Red Carbon Dots as Theranostic Nanoplatforms for Cancer: Synthesis, Functionalization, Imaging, and Therapeutic Applications

The tunable optical features, high photostability, and water-dispersibility, along with the rich surface functional groups, of red carbon dots have made them promising theranostic nanoplatforms for cancer diagnosis and therapy. The red and NIR emissive carbon dots have great potential in biomedical applications, as they have several advantages over conventional blue and green emissive carbon dots, such as reduced tissue autofluorescence, enhanced in vivo imaging contrast, deeper tissue penetration, and reduced tissue photodamage. They are excellent candidates for fluorescence imaging, image-guided therapy, and light-responsive cancer therapy. In this review, recent progress in red carbon dots as nano-platforms with multifunctionality for cancer theranostics, focusing on their synthesis, functionalization, imaging performance, and therapeutic applications, is summarized. The major synthetic strategies such as hydrothermal, solvothermal, microwave-assisted, and precursor-engineered approaches are discussed with respect to their impact on particle size, surface chemistry, quantum yield, red-shifted emission, and their photothermal and/or photodynamic efficacy. Significant emphasis is on surface functionalization strategies to enhance the properties of colloidal stability, biocompatibility, tumor targeting, cellular uptake, loading, and stimuli-responsive release. The review also emphasizes the potential applications of red carbon dots in cancer imaging, targeted drug delivery, photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), and synergistic cancer therapy. Although significant advances have been made, there are several challenges to address, such as the definition of emission mechanisms, batch-to-batch variability, lack of long-term biosafety data, and difficulties in clinical translation and evaluation of pharmacokinetics. In summary, red carbon dots are an intriguing and promising family of carbon nanomaterials in precision oncology. They will need to understand these structure–property–function relationships in-depth to facilitate the design of safer, reproducible, and clinically applicable theranostic systems.

Red carbon dots; theranostic nanoplatforms; cancer imaging; photodynamic therapy

1. ANSARY A, OSMAN A, EL-KHOULY M E. Doxorubicin-loaded pH-responsive porphyrin-derived carbon dots as a promising biocompatible drug delivery system for effective chemotherapy of breast cancer [J]. RSC advances, 2025, 15(9): 6457-6473. [Google Scholar] [Crossref]

2. XU D, GUO D, ZHANG J, et al. Innovative tumor interstitial fluid-triggered carbon dot-docetaxel nanoassemblies for targeted drug delivery and imaging of HER2-positive breast cancer [J]. International Journal of Pharmaceutics, 2024, 657: 124145. [Google Scholar] [Crossref]

3. AZMI F, XU X, DUONG H, et al. Renal clearable sucrose carbon dots for doxorubicin delivery to treat renal carcinoma [J]. Nanoscale advances, 2025, 7(9): 2751-2760. [Google Scholar] [Crossref]

4. XUE B, LI Q, XING Y, et al. Nucleus delivery of doxorubicin by gadolinium-functionalized carbon dot drug delivery system for HCC imaging and therapy [J]. Microchimica Acta, 2025, 192(9): 616. [Google Scholar] [Crossref]

5. GONG W, NAN K, GAO X, et al. Red-emissive carbon dots-based composite nanoparticles for photothermal-enhanced synergistic cancer therapy [J]. Journal of Materials Science, 2026: 1-21. [Google Scholar] [Crossref]

6. KARIMINIA S, SHAMSIPUR M, BARATI A. Fluorescent folic acid-chitosan/carbon dot for pH-responsive drug delivery and bioimaging [J]. International Journal of Biological Macromolecules, 2024, 254: 127728. [Google Scholar] [Crossref]

7. JANA P, SA P, SAKAI K, et al. Enhancement of the Antitumor Efficacy of Docetaxel Using αvβ3 Integrin and CD44 Dual Receptor-Targeted Carbon Dot-Based Nanodelivery in Breast Cancer [J]. Molecular pharmaceutics, 2025, 22(10): 6120-6140. [Google Scholar] [Crossref]

8. HETTIARACHCHI S D, CILINGIR E K, MAKLOUF H, et al. pH and redox triggered doxorubicin release from covalently linked carbon dots conjugates [J]. Nanoscale, 2021, 13(10): 5507-5518. [Google Scholar] [Crossref]

9. MIAO X, QU D, YANG D, et al. Synthesis of carbon dots with multiple color emission by controlled graphitization and surface functionalization [J]. Advanced materials, 2018, 30(1): 1704740. [Google Scholar] [Crossref]

10. DING H, WEI J-S, ZHONG N, et al. Highly efficient red-emitting carbon dots with gram-scale yield for bioimaging [J]. Langmuir, 2017, 33(44): 12635-12642. [Google Scholar] [Crossref]

11. LI D, JING P, SUN L, et al. Near‐infrared excitation/emission and multiphoton‐induced fluorescence of carbon dots [J]. Advanced materials, 2018, 30(13): 1705913. [Google Scholar] [Crossref]

12. HU C, LI M, QIU J, et al. Design and fabrication of carbon dots for energy conversion and storage [J]. Chemical Society Reviews, 2019, 48(8): 2315-2337. [Google Scholar] [Crossref]

13. LIU M L, CHEN B B, LI C M, et al. Carbon dots: synthesis, formation mechanism, fluorescence origin and sensing applications [J]. Green chemistry, 2019, 21(3): 449-471. [Google Scholar] [Crossref]

14. LIU J, LI R, YANG B. Carbon dots: a new type of carbon-based nanomaterial with wide applications [J]. ACS Central Science, 2020, 6(12): 2179. [Google Scholar] [Crossref]

15. MOLAEI M J. Carbon quantum dots and their biomedical and therapeutic applications: a review [J]. RSC advances, 2019, 9(12): 6460-6481. [Google Scholar] [Crossref]

16. WANG Y, HU A. Carbon quantum dots: synthesis, properties and applications [J]. Journal of Materials Chemistry C, 2014, 2(34): 6921-6939. [Google Scholar] [Crossref]

17. LI H, KANG Z, LIU Y, et al. Carbon nanodots: synthesis, properties and applications [J]. Journal of materials chemistry, 2012, 22(46): 24230-24253. [Google Scholar] [Crossref]

18. YE C, ZHANG D-S, CHEN B, et al. Quantum dots: Another choice to sensitize organic transformations [J]. Chemical Physics Reviews, 2023, 4(1). [Google Scholar] [Crossref]

19. DING H, YU S-B, WEI J-S, et al. Full-color light-emitting carbon dots with a surface-state-controlled luminescence mechanism [J]. ACS nano, 2016, 10(1): 484-491. [Google Scholar] [Crossref]

20. HOLA K, ZHANG Y, WANG Y, et al. Carbon dots—Emerging light emitters for bioimaging, cancer therapy and optoelectronics [J]. Nano Today, 2014, 9(5): 590-603. [Google Scholar] [Crossref]

21. JIANG K, SUN S, ZHANG L, et al. Red, green, and blue luminescence by carbon dots: full‐color emission tuning and multicolor cellular imaging [J]. Angewandte chemie, 2015, 127(18): 5450-5453. [Google Scholar] [Crossref]

22. YUAN F, YUAN T, SUI L, et al. Engineering triangular carbon quantum dots with unprecedented narrow bandwidth emission for multicolored LEDs [J]. Nature communications, 2018, 9(1): 2249. [Google Scholar] [Crossref]

23. SUN Y-P, ZHOU B, LIN Y, et al. Quantum-sized carbon dots for bright and colorful photoluminescence [J]. Journal of the American Chemical Society, 2006, 128(24): 7756-7757. [Google Scholar] [Crossref]

24. CHUNG Y J, KIM J, PARK C B. Photonic carbon dots as an emerging nanoagent for biomedical and healthcare applications [J]. ACS nano, 2020, 14(6): 6470-6497. [Google Scholar] [Crossref]

25. MITCHELL M J, BILLINGSLEY M M, HALEY R M, et al. Engineering precision nanoparticles for drug delivery [J]. Nature reviews drug discovery, 2021, 20(2): 101-124. [Google Scholar] [Crossref]

26. ZHAO Z, UKIDVE A, KIM J, et al. Targeting strategies for tissue-specific drug delivery [J]. Cell, 2020, 181(1): 151-167. [Google Scholar] [Crossref]

27. BEHZADI S, SERPOOSHAN V, TAO W, et al. Cellular uptake of nanoparticles: journey inside the cell [J]. Chemical society reviews, 2017, 46(14): 4218-4244. [Google Scholar] [Crossref]

28. HADJIDEMETRIOU M, KOSTARELOS K. Evolution of the nanoparticle corona [J]. Nature nanotechnology, 2017, 12(4): 288-290. [Google Scholar] [Crossref]

29. ROSENBLUM D, JOSHI N, TAO W, et al. Progress and challenges towards targeted delivery of cancer therapeutics [J]. Nature communications, 2018, 9(1): 1410. [Google Scholar] [Crossref]

30. SINDHWANI S, SYED A M, NGAI J, et al. The entry of nanoparticles into solid tumours [J]. Nature materials, 2020, 19(5): 566-575. [Google Scholar] [Crossref]

31. ALSHAER W, HILLAIREAU H, FATTAL E. Aptamer-guided nanomedicines for anticancer drug delivery [J]. Advanced drug delivery reviews, 2018, 134: 122-137. [Google Scholar] [Crossref]

32. DONAHUE N D, ACAR H, WILHELM S. Concepts of nanoparticle cellular uptake, intracellular trafficking, and kinetics in nanomedicine [J]. Advanced drug delivery reviews, 2019, 143: 68-96. [Google Scholar] [Crossref]

33. MANZANARES D, CEÑA V. Endocytosis: the nanoparticle and submicron nanocompounds gateway into the cell [J]. Pharmaceutics, 2020, 12(4): 371. [Google Scholar] [Crossref]

34. AGOSTINIS P, BERG K, CENGEL K A, et al. Photodynamic therapy of cancer: an update [J]. CA: a cancer journal for clinicians, 2011, 61(4): 250-281. [Google Scholar] [Crossref]

35. DOLMANS D E, FUKUMURA D, JAIN R K. Photodynamic therapy for cancer [J]. Nature reviews cancer, 2003, 3(5): 380-387. [Google Scholar] [Crossref]

36. LUCKY S S, SOO K C, ZHANG Y. Nanoparticles in photodynamic therapy [J]. Chemical reviews, 2015, 115(4): 1990-2042. [Google Scholar] [Crossref]

37. JAQUE D, MARTÍNEZ MAESTRO L, DEL ROSAL B, et al. Nanoparticles for photothermal therapies [J]. nanoscale, 2014, 6(16): 9494-9530. [Google Scholar] [Crossref]

38. GE J, JIA Q, LIU W, et al. Red‐emissive carbon dots for fluorescent, photoacoustic, and thermal theranostics in living mice [J]. Advanced Materials, 2015, 27(28): 4169-4177. [Google Scholar] [Crossref]

39. BAO X, YUAN Y, CHEN J, et al. In vivo theranostics with near-infrared-emitting carbon dots—highly efficient photothermal therapy based on passive targeting after intravenous administration [J]. Light: Science & Applications, 2018, 7(1): 91. [Google Scholar] [Crossref]

40. TANG Z, LIU Y, HE M, et al. Chemodynamic therapy: tumour microenvironment‐mediated Fenton and Fenton‐like reactions [J]. Angewandte Chemie International Edition, 2019, 58(4): 946-956. [Google Scholar] [Crossref]

41. HUO M, WANG L, CHEN Y, et al. Tumor-selective catalytic nanomedicine by nanocatalyst delivery [J]. Nature communications, 2017, 8(1): 357. [Google Scholar] [Crossref]

42. YANG B, CHEN Y, SHI J. Reactive oxygen species (ROS)-based nanomedicine [J]. Chemical reviews, 2019, 119(8): 4881-4985. [Google Scholar] [Crossref]

43. LIN L S, SONG J, SONG L, et al. Simultaneous Fenton‐like ion delivery and glutathione depletion by MnO2‐based nanoagent to enhance chemodynamic therapy [J]. Angewandte Chemie, 2018, 130(18): 4996-5000. [Google Scholar] [Crossref]

44. COSTLEY D, MC EWAN C, FOWLEY C, et al. Treating cancer with sonodynamic therapy: a review [J]. International Journal of Hyperthermia, 2015, 31(2): 107-117. [Google Scholar] [Crossref]

45. SON S, KIM J H, WANG X, et al. Multifunctional sonosensitizers in sonodynamic cancer therapy [J]. Chemical Society Reviews, 2020, 49(11): 3244-3261. [Google Scholar] [Crossref]

46. LIANG S, DENG X, MA P A, et al. Recent advances in nanomaterial‐assisted combinational sonodynamic cancer therapy [J]. Advanced Materials, 2020, 32(47): 2003214. [Google Scholar] [Crossref]

47. JIA Q, GE J, LIU W, et al. A magnetofluorescent carbon dot assembly as an acidic H2O2‐driven oxygenerator to regulate tumor hypoxia for simultaneous bimodal imaging and enhanced photodynamic therapy [J]. Advanced Materials, 2018, 30(13): 1706090. [Google Scholar] [Crossref]

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