• The carbon quantum dots-disulfiram conjugate via disulfide bonding for targeted drug delivery
  • Mohamad Mahani,1,* Mohadese Panaei,2 Faeze Khakbaz,3 Mehdi Yousefian,4
    1. Department of Chemistry, Faculty of Chemistry and Chemical Engineering, Graduate University of Advanced Technology, Kerman, Iran.
    2. Department of Chemistry, Faculty of Chemistry and Chemical Engineering, Graduate University of Advanced Technology, Kerman, Iran.
    3. Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran
    4. Department of Chemistry, Faculty of Chemistry and Chemical Engineering, Graduate University of Advanced Technology, Kerman, Iran.


  • Introduction: Disulfiram (DSF) has been used as an anti-alcoholism drug for over 60 years [1]. Plenty researches have shown evidence of promising anticancer efficacy of this agent for treatment of wide range of cancers [2]. nanoparticles can improve DSF solubility, isolate it from labile environment and enhance its accumulation in the tumor tissue, which altogether result in a better anticancer efficacy [3]. As a group of newly emerged fluorescent nanomaterials, Carbon quantum dots (CQDs) have shown tremendous potential as versatile nanomaterials for a wide range of applications, including biosensing, bioimaging and drug delivery [4]. CQDs is an important carbon nano-material with dimensions less than 10 nm, comprising of amorphous or crystalline center with an oxidized carboxylic carbon surface [5]. In this paper, the CQDs-DSF conjugate was investigated for targeted drug delivery.
  • Methods: First citric acid and urea were dissolved in DMSO. This solution was transferred into autoclave and incubated at 160c for 4 h in an oven. The resulting solution was dark brown in color due to the formation of the CQDs. Then CQDs were diluted with distilled water, DTT was added and stirred to activate the sulfur functional group. The DSF was added to sulfur functionalized CQDs and stirred for 24 h.
  • Results: The absorption spectra of CQDs were recorded in the UV-Vis region. The absorption peak at nearly 250 nm can be attributed to the ᴨ -ᴨ* transitions and the peak observed at 350 nm can be attributed to n-ᴨ* transitions. The absorption spectrum of DSF was also observed at 280 nm. The highest fluorescence emission of CQDs intensity is related to the emission wavelength of 460 nm in excitation wavelength of 365 nm. The particle size of CQDs was obtained 3 nm .The surface functional groups of the CQDs were detected using the FTIR. A broad band is observed from 2800 to 3500 cm−1, showing the presence of N−H and O−H bonds and thereby confirming the presence of N in the CQDs. The sharp peak at 1632 cm−1 can be due to the c=o groups. The peak around 1205cm-1 is ascribed to the C–O, C–N, and C–S bonds. The percent loading of the drug was calculated 34%. The release drug in the presence of glutathione (GSH) at pH=5.4 was show an upward trend and reached 80% after 24 h In this study CQD was exhibit no cytotoxic effect and free DSF was show lower cell viability effect. The cytotoxicity of CQDs-DSF was lower in comparison with CQDs-DSF-GSH.
  • Conclusion: In this study, the solvothermal method was used to synthesize CQDs. The CQDs were biocompatible because it showed no cytotoxicity in MCF-7 cells so can be used as an efficient nanocarrier. With increasing concentration of CQD-DSF cell death also increases, with the difference that an increase in cell death is more observed in the presence of glutathione because glutathione breaks disulfide bonds and releases more drug. Glutathione amount is different in normal and cancer cells. As a result, targeted drug delivery can be performed in the presence of glutathione.
  • Keywords: Carbon quantum dot, Disulfiram, Drug delivery