{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:53:04Z","timestamp":1785433984733,"version":"3.56.0"},"reference-count":114,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T00:00:00Z","timestamp":1777507200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Foundation Competitive Support for Unrated Researchers grant","award":["SRUG2203291031"],"award-info":[{"award-number":["SRUG2203291031"]}]},{"name":"5th BRICS STI Framework Programme","award":["BRICS JAF # 2021\/305"],"award-info":[{"award-number":["BRICS JAF # 2021\/305"]}]},{"DOI":"10.13039\/501100001322","name":"South African Medical Research Council","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001322","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/05q60vz69","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This paper presents work on the green synthesis of the graphene quantum dots (GQDs) and carbon dots (CDs) from leaves of Erythrina caffra (E. caffra) using a simple technique to facilitate the carbonization process, from methanol and water extracts of E. caffra leaf, and their evaluation as potential antiviral agents against SARS-CoV-2. Phytochemical profiling of E. caffra leaf extracts exhibited the presence of phenols, alkaloids, steroids\/terpenoids, tannins, and flavonoids. FTIR analysis confirmed the incorporation of oxygenated functional groups inherited from the phytochemicals. UV-Vis indicated the presence of secondary metabolites in both extracts and CDs. X-ray diffraction spectra confirmed the amorphous and crystalline nature of synthesized CDs (2.51 nm) from water extracts and GQDs (0.08 nm) from methanol extracts. The CDs and GQDs exhibited respective sizes of 5.5 and 4.0 nm, with a dot-like morphology, and respective zeta potential of +200.0 and \u221212.6 mV. The results revealed that all extracts and carbon dot formulations exhibited high cell viability (&gt;90%), indicating excellent biocompatibility and minimal cytotoxicity at the tested concentration of 100 mg\/mL per sample. The SARS-CoV-2 experiments demonstrated that extracts (MeOH, H2O) and nanomaterials (CDs-H2O, GQDs-MeOH) exhibited a virus suppression efficacy of 87.86 \u00b1 4.75%, 87.95 \u00b1 0.77%, 87.95 \u00b1 3.08%, and 94.84 \u00b1 0.94%, respectively. All examined samples demonstrated viral inhibition over 88%. Both extracts and their respective nanomaterials showed that a minimum of 5 \u03bcg was required to achieve 50% antioxidant species per sample. The study highlights E. caffra as a sustainable precursor for eco-friendly carbon dot synthesis as potential antiviral and antioxidant candidates.<\/jats:p>","DOI":"10.3390\/ma19091841","type":"journal-article","created":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T08:03:47Z","timestamp":1777536227000},"page":"1841","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Green Synthesis of Graphene Quantum Dots (GQDs) and Carbon Dots (CDs) Mediated with Erythrina caffra for Potential Antiviral Properties Against SARS-CoV-2"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8571-9337","authenticated-orcid":false,"given":"Refilwe","family":"Matshitse","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Boetie M.","family":"Buta","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nothando S.","family":"Mabasa","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bongeka S.","family":"Nkosi","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lebogang A.","family":"Ramarope","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nhluvuko","family":"Vuma","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2884-6924","authenticated-orcid":false,"given":"Nomusa","family":"Sikhakhane","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2227-382X","authenticated-orcid":false,"given":"Tebogo","family":"Matlala","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2376-739X","authenticated-orcid":false,"given":"Charity E.","family":"Maepa","sequence":"additional","affiliation":[{"name":"Laboratory for Microscopy and Microanalysis, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sifiso A.","family":"Nsibande","sequence":"additional","affiliation":[{"name":"Chemistry Department, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0028, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7533-7597","authenticated-orcid":false,"given":"Daniel","family":"Makanyane","sequence":"additional","affiliation":[{"name":"Applied Radiation Department, South African Nuclear Energy Corporation Ltd., Brits 0240, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8667-8351","authenticated-orcid":false,"given":"Xavier Siwe","family":"Noundou","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, School of Pharmacy, Sefako Makgatho Health Sciences University, Ga-Rankuwa, Pretoria 0204, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"912","DOI":"10.1002\/cbf.3843","article-title":"An in vitro investigation of L-kynurenine, quinolinic acid, and kynurenic acid on B16 F10 melanoma cell cytotoxicity and morphology","volume":"41","author":"Basson","year":"2023","journal-title":"Cell Biochem. Funct."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e966","DOI":"10.1016\/S2468-2667(22)00223-7","article-title":"COVID-19 mortality and deprivation: Pandemic, syndemic, and endemic health inequalities","volume":"7","author":"McGowan","year":"2022","journal-title":"Lancet Public Health"},{"key":"ref_3","first-page":"10215","article-title":"Molecular structure, pathophysiology, and diagnosis of COVID-19","volume":"11","author":"Belmehdi","year":"2021","journal-title":"Biointerface Res. Appl. Chem."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Sharma, S., and Maheshwari, S. (2021). Protein structure and function prediction of SARS-CoV 2: Prospective antivirus active drug binding sites. IOP Conference Series: Materials Science and Engineering, IOP Publishing.","DOI":"10.1088\/1757-899X\/1170\/1\/012003"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Zhu, C., Sun, B., Zhang, X., and Zhang, B. (2020). Research progress of genetic structure, pathogenic mechanism, clinical characteristics, and potential treatments of coronavirus disease 2019. Front. Pharmacol., 11.","DOI":"10.3389\/fphar.2020.01327"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"117","DOI":"10.30574\/gscbps.2020.12.3.0275","article-title":"Role of structural and functional proteins of SARS-CoV-2","volume":"12","author":"Wabalo","year":"2020","journal-title":"GSC Biol. Pharm. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4399","DOI":"10.1038\/s41467-022-32019-3","article-title":"Structure of SARS-CoV-2 membrane protein essential for virus assembly","volume":"13","author":"Zhang","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Subramanian, G., Hage, A., Feldmann, F., Chiramel, A.I., McNally, K.L., Sturdevant, G.L., Beare, P.A., and Best, S.M. (2024). AP3B1 has type I interferon-independent antiviral function against SARS-CoV-2. Viruses, 16.","DOI":"10.3390\/v16091377"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1007\/s13204-021-01900-w","article-title":"SARS-CoV-2 and its new variants: A comprehensive review on nanotechnological application insights into potential approaches","volume":"13","author":"Raja","year":"2023","journal-title":"Appl. Nanosci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"948","DOI":"10.2174\/1381612827666210701150315","article-title":"Nanotechnology-based approaches and investigational therapeutics against COVID-19","volume":"28","author":"Rahman","year":"2022","journal-title":"Curr. Pharm. Des."},{"key":"ref_11","unstructured":"(2009). Biological Evaluation of Medical Devices\u2014Part 5: Tests for In Vitro Cytotoxicity (Standard No. ISO 10993-5:2009)."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.carbon.2018.08.016","article-title":"Biomass-waste derived graphene quantum dots and their applications","volume":"140","author":"Abbas","year":"2018","journal-title":"Carbon"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"20220285","DOI":"10.1515\/chem-2022-0285","article-title":"Graphene quantum dots: A comprehensive overview","volume":"21","author":"Fatimah","year":"2023","journal-title":"Open Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1732","DOI":"10.1021\/acssensors.9b00514","article-title":"Review of carbon and graphene quantum dots for sensing","volume":"4","author":"Li","year":"2019","journal-title":"ACS Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6371","DOI":"10.1038\/s41598-023-33652-8","article-title":"Green synthesis of multi-functional carbon dots from medicinal plant leaves for antimicrobial, antioxidant, and bioimaging applications","volume":"13","author":"Gedda","year":"2023","journal-title":"Sci. Rep."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1186\/s12951-023-01795-5","article-title":"Ultrasmall and highly biocompatible carbon dots derived from natural plant with amelioration against acute kidney injury","volume":"21","author":"Wang","year":"2023","journal-title":"J. Nanobiotechnol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"102091","DOI":"10.1016\/j.mtbio.2025.102091","article-title":"Carbon dots: A promising tool for viral infection treatment","volume":"33","author":"Gedda","year":"2025","journal-title":"Mater. Today Bio"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1596","DOI":"10.1007\/s10854-023-10907-8","article-title":"Effect of carbon quantum dots and Zn2+ ion on perovskite solar cells","volume":"34","author":"Hussien","year":"2023","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"472","DOI":"10.1039\/C9QM00592G","article-title":"Spectroscopic studies of the optical properties of carbon dots: Recent advances and future prospects","volume":"4","author":"Zhao","year":"2020","journal-title":"Mater. Chem. Front."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Lagonegro, P., Giovanella, U., and Pasini, M. (2020). Carbon dots as a sustainable new platform for organic light emitting diode. Coatings, 11.","DOI":"10.20944\/preprints202011.0547.v1"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Osorio, H.M., Castillo-Sol\u00eds, F., Barrag\u00e1n, S.Y., Rodr\u00edguez-P\u00f3lit, C., and Gonzalez-Pastor, R. (2024). Graphene quantum dots from natural carbon sources for drug and gene delivery in cancer treatment. Int. J. Mol. Sci., 25.","DOI":"10.3390\/ijms251910539"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e07244","DOI":"10.1016\/j.heliyon.2021.e07244","article-title":"Chemical composition, antioxidant activities and antibacterial activities of essential oil from Erythrina caffra Thunb. growing in South Africa","volume":"70","author":"Wintola","year":"2021","journal-title":"Heliyon"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"825","DOI":"10.3390\/futurepharmacol4040044","article-title":"Mechanistic Insights into the Mutational Landscape of the Main Protease\/3CLPro and Its Impact on Long-Term COVID-19\/SARS-CoV-2 Management","volume":"4","author":"Mushebenge","year":"2024","journal-title":"Future Pharmacol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"100087","DOI":"10.1016\/j.fufo.2021.100087","article-title":"Extraction and characterization of polyphenolic compounds and potassium hydroxycitrate from Hibiscus sabdariffa","volume":"4","author":"Singh","year":"2021","journal-title":"Future Foods"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1","DOI":"10.22271\/flora.2023.v11.i2a.855","article-title":"Plant secondary metabolites: Extraction, screening, analysis and their bioactivity","volume":"11","author":"Khade","year":"2023","journal-title":"Int. J. Herb. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3508","DOI":"10.1080\/14786419.2023.2252976","article-title":"Preparation of medicinally active extracts and phytochemical characterisation of phytoconstituents from medicinal plants","volume":"38","author":"Shafodino","year":"2024","journal-title":"Nat. Prod. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"154","DOI":"10.46542\/pe.2025.252.154167","article-title":"Icopmap Special Edition Isolation, characterisation, and determination of capsaicin compound levels in red chili fruit (Capsicum annum fructus) in IPB CH3 and carvi agrihorti varieties","volume":"25","author":"Pradana","year":"2025","journal-title":"Pharm. Educ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"121","DOI":"10.4236\/abc.2024.144011","article-title":"Ethnobotanical and Phytochemical Study of Medicinal Plants Sold in the Markets of the City of N\u2019Djamena","volume":"14","author":"Oumar","year":"2024","journal-title":"Adv. Biol. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1007\/s00436-015-4747-x","article-title":"Phytochemical screening and in vivo antimalarial activity of extracts from three medicinal plants used in malaria treatment in Nigeria","volume":"115","author":"Bankole","year":"2016","journal-title":"Parasitol. Res."},{"key":"ref_30","first-page":"126","article-title":"Phytochemical screening and Larvicidal evaluation of phyto-synthesized silver nanoparticles using Palmyra palm sprout extract","volume":"8","author":"Danbature","year":"2020","journal-title":"Biog. J. Ilm. Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"197","DOI":"10.30574\/gscbps.2020.11.3.0166","article-title":"Phytochemical composition of desert date kernel (Balanites aegyptiaca) and the physical and chemical characteristics of its oil","volume":"11","author":"Yau","year":"2020","journal-title":"GSC Biol. Pharm. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Kudamba, A., Kasolo, J.N., Bbosa, G.S., Lugaajju, A., Wabinga, H., Niyonzima, N., Ocan, M., Damani, A.M., Kafeero, H.M., and Ssenku, J.E. (2023). Phytocphytochemical Profiles of Rhoicissus Tridentata Harvested from the Slopes of Mountain Elgon, Uganda, Research Square.","DOI":"10.21203\/rs.3.rs-3654373\/v1"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Jing, H.H., Kasolo, J.N., Bbosa, G.S., Lugaajju, A., Wabinga, H., Niyonzima, N., Ocan, M., Damani, A.M., Kafeero, H.M., and Ssenku, J.E. (2023). Green Carbon Dots: Synthesis, Characterization, Properties and Biomedical Applications. J. Funct. Biomater., 14.","DOI":"10.3390\/jfb14010027"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2626006","DOI":"10.1155\/2024\/2626006","article-title":"Graphene quantum dots: Green synthesis, characterization, and antioxidant and antimicrobial potential","volume":"2024","author":"Kadyan","year":"2024","journal-title":"Int. J. Biomater."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"25354","DOI":"10.1039\/D1RA04718C","article-title":"Green synthesis of carbon dots and their applications","volume":"11","author":"Chahal","year":"2021","journal-title":"RSC Adv."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1260","DOI":"10.1021\/ed076p1260","article-title":"Are fluorescence quantum yields so tricky to measure? A demonstration using familiar stationery products","volume":"76","author":"Lavabre","year":"1999","journal-title":"J. Chem. Educ."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1039\/B315319C","article-title":"Photophysical and photochemical studies of zinc (II) phthalocyanine derivatives\u2014Effects of substituents and solvents","volume":"28","author":"Ogunsipe","year":"2004","journal-title":"New J. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"095710","DOI":"10.1088\/1361-6528\/ab589c","article-title":"S, N co-doped graphene quantum dots decorated CdSe for enhanced photoelectric properties","volume":"31","author":"Ouyang","year":"2020","journal-title":"Nanotechnology"},{"key":"ref_39","first-page":"428","article-title":"The reflection of X-rays by crystals","volume":"88","author":"Bragg","year":"1913","journal-title":"Proc. R. Soc. Lond. Ser. A Contain. Pap. Math. Phys. Character"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"4288","DOI":"10.1039\/c3ay40367j","article-title":"Application of free radical diphenylpicrylhydrazyl (DPPH) to estimate the antioxidant capacity of food samples","volume":"5","author":"Pyrzynska","year":"2013","journal-title":"Anal. Methods"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Rubab, M., Chelliah, R., and Oh, D.-H. (2022). Screening for antioxidant activity: Diphenylpicrylhydrazine (DPPH) assay. Methods in Actinobacteriology, Springer.","DOI":"10.1007\/978-1-0716-1728-1_61"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"147","DOI":"10.31024\/ajpp.2018.4.2.8","article-title":"Review on antioxidant evaluation methods: And models In-vitro in-vivo","volume":"4","author":"Garg","year":"2018","journal-title":"Asian J. Pharm. Pharmacol."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Salhi, A., Zannagui, C., Elyoussfi, A., Ahari, M., Mourabit, F., Amhamdi, H., Akichouh, E.H., and Barkany, S.E. (2024). Exploring the Antioxidant Activity of Selected Aromatic and Medicinal Plants. Medicinal Plants-Harnessing the Healing Power of Plants, IntechOpen.","DOI":"10.5772\/intechopen.1005878"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"18028","DOI":"10.1038\/s41598-023-45030-5","article-title":"Efficacy of Various Extracting Solvents on Phytochemical Composition, Antioxidant Potential, Total Phenolic Content, and Antibacterial Properties, of Moroccan Mentha longifolia L. Leaf Extracts against Multidrug-Resistant Pathogenic Bacteria","volume":"13","author":"Tourabi","year":"2023","journal-title":"Sci. Rep."},{"key":"ref_45","first-page":"18574","article-title":"The influence of cooking methods on the antioxidant status of Tetrapleura tetrapetra","volume":"22","author":"Asogwa","year":"2022","journal-title":"Afr. J. Food Agric. Nutr. Dev."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"722","DOI":"10.22207\/JPAM.18.1.62","article-title":"Antimicrobial Activity against Antibiotic-resistant Pathogens and Antioxidant Activity and LCMS\/MS Phytochemical Content Analysis of Selected Medicinal Plants","volume":"18","author":"Thakur","year":"2024","journal-title":"J. Pure Appl. Microbiol."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"71","DOI":"10.2306\/scienceasia1513-1874.2006.32(s1).071","article-title":"Two endemic species of macroalgae in Nan River, northern Thailand, as therapeutic agents","volume":"32","author":"Peerapornpisal","year":"2006","journal-title":"Sci. Asia"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Tajuddeen, N., Swart, T., Hoppe, H.C., and van Heerden, F.R. (2021). Antiplasmodial and cytotoxic flavonoids from Pappea capensis (Eckl. & Zeyh.) leaves. Molecules, 26.","DOI":"10.3390\/molecules26133875"},{"key":"ref_49","unstructured":"W\u0119glarz-Tomczak, E., Tomczak, J.M., Talma, M., and Brul, S. (2020). Ebselen as a highly active inhibitor of PLProCoV2. BioRxiv."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"3625","DOI":"10.1007\/s00436-021-07250-4","article-title":"Establishment of a transient transfection system for Babesia sp. Xinjiang using homologous promoters","volume":"120","author":"Wang","year":"2021","journal-title":"Parasitol. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"15036","DOI":"10.1038\/s41598-018-33042-5","article-title":"Robust enhancement of lentivirus production by promoter activation","volume":"8","author":"Suzuki","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1186\/s13578-021-00560-1","article-title":"The YAP\/HIF-1\u03b1\/miR-182\/EGR2 axis is implicated in asthma severity through the control of Th17 cell differentiation","volume":"11","author":"Zhou","year":"2021","journal-title":"Cell Biosci."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"e9114949574","DOI":"10.33448\/rsd-v14i9.49574","article-title":"Optimizing the solvent mixture for extracting phenolic compounds with antioxidant and phytotoxicity activity from Myrcia fallax leaves using the I-optimal design","volume":"14","author":"Santos","year":"2025","journal-title":"Res. Soc. Dev."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"449","DOI":"10.3746\/pnf.2020.25.4.449","article-title":"Study of flavonoid\/hydroxypropyl-\u03b2-cyclodextrin inclusion complexes by UV-Vis, FT-IR, DSC, and X-Ray diffraction analysis","volume":"25","author":"Kim","year":"2020","journal-title":"Prev. Nutr. Food Sci."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"222","DOI":"10.22271\/phyto.2025.v14.i3c.15371","article-title":"Phytochemical characterization, antioxidant potential, and cytotoxic activity of Erythrina variegata leaf extract an integrated spectroscopic and bioassay approach","volume":"14","author":"Santhosh","year":"2025","journal-title":"J. Pharmacogn. Phytochem."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"4019","DOI":"10.1016\/j.arabjc.2019.05.007","article-title":"Erysacleuxins C and D, new isoflavones from the twigs of Erythrina sacleuxii Hua and their cytotoxic activity","volume":"13","author":"Ombito","year":"2020","journal-title":"Arab. J. Chem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.saa.2017.01.002","article-title":"A cockspur for the DSS cells: Erythrina crista-galli sensitizers","volume":"176","author":"Enciso","year":"2017","journal-title":"Spectrochim. Acta Part A Mol. Biomol. Spectrosc."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"427","DOI":"10.4314\/bcse.v30i3.11","article-title":"Cytotoxic flavonoids from Erythrina caffra Thunb","volume":"30","author":"Desta","year":"2016","journal-title":"Bull. Chem. Soc. Ethiop."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1387","DOI":"10.21931\/RB\/2020.05.04.18","article-title":"Phytochemical screening and in vitro anti-inflammatory activity of ethanolic extract of Epidendrum coryophorum leaves","volume":"5","author":"Mera","year":"2020","journal-title":"Bionatura"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"30869","DOI":"10.1039\/D3RA06300C","article-title":"Green one-step synthesis of mushroom-derived carbon dots as fluorescent sensors for Fe 3+ detection","volume":"13","author":"Klongklaw","year":"2023","journal-title":"RSC Adv."},{"key":"ref_61","first-page":"68","article-title":"The roles of intermediate fluorophores on the optical properties of bottom-up synthesized carbon nanodots","volume":"2","author":"Nguyen","year":"2023","journal-title":"HPU2 J. Sci. Nat. Sci. Technol."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"111578","DOI":"10.1016\/j.colsurfb.2021.111578","article-title":"One-pot bioinspired synthesis of fluorescent metal chalcogenide and carbon quantum dots: Applications and potential biotoxicity","volume":"200","author":"Omran","year":"2021","journal-title":"Colloids Surf. B Biointerfaces"},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"9915","DOI":"10.1038\/s41598-024-60726-y","article-title":"Microwave-assisted synthesis, characterization and in vitro biomedical applications of Hibiscus rosa-sinensis Linn.-mediated carbon quantum dots","volume":"14","author":"Yalshetti","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_64","first-page":"1","article-title":"Nanofabrication and characterization of green-emitting N-doped carbon dots derived from pulp-free lemon juice extract","volume":"8","author":"Iqba","year":"2023","journal-title":"Nanofabrication"},{"key":"ref_65","unstructured":"Ts\u2019itso, S. (2023). Evaluation of Silver Nanoparticles Synthesised from Gnidia Burchellii Leaf and Flower Extracts for Cytotoxicity, Antimicrobial and Antioxidant Activities, in Department of Biology. [Master\u2019s Thesis, National University of Lesotho]."},{"key":"ref_66","doi-asserted-by":"crossref","unstructured":"Olawale, F., Bodede, O., Ariatti, M., and Singh, M. (2025). Isolation, Characterization, Antioxidant and Anticancer Activities of Compounds from Erythrina caffra Stem Bark Extract. Antioxidants, 14.","DOI":"10.3390\/antiox14091035"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"163","DOI":"10.5530\/097484900288","article-title":"FTIR based metabolomics profiling and fingerprinting of some medicinal plants: An attempt to develop an approach for quality control and standardization of herbal materials","volume":"15","author":"Sahoo","year":"2022","journal-title":"Pharmacogn. Res."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"38","DOI":"10.4236\/jtst.2019.52004","article-title":"Authentication of Rothmannia whitfieldii Dye Extract with FTIR Spectroscopy","volume":"5","author":"Nnorom","year":"2019","journal-title":"J. Text. Sci. Technol."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"1568","DOI":"10.22146\/ijc.64360","article-title":"The use of chemometrics for classification of Sidaguri (Sida rhombifolia) based on FTIR spectra and antiradical activities","volume":"21","author":"Rohman","year":"2021","journal-title":"Indones. J. Chem."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"315","DOI":"10.22159\/ijpps.2017v9i1.11053","article-title":"Screening for phytochemicals and FTIR analysis of Myristica dactyloids fruit extracts","volume":"9","author":"Rajiv","year":"2017","journal-title":"Int. J. Pharm. Pharm. Sci."},{"key":"ref_71","first-page":"279","article-title":"In vitro antimalarial susceptibility of Plasmodium Falciparum and Plasmodium Berghei isolates to selected antimalarial agents, column chromatographic subfractions of Glyphaea Brevis leaves extract and FTIR and GCMS of SF8","volume":"34","author":"Anjuwon","year":"2023","journal-title":"Trop. Life Sci. Res."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"12333","DOI":"10.1038\/s41598-020-69264-9","article-title":"Ultrafast synthesis of carbon quantum dots from fenugreek seeds using microwave plasma enhanced decomposition: Application of C-QDs to grow fluorescent protein crystals","volume":"10","author":"Dager","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_73","doi-asserted-by":"crossref","unstructured":"Mohanta, Y.K., Panda, S.K., Jayabalan, R., Sharma, N., Bastia, A., and Mohanta, T.K. (2017). Antimicrobial, Antioxidant and Cytotoxic Activity of Silver Nanoparticles Synthesized by Leaf Extract of Erythrina suberosa (Roxb.). Front. Mol. Biosci., 4.","DOI":"10.3389\/fmolb.2017.00014"},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1016\/j.cherd.2015.10.009","article-title":"A comparative study of spray-dried medicinal plant aqueous extracts. Drying performance and product quality","volume":"104","author":"Gallo","year":"2015","journal-title":"Chem. Eng. Res. Des."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"2227","DOI":"10.17576\/jsm-2025-5409-10","article-title":"Anticancer Efficacy of Silver Nanoparticles Synthesized from Erythrina variegata L. Leaves Extract against A549 Lung Cancer Cell Line","volume":"54","author":"Tan","year":"2025","journal-title":"Sains Malays."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"17704","DOI":"10.1039\/C7RA01029J","article-title":"Graphene quantum dots: Effect of size, composition and curvature on their assembly","volume":"7","author":"Elvati","year":"2017","journal-title":"RSC Adv."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"2343","DOI":"10.1002\/asia.201700814","article-title":"Fluorescence and sensing applications of graphene oxide and graphene quantum dots: A review","volume":"12","author":"Zheng","year":"2017","journal-title":"Chem. Asian J."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"2924","DOI":"10.1039\/C9NA00164F","article-title":"Hydrothermal synthesis of carbon nanodots from bovine gelatin and PHM3 microalgae strain for anticancer and bioimaging applications","volume":"1","author":"Amjad","year":"2019","journal-title":"Nanoscale Adv."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"4850","DOI":"10.1039\/C7RA12522D","article-title":"N-doped carbon dots from phenol derivatives for excellent colour rendering WLEDs","volume":"8","author":"Liu","year":"2018","journal-title":"RSC Adv."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1002\/eem2.12038","article-title":"Biomass-Derived Carbon Dots and Their Applications","volume":"2","author":"Meng","year":"2019","journal-title":"Energy Environ. Mater."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"1068","DOI":"10.3762\/bjnano.13.93","article-title":"Recent advances in green carbon dots (2015\u20132022): Synthesis, metal ion sensing, and biological applications","volume":"13","author":"Kanwal","year":"2022","journal-title":"Beilstein J. Nanotechnol."},{"key":"ref_82","doi-asserted-by":"crossref","unstructured":"Omar, N.A.S., Fen, Y.P., Irmawati, R., Hashim, H.S., Ramdzan, N.S., and Fauzi, N.I.M. (2022). A Review on Carbon Dots: Synthesis, Characterization and Its Application in Optical Sensor for Environmental Monitoring. Nanomaterials, 12.","DOI":"10.3390\/nano12142365"},{"key":"ref_83","doi-asserted-by":"crossref","unstructured":"Rilievo, G., Magro, M., Tonolo, F., Cecconello, A., Rutigliano, L., Cencini, A., Molinari, S., Paolo, M.L.D., Fiorucci, C., and Rossi, M.N. (2023). Spermine Oxidase\u2013Substrate Electrostatic Interactions: The Modulation of Enzyme Function by Neighboring Colloidal \u0263-Fe2O3. Biomolecules, 13.","DOI":"10.20944\/preprints202311.0583.v1"},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"6471","DOI":"10.1039\/C7RA08716K","article-title":"Structure and characterisation of hydroxyethylcellulose\u2013silica nanoparticles","volume":"8","author":"Mansfield","year":"2018","journal-title":"RSC Adv."},{"key":"ref_85","doi-asserted-by":"crossref","first-page":"055002","DOI":"10.1088\/1681-7575\/ab3073","article-title":"Interlaboratory comparison of nanoparticle size measurements between NMIJ and NIST using two different types of dynamic light scattering instruments","volume":"56","author":"Takahashi","year":"2019","journal-title":"Metrologia"},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"9793","DOI":"10.1038\/srep09793","article-title":"Avoiding drying-artifacts in transmission electron microscopy: Characterizing the size and colloidal state of nanoparticles","volume":"5","author":"Michen","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"7267","DOI":"10.1039\/C4CS00128A","article-title":"Nanoparticle counting: Towards accurate determination of the molar concentration","volume":"43","author":"Shang","year":"2014","journal-title":"Chem. Soc. Rev."},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"84","DOI":"10.2516\/stet\/2024050","article-title":"Investigating the crystallite morphologies and aggregation in boehmite powders: A combined analysis of two-and three-dimensional electron microscopy with X-ray diffraction","volume":"79","author":"Sudheer","year":"2024","journal-title":"Sci. Technol. Energy Transit."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"13799","DOI":"10.1039\/D1RA02102H","article-title":"Anisotropic crystallite size distributions in LiFePO 4 powders","volume":"11","author":"Bobyl","year":"2021","journal-title":"RSC Adv."},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.matchar.2013.09.002","article-title":"Metrological characterization of X-ray diffraction methods at different acquisition geometries for determination of crystallite size in nano-scale materials","volume":"85","author":"Uvarov","year":"2013","journal-title":"Mater. Charact."},{"key":"ref_91","doi-asserted-by":"crossref","unstructured":"Kong, J., Wei, Y., Zhou, F., Shi, L., Zhao, S., Wan, M., and Zhang, X. (2024). Carbon Quantum Dots: Properties, Preparation, and Applications. Molecules, 29.","DOI":"10.3390\/molecules29092002"},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"262","DOI":"10.1186\/s12951-022-01477-8","article-title":"Nanoparticle classification, physicochemical properties, characterization, and applications: A comprehensive review for biologists","volume":"20","author":"Joudeh","year":"2022","journal-title":"J. Nanobiotechnol."},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1186\/1556-276X-9-108","article-title":"Cellular distribution and cytotoxicity of graphene quantum dots with different functional groups","volume":"9","author":"Yuan","year":"2014","journal-title":"Nanoscale Res. Lett."},{"key":"ref_94","doi-asserted-by":"crossref","first-page":"118293","DOI":"10.1016\/j.trac.2025.118293","article-title":"Recent advances in graphene quantum dots: Chemistry of synthesis, surface modifications, and improved properties for biomedical applications","volume":"191","author":"Panda","year":"2025","journal-title":"TrAC Trends Anal. Chem."},{"key":"ref_95","unstructured":"Fan, J. (2018). Evaluation of the Safety and Drug Delivery Efficacy of Carbon Dots in In Vitro and In Vivo Models. [Ph.D. Thesis, Universit\u00e9 de Strasbourg]."},{"key":"ref_96","doi-asserted-by":"crossref","first-page":"3513","DOI":"10.1039\/D0NA00935K","article-title":"Influence of surface charge of graphene quantum dots on their uptake and clearance in melanoma cells","volume":"3","author":"Ramana","year":"2021","journal-title":"Nanoscale Adv."},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"3183","DOI":"10.1002\/adfm.201500624","article-title":"Integrative self-assembly of graphene quantum dots and biopolymers into a versatile biosensing toolkit","volume":"25","author":"Lin","year":"2015","journal-title":"Adv. Funct. Mater."},{"key":"ref_98","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/j.foodres.2014.11.030","article-title":"An efficient methodology for quantification of synergy and antagonism in single electron transfer antioxidant assays","volume":"67","author":"Prieto","year":"2015","journal-title":"Food Res. Int."},{"key":"ref_99","doi-asserted-by":"crossref","first-page":"34456","DOI":"10.1039\/D1RA06317K","article-title":"Effect of hydroxyl on antioxidant properties of 2, 3-dihydro-3, 5-dihydroxy-6-methyl-4 H-pyran-4-one to scavenge free radicals","volume":"11","author":"Chen","year":"2021","journal-title":"RSC Adv."},{"key":"ref_100","doi-asserted-by":"crossref","unstructured":"Gulcin, \u0130., and Alwasel, S.H. (2023). DPPH radical scavenging assay. Processes, 11.","DOI":"10.3390\/pr11082248"},{"key":"ref_101","doi-asserted-by":"crossref","first-page":"20016","DOI":"10.1038\/s41598-022-24648-x","article-title":"Synthesis, characterization, and the influence of energy of irradiation on optical properties of ZnO nanostructures","volume":"12","author":"Abdelghani","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_102","first-page":"64","article-title":"In vitro cytotoxicity and cell viability assays: Principles, advantages, and disadvantages","volume":"Volume 2","year":"2018","journal-title":"Genotoxicity\u2014A Predictable Risk to Our Actual World"},{"key":"ref_103","doi-asserted-by":"crossref","first-page":"835","DOI":"10.1039\/b704513a","article-title":"Cellular impedance biosensors for drug screening and toxin detection","volume":"132","author":"Asphahani","year":"2007","journal-title":"Analyst"},{"key":"ref_104","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1039\/C9QM00658C","article-title":"Carbon dots: A booming material for biomedical applications","volume":"4","author":"Su","year":"2020","journal-title":"Mater. Chem. Front."},{"key":"ref_105","first-page":"1023","article-title":"Graphene quantum dots: An emerging material for biological applications","volume":"32","author":"Zhang","year":"2012","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_106","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1016\/j.tim.2016.03.010","article-title":"Improving viral protease inhibitors to counter drug resistance","volume":"24","author":"Yilmaz","year":"2016","journal-title":"Trends Microbiol."},{"key":"ref_107","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.ab.2017.01.020","article-title":"Acquisition of accurate data from intramolecular quenched fluorescence protease assays","volume":"522","author":"Arachea","year":"2017","journal-title":"Anal. Biochem."},{"key":"ref_108","doi-asserted-by":"crossref","unstructured":"Raekiansyah, M., Tun, M.M.N., Ang, A., Lee, A., Macalino, J.S., Billones, J., Takamatsu, Y., Urano, T., Murao, L.A.E., and Quiming, N. (2025). Antiviral Activity of Medicinal Plant Extracts Vitex negundo and Macaranga tanarius Against SARS-CoV-2. Pathogens, 14.","DOI":"10.3390\/pathogens14080820"},{"key":"ref_109","first-page":"78","article-title":"Virtual screening campaigns and ADMET evaluation to unlock the potency of flavonoids from Erythrina as 3CLpro SARS-CoV-2 inhibitors","volume":"13","author":"Nishinarizki","year":"2023","journal-title":"J. Appl. Pharm. Sci."},{"key":"ref_110","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1007\/s13205-021-02905-6","article-title":"Use of nanotechnology in combating coronavirus","volume":"11","author":"Gharpure","year":"2021","journal-title":"3 Biotech"},{"key":"ref_111","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1039\/D2MA00797E","article-title":"COVID-19 mitigation: Nanotechnological intervention, perspective, and future scope","volume":"4","author":"Adhikari","year":"2023","journal-title":"Mater. Adv."},{"key":"ref_112","doi-asserted-by":"crossref","unstructured":"Fedorov, V., Kholina, E., Khruschev, S., Kovalenko, I., Rubin, A., and Strakhovskaya, M. (2022). Electrostatic map of the SARS-CoV-2 virion specifies binding sites of the antiviral cationic photosensitizer. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23137304"},{"key":"ref_113","doi-asserted-by":"crossref","first-page":"101466","DOI":"10.1016\/j.cocis.2021.101466","article-title":"SARS-CoV-2 virion physicochemical characteristics pertinent to abiotic substrate attachment","volume":"55","author":"Adamczyk","year":"2021","journal-title":"Curr. Opin. Colloid Interface Sci."},{"key":"ref_114","first-page":"3264","article-title":"Coronavirus COVID-19 surface properties: Electrical charges status","volume":"2766","author":"Latyshev","year":"2021","journal-title":"Int. J."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/9\/1841\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T13:19:48Z","timestamp":1778505588000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/9\/1841"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,30]]},"references-count":114,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["ma19091841"],"URL":"https:\/\/doi.org\/10.3390\/ma19091841","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,30]]}}}