Author(s):
Namita Bhardwaj, Anjali Padey, Arvind Kumar Prajapati
Email(s):
anjalipadey2203@gmail.com
DOI:
10.52711/0974-360X.2025.00741 
Address:
Namita Bhardwaj1, Anjali Padey2*, Arvind Kumar Prajapati3
1Professor, Department of Chemistry, Dr. C.V. Raman University, Kota, Bilaspur, (C.G.),
2Research Scholar, Department of Chemistry, Dr. C.V. Raman University, Kota, Bilaspur, (C.G.),
3Scientist, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, (Kerala)
*Corresponding Author
Published In:
Volume - 18,
Issue - 11,
Year - 2025
ABSTRACT:
Natural product-derived carbon quantum dots (CQDs) have recently drawn much attention owing to their excellent optical and electrical properties. This study aims to develop CQDs that can be applied to fluorescent inks and detect Fe3+ metal ions in aqueous solutions. Watermelon peel waste was converted into CQDs using a one-step, straightforward, environmentally friendly, and efficient hydrothermal process. The resulting CQDs were analyzed with various techniques, including UV-Visible absorbance spectroscopy, spectrofluorometric, X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. According to the available literature, the CQDs exhibit strong blue fluorescence that is very photostable, good enough to allow their possible use in a fluorescent ink application. The CQDs were examined regarding their potential as sensors to detect metal ions by studying how much their fluorescence was quenched when mixed with several different metal ions in solution. Examination of the data indicates that the only metal ions that significantly quenched the fluorescence of the CQDs were the Fe3+ metal ions, and these caused about an 80% reduction in the amount of fluorescence that was observable from the CQDs. This study suggests that these watermelon peel-derived carbon dots are probably good candidates for both fluorescent inks and sensors for detecting metal ions.
Cite this article:
Namita Bhardwaj, Anjali Padey, Arvind Kumar Prajapati. Hydrothermally Synthesized Carbon Quantum Dots from Watermelon Peel for Fluorescent Ink and selective Sensing of Fe³⁺, Pb²⁺, and Ag⁺ Ions. Research Journal Pharmacy and Technology. 2025;18(11):5137-1. doi: 10.52711/0974-360X.2025.00741
Cite(Electronic):
Namita Bhardwaj, Anjali Padey, Arvind Kumar Prajapati. Hydrothermally Synthesized Carbon Quantum Dots from Watermelon Peel for Fluorescent Ink and selective Sensing of Fe³⁺, Pb²⁺, and Ag⁺ Ions. Research Journal Pharmacy and Technology. 2025;18(11):5137-1. doi: 10.52711/0974-360X.2025.00741 Available on: https://www.rjptonline.org/AbstractView.aspx?PID=2025-18-11-3
REFERENCES:
1. Kang S, Han H, Lee K, Kim KM. Ultrasensitive detection of ions using functionalized graphene quantum dots fabricated by a one-step pulsed laser ablation process. ACS Omega. 2022; 7: 2074–2081.
2. Atchudan R, Edison TNJI, Perumal S, Vinodh R, Lee YR. Fluorescent carbon quantum dots for food contaminants detection applications. J Environ Chem Eng. 2024; 12: 111999.
3. Wang R, Wang Y, Yang J, et al. Highly fluorescent graphene quantum dots from biorefinery waste for tri-channel sensitive detection of ions. J Hazard Mater. 2021; 412:125096.
4. Liu J, Li R, Yang B. Carbon dots: A new type of carbon-based nanomaterial with wide applications. ACS Cent Sci. 2020; 6: 2179–2195.
5. Li M, et al. Preparation of highly oriented single crystal arrays of C8-BTBT by epitaxial growth on oriented isotactic polypropylene. J Mater Chem C. 2020; 8: 2155–2159.
6. Balkanloo PG, Sharifi KM, Marjani AP. Graphene quantum dots: Synthesis, characterization, and application in wastewater treatment – a review. Mater Adv. 2023; 4: 4272–4293.
7. Nguyen VT, et al. green synthesis of carbon quantum dots through one-step hydrothermal approach by orange juice for rapid and accurate detection of dopamine. J Fluoresc. 2023; 34: 2665–2677.
8. Manivannan R, et al. Bioconversion of watermelon peels for the production of carbon quantum dots. Biomass Convers Biorefin. 2022; 14:6987–6998.
9. Ali OM, et al. green biosynthesis of titanium dioxide quantum dots using watermelon peel waste: Antimicrobial, antioxidant, and anticancer activities. Biomass Convers Biorefin. 2022; 14: 6987–6998.
10. Karthikeyan M, et al. Label-free detection of ampicillin in milk and water using fluorescence carbon dots synthesized from Citrus limetta peel. Diam Relat Mater. 2025; 152:111892.
11. Liu X, et al. B-doped graphene quantum dots array as fluorescent sensor platforms for plasticizers detection. Sens Actuators B Chem. 2023; 376:132989.
12. Singh AK, et al. Graphene quantum dot-based optical sensing platform for aflatoxin B1 detection via the resonance energy transfer phenomenon. ACS Appl Bio Mater. 2022; 5: 1179–1186.
13. Kwee HE, et al. Single-layered graphene quantum dots with self-passivated layer from xylan for visual detection of trace chromium (VI). Chem Eng J. 2022; 435:131833.
14. Liu H, et al. Graphene quantum dots as metal-free nanozymes for chemo-dynamic therapy of cancer. Matter. 2024;7:977–990.
15. Al-Qahtani A, et al. green construction of metal- and additive-free citrus peel-derived carbon dot/g-C3N4 photocatalysts. Food Chem. 2023; 425: 136470.
16. Zhu L, et al. Lignin-based fluorescence-switchable graphene quantum dots for ascorbic acid detection. Int J Biol Macromol. 2022; 194: 254–263.
17. Revesz IA, Hickey SM, Sweetman MJ. Metal ion sensing with graphene quantum dots: Detection of harmful contaminants and biorelevant species. J Mater Chem B. 2022; 10: 4346–4362.
18. He W, et al. Visual determination of copper (II) using a biomass-sourced carbon quantum dot (CQD) ratio-metric fluorescent probe. Anal Lett. 2024; 58: 228–241.
19. Surendran P, et al. Synthesis of fluorescent carbon quantum dots from Manihot esculenta waste peels for nonlinear optical and biological applications. Chem Phys Impact. 2024; 8: 100515.
20. Hu XH, Zhang R, Wu Z, Xiong S. Concentrated solar induced graphene. ACS Omega. 2022; 7: 27263–27271.
21. Huynh TV, et al. Erbium-doped graphene quantum dots with up- and down-conversion luminescence for effective detection of ferric ions in water and human serum. Sens Actuators B Chem. 2021; 328:129056.
22. Tam TV, et al. Novel paper- and fiber optic-based fluorescent sensor for glucose detection using aniline-functionalized graphene quantum dots. Sens Actuators B Chem. 2021; 329: 129250.
23. Kadyan P, et al. Comprehensive review on synthesis, applications, and challenges of graphene quantum dots (GQDs). J Nanomater. 2023; 2023: 1–26.
24. Wu J, et al. Synthesis and applications of carbon quantum dots derived from biomass waste: A review. Environ Chem Lett. 2023; 21: 3393–3424.
25. Ahmed T, Noman MT, Shahid M, Jatoi AW. Green synthesis of carbon quantum dots from Citrus limon peels and their applications. J Photochem Photobiol B Biol. 2020; 203: 111733.
26. Arsalani N, Nezhad-Mokhtari P, Jabbari E. Green synthesis of carbon dots using sweet lime peel extract for cell imaging and biosensing of tetracycline. J Photochem Photobiol B Biol. 2019; 197: 111546.
27. Banerjee A, Mitra S, Pal A. Fluorescent nitrogen-doped carbon dots synthesized from banana peel for selective detection of chlorpyrifos. Food Chem. 2020; 310: 125920.
28. Bhattacharya S, Roy S, Dutta T. Carbon quantum dots from Azadirachta indica leaves: Characterization and application as sensor for ions. Sens Actuators B Chem. 2018; 258: 525–532.
29. Chandra S, Patra P, Pathan SH. Synthesis of nitrogen-doped carbon dots for “turn-off” fluorescent detection of ions. J Nanobiotechnol. 2014; 12: 33.
30. Chen B, Li F, Li S. Microwave-assisted synthesis of carbon dots for rapid detection of pesticides. Anal Methods. 2017; 9(21): 3211–3217.
31. Das R, Bandyopadhyay R, Pramanik P. Carbon quantum dots from natural sources for bioimaging and sensing applications. Curr Opin Green Sustain Chem. 2019; 17:30–36.
32. Dong Y, Pang H, Yang HB. Carbon-based dots co-doped with nitrogen and sulfur for highly selective detection of mercury (II) ion. Anal Chem. 2013; 85(13): 6223–6230.
33. Ghosh S, Sahoo AK, Das TK. Sustainable synthesis of fluorescent carbon quantum dots from citrus peels and their use in detection of antibiotics. Environ Res. 2022; 212: 113350.
34. Rajput P, et al. Synthesis of carbon quantum dots for sensitive detection of ions in aqueous media. Res J Pharm Technol. 2020; 13(9): 4302–4306.
35. Sharma A, et al. green synthesis of CQDs from banana peels and their use in heavy metal ion detection. Res J Pharm Technol. 2021; 14(3): 1451–1457.
36. Kumar V, et al. Carbon dots from agro-waste for biosensing of antibiotics in water. Res J Pharm Technol. 2022; 15(5): 2301–2307.
37. Jha R, et al. One-pot hydrothermal synthesis of fluorescent CQDs from pomegranate peels. Res J Pharm Technol. 2021; 14(12): 6562–6568.
38. Gupta S, et al. Fluorescent nanoprobes based on carbon dots for metal ion sensing. Res J Pharm Technol. 2020; 13(6): 2761–2767.
39. Singh A, et al. Biowaste-derived CQDs for rapid detection of ions in drinking water. Res J Pharm Technol. 2023; 16(4): 1650–1656.
40. Thakur D, et al. Real sample application of carbon quantum dots for pesticide residue detection. Res J Pharm Technol. 2021; 14(8): 4031–4036.
41. Patil A, et al. Multifunctional CQDs for drug residue detection in milk and water. Res J Pharm Technol. 2022; 15(10): 4845–4851.