Synthesized composites were characterized by X-ray diffractometry (XRD), Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), and diffuse reflectance UV-visible spectroscopy (DRS). Arrangement of nanoribbons of graphitic carbon with respect to the nanomaterials was observed in TEM images, revealing the occurrence of catalytic graphitization. Variations in the intensity ratio (ID/IG), Laand LD, calculated from data obtained from Raman spectroscopy suggested that the level of graphitization increased with an increased loading of the catalysts. SEM images show the immobilization of nanoplate microballs and nanoparticles on the graphitic carbon matrix. The catalyst surface consists of Fe3+and Ti4+as the metal species, with V, Mn, and Zr being the main impurities. According to DRS spectra, the synthesized composites absorb light in the visible region efficiently. Fabricated composites effectively adsorb methylene blue via π-πinteractions, with the absorption capacities ranging from 21.18 to 45.87 mg/g. They were effective in photodegrading methylene blue under sunlight, where the rate constants varied in the 0.003-0.007 min-1range. Photogenerated electrons produced by photocatalysts captured by graphitic carbon produce O2•-radicals, while holes generate OH•radicals, which effectively degrade methylene blue molecules. TiO2-Fe3C-Fe-Fe3O4/graphitic carbon composites inhibited the growth of Escherichia coli (69%) and Staphylococcus aureus (92%) under visible light. Synthesized novel composites using natural materials comprise an ecofriendly, cost-effective solution to remove dyes, and they were effective in inhibiting the growth of Gram-negative and Gram-positive bacteria.
Open Access
Antibacterial Activity of Cu Decorated TiO2 Nanorods
(Faculty of Humanities and Sciences, SLIIT, 2023-11-01) Nilaweera, G; Thambiliyagodage, C; Jayanetti, M; Liyanaarachchi, H
Global public health is seriously threatened by the spread of infectious illnesses in general, particularly by the appearance of bacterial strains that are resistant to antibiotics. New antibacterial drugs are likely a result of recent developments in the field of nanobiotechnologies, particularly the ability to make metal oxide nanomaterials with specific morphologies. Using antibiotics for a long time period will show antibiotic resistance in host cells, which means the drug does not kill the pathogen anymore. As a solution to this problem, nanoparticles can be used. Researchers may find nanoparticles with high antibacterial activity which can kill the pathogen. This research shows the antibacterial activity of Cu decorated TiO2 nanoparticles against Klebsiella pneumoniae. In here the nanoparticles were synthesized in three weight ratios with TiO2 and CuO using hydrothermal method. Pure CuO and TiO2 were synthesized as controls. Then antibacterial activity was checked by the well diffusion method. After incubation the inhibition zones were measured, and the results were recorded. The antibacterial effect can be determined with the size of the inhibition zone. The synthesized nanoparticles were characterized using XRD to analyze physical properties such as phase composition, crystal structure. The value for inhibition zone of the best performing sample which the sample concentration is 40mg/ml is 13.17±1.53 mm which contains TiO2 : CuO (1:2) weight ratio. Therefore it can be determined that the best performing sample which has the highest antibacterial activity against Klebsiella pneumoniae is G3 which contains TiO2 : CuO (1:2) weight ratio.
Embargo
Assessing the Efficacy of Machine Learning Algorithms in Predicting Critical Properties of Gold Nanoparticles for Pharmaceutical Applications
(Springer Nature Link, 2025-07-08) Fernando, H; Mohottala, S; Jayanetti, M; Thambiliyagodage, C
Au nanoparticles are increasingly used in pharmaceuticals, but their synthesis is costly and time-intensive. Machine Learning can help optimize this process. In this research, eight distinct Machine Learning models were implemented and optimized on a dataset comprising 3000 records of gold nanoparticles. The performance of these models was assessed using four accuracy metrics and the time required for training and inference. The results are promising, with all seven models demonstrating high accuracy and low time requirements. Notably, the XGBoost and Artificial Neural Network models exhibited exceptional performance, with Mean Squared Error values of 0.0235 and 0.0098, Mean Absolute Error values of 0.1021 and 0.0674, Mean Absolute Percentage Deviation values of 0.4945 and 0.3590, R2 scores of 0.9995 and 0.9998, and inference times of 0.0029 and 0.4299 s, respectively. The Explainable Artificial Intelligence analysis of the resulting models revealed some interesting insights into how the models make the predictions and what factors heavily contribute to the nanoparticle AVG_R, allowing chemists to optimize the synthesis for gold nanoparticles better. The key contributions of the research include the design and development of eight Machine Learning models using industry-standard frameworks, the training, tuning, and evaluation of these eight models using five different metrics, and further assessment of these trained models using Explainable Artificial Intelligence. The findings indicate a substantial potential for applying neural networks in the design phase of nanoparticle synthesis, which could lead to significant reductions in both the time and cost required for synthesizing Au nanoparticles for pharmaceutical applications.
Open Access
Fabrication of Naturally Derived Chitosan and Ilmenite Sand-Based TiO2/Fe2O3/Fe-N-Doped Graphitic Carbon Composite for Photocatalytic Degradation of Methylene Blue under Sunlight
(MDPI, 2023-04-01) Mendis, A; Thambiliyagodage, C; Ekanayake, G; Liyanaarachchi, H; Jayanetti, M; Vigneswaran, S
first_pagesettingsOrder Article Reprints Open AccessArticle Fabrication of Naturally Derived Chitosan and Ilmenite Sand-Based TiO2/Fe2O3/Fe-N-Doped Graphitic Carbon Composite for Photocatalytic Degradation of Methylene Blue under Sunlight by Amavin Mendis 1,Charitha Thambiliyagodage 1,*ORCID,Geethma Ekanayake 1,Heshan Liyanaarachchi 1ORCID,Madara Jayanetti 1 andSaravanamuthu Vigneswaran 2,3,* 1 Faculty of Humanities and Sciences, Sri Lanka Institute of Information Technology, Malabe 10115, Sri Lanka 2 Faculty of Engineering and Information Technology, University of Technology Sydney, P.O. Box 123, Sydney, NSW 2007, Australia 3 Faculty of Sciences & Technology (RealTek), Norwegian University of Life Sciences, P.O. Box N-1432 Ås, Norway * Authors to whom correspondence should be addressed. Molecules 2023, 28(7), 3154; https://doi.org/10.3390/molecules28073154 Received: 15 March 2023 / Revised: 29 March 2023 / Accepted: 30 March 2023 / Published: 1 April 2023 (This article belongs to the Section Materials Chemistry) Download Browse Figures Versions Notes Abstract Fabrication of chitosan and ilmenite sand-based novel photocatalysts through the catalytic graphitization of chitosan is reported. Nanocomposites consisted of TiO2, Fe2O3 and Fe nanoparticles dispersed on a nitrogen-doped graphitic carbon framework. The surface area, pore volume and macropore structure of the carbon matrix is disturbed by the heterogeneously distributed nanoparticles. The extent of graphitization expanded with increasing metal loading as indicated by variation in the ID/IG ratio. The nanomaterial’s surface consists of Fe3+ and Ti4+, and graphitic, pyridinic and pyrrolic nitrogen were found in the carbon matrix. The band gap values of the composites varied in the 2.06–2.26 eV range. The photocatalytic activity of the synthesized nanomaterials was determined, and the highest rate constant for the photodegradation of methylene blue under sunlight was 4.4 × 10−3 min−1, which resulted with 10 mg/L MB and 25 mg of the best-performing catalyst. The rate constant rose with increasing concentrations of persulfate added to the medium. The rate constant greatly diminished with the addition of isopropyl alcohol as it scavenged hydroxyl radicals. The presence of co-pollutants including Pb2+, rhodamine B, PO43− and Cl− curtailed the rate of reaction. The activity reduced with an increasing number of uses of the catalyst.
Open Access
A Study on Conscinium fenestratum and Chitosan Biopolymer Composite for Ayurvedic Drug Delivery
(Faculty of Humanities and Sciences, SLIIT, 2024-12-04) Alwis, M; Jayanetti, M; Thambiliyagodage, C
This study delves into the synergisti c amalgamati on of Coscinium fenestratum, an Ayurvedic medicinal plant, and chitosan biopolymer. This results in the innovati ve Venivel Chitosan Composite, which has established a pioneering drug delivery system. Subsequently, the composite material, Venivel Chitosan Composite, was formulated by integrati ng Coscinium fenestratum extract and chitosan biopolymer. Structural characteristi cs of Chitosan biopolymer and Venivel Chitosan Composite were determined via scanning electron microscopy (SEM), off ering valuable insights into their morphological features. Furthermore, a comprehensive characterizati on of the composite was achieved through the analysis of X-ray diff racti on (XRD) patt erns, elucidati ng its crystalline structure. A meti culous examinati on of the in vitro drug release profi le revealed a predominant diff usion mechanism, indicati ng the potenti al suitability of this system for applicati ons in wound healing treatments. In conclusion, integrati ng Coscinium fenestratum with chitosan biopolymer presents a versati le composite with promising anti bacterial, anti oxidant, and anti - infl ammatory properti es, elevati ng its potenti al for targeted and controlled ayurvedic drug delivery applicati ons.
Open Access
Persulfate assisted photocatalytic and antibacterial activity of TiO2–CuO coupled with graphene oxide and reduced graphene oxide
(https://www.nature.com, 2024-05-31) Thambiliyagodage, C; Liyanaarachchi, H; Jayanetti, M; Ekanayake, G; Mendis, A; Samarakoon, U; Vigneswaran, S
Photocatalysts of TiO2–CuO coupled with 30% graphene oxide (GO) were hydrothermally fabricated, which varied the TiO2 to CuO weight ratios to 1:4, 1:2, 1:1, 2:1 and 4:1 and reduced to form TiO2–CuO/reduced graphene oxide (rGO) photocatalysts. They were characterized using XRD, TEM, SEM, XPS, Raman, and DRS technologies. TiO2–CuO composites and TiO2–CuO/GO degrade methylene blue when persulfate ions are present. Persulfate concentration ranged from 1, 2, 4 to 8 mmol/dm−3 in which the highest activity of 4.4 × 10–2 and 7.35 × 10–2 min−1 was obtained with 4 mmol/dm−3 for TiO2–CuO (1:4) and TiO2–CuO/GO (1:1), respectively. The presence of EDTA and isopropyl alcohol reduced the photodegradation. TiO2–CuO coupled with rGO coagulates methylene blue in the presence of persulfate ions and such coagulation is independent of light. The catalyst dosage and the concentration of the dye were varied for the best-performing samples. The antibacterial activity of the synthesized samples was evaluated against the growth of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumonia. Ti:Cu (1:2)-GO and Ti:Cu (1:4)-GO had the highest antibacterial activity against K. pneumoniae (16.08 ± 0.14 mm), P. aeruginosa (22.33 ± 0.58 mm), E. coli (16.17 ± 0.29 mm) and S. aureus (16.08 ± 0.88).
Open Access
In vitro influence of PEG functionalized ZnO–CuO nanocomposites on bacterial growth
(PubMed ID, 2024-01-14) Thambiliyagodage, C; Jayanetti, M; Liyanaarachchi, H; Ekanayake, G; Mendis, M; Usgodaarachchi, L
Polyethyleneglycol-coated biocompatible CuO–ZnO nanocomposites were fabricated hydrothermally varying Zn:Cu ratios as 1:1, 2:1, and 1:2, and their antibacterial activity was determined through the well diffusion method against the Gram-negative Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and the Gram-positive Staphylococcus aureus. The minimum inhibitory concentration and the minimum bactericidal concentration values of the synthesized samples were determined. Subsequently, the time synergy kill assay was performed to elucidate the nature of the overall inhibitory effect against the aforementioned bacterial species. The mean zone of inhibition values for all four samples are presented. The inhibitory effect increased with increasing concentration of the nanocomposite (20, 40 and 60 mg/ml) on all the bacterial species except for S. aureus. According to the MBC/MIC ratio, ZnO was found to be bacteriostatic for E. coli and P. aeruginosa, and bactericidal for S. aureus and K. pneumoniae. Zn:Cu 2:1 was bactericidal on all bacterial species. A bacteriostatic effect was observed on E. coli and P. aeruginosa in the presence of Zn:Cu 1:1 whereas, it showed a bactericidal effect on S. aureus and K. pneumoniae. Zn:Cu 1:2 exhibited a bacteriostatic effect on E. coli while a bactericidal effect was observed for E. coli, P. aeruginosa, and K. pneumoniae. The metal oxide nanocomposites were found to be more sensitive towards the Gram-positive strain than the Gram-negative strains. Further, all the nanocomposites possess anti-oxidant activity as shown by the DPPH assay.