Skip to main content Accessibility help

Pristine graphene quantum dots for detection of copper ions

  • Xiaofeng Liu (a1), Wei Gao (a1), Xuemei Zhou (a1) and Yuanyuan Ma (a1)


To selectively detect Cu2+ ions is very important for controlling daily intake of Cu2+ ions and monitoring numerous biological processes. Fluorescence spectroscopic technique is a useful one for detection of copper ions. Previous methods always involve the use of metal Cd-based quantum dots (QDs), which suffer to the photobleaching and subsequent release of toxic metal ions. Herein, a simple method has been developed to detect Cu2+ ions by using pristine graphene QDs. Graphene QDs are synthesized by chemical oxidation of pitch graphite fibers. Our results indicate the photoluminescence (PL) of as-synthesized graphene QDs could be quenched by a group of metal ions while adding biothiol cysteine can only cause the significant recovery of the PL of graphene QDs quenched by Cu2+ ions. Our approach provides an easy and environmental friendly method for detection of Cu2+ ions and has the potential for future practical applications.


Corresponding author

a) Address all correspondence to this author. e-mail:


Hide All
1. Kramer, R.: Fluorescent chemosensors for Cu2+ ions: Fast, selective, and highly sensitive. Angew. Chem., Int. Ed. 37, 772 (1998).
2. Georgopoulos, P.G., Roy, A., Yonone-Lioy, M.J., Opiekun, R.E., and Lioy, P.J.: Environmental copper: Its dynamics and human exposure issues. J. Toxicol. Environ. Health, B 4, 341 (2001).
3. Gaggelli, E., Kozlowski, H., Valensin, D., and Valensin, G.: Copper homeostasis and neurodegenerative disorders (Alzheimer's, prion, and Parkinson's diseases and amyotrophic lateral sclerosis). Chem. Rev. 106, 1995 (2006).
4. Jung, H.S., Kwon, P.S., Lee, J.W., Kim, J.I., Hong, C.S., Kim, J.W., Yan, S., Lee, J.Y., Lee, J.H., Joo, T., and Kim, J.S.: Coumarin-derived Cu2+-selective fluorescence sensor: Synthesis, mechanisms, and applications in living cells. J. Am. Chem. Soc. 131, 2008 (2009).
5. Chan, W.C.W., Maxwell, D.J., Gao, X.H., Bailey, R.E., Han, M.Y., and Nie, S.M.: Luminescent quantum dots for multiplexed biological detection and imaging. Curr. Opin. Biotechnol. 13, 40 (2002).
6. Basabe-Desmonts, L., Reinhoudt, D.N., and Crego-Calama, M.: Design of fluorescent materials for chemical sensing. Chem. Soc. Rev. 36, 993 (2007).
7. Gill, R., Zayats, M., and Willner, I.: Semiconductor quantum dots for bioanalysis. Angew. Chem., Int. Ed. 47, 7602 (2008).
8. Freeman, R. and Willner, I.: Optical molecular sensing with semiconductor quantum dots (QDs). Chem. Soc. Rev. 41, 4067 (2012).
9. Zhang, J., Li, B., Zhang, L.M., and Jiang, H.: An optical sensor for Cu(II) detection with upconverting luminescent nanoparticles as an excitation source. Chem. Commun. 48, 4860 (2012).
10. Xie, H.Y., Liang, H.G., Zhang, Z.L., Liu, Y., He, Z.K., and Pang, D.W.: Luminescent CdSe-ZnS quantum dots as selective Cu2+ probe. Spectrochim. Acta, Part A 60, 2527 (2004).
11. Fernandez-Arguelles, M.T., Jin, W.J., Costa-Fernandez, J.M., Pereiro, R., and Sanz-Medel, A.: Surface-modified CdSe quantum dots for the sensitive and selective determination of Cu(II) in aqueous solutions by luminescent measurements. Anal. Chim. Acta 549, 20 (2005).
12. Chan, Y.H., Chen, J.X., Liu, Q.S., Wark, S.E., Son, D.H., and Batteas, J.D.: Ultrasensitive copper(II) detection using plasmon-enhanced and photo-brightened luminescence of CdSe quantum dots. Anal. Chem. 82, 3671 (2010).
13. Wu, C.S., Oo, M.K.K., and Fan, X.D.: Highly sensitive multiplexed heavy metal detection using quantum-dot-labeled DNAzymes. ACS Nano 4, 5897 (2010).
14. Wang, G.L., Dong, Y.M., and Li, Z.J.: Metal ion (silver, cadmium and zinc ions) modified CdS quantum dots for ultrasensitive copper ion sensing. Nanotechnology 22, 085503 (2011).
15. Guo, C.X., Wang, J.L., Cheng, J., and Dai, Z.F.: Determination of trace copper ions with ultrahigh sensitivity and selectivity utilizing CdTe quantum dots coupled with enzyme inhibition. Biosens. Bioelectron. 36, 69 (2012).
16. Yang, P., Zhao, Y., Lu, Y., Xu, Q.Z., Xu, X.W., Dong, L., and Yu, S.H.: Phenol formaldehyde resin nanoparticles loaded with CdTe quantum dots: A fluorescence resonance energy transfer probe for optical visual detection of copper(II) ions. ACS Nano 5, 2147 (2011).
17. Shen, Y.Y., Li, L.L., Lu, Q., Ji, J., Fei, R., Zhang, J.R., Abdel-Halim, E.S., and Zhu, J.J.: Microwave-assisted synthesis of highly luminescent CdSeTe@ZnS–SiO2 quantum dots and their application in the detection of Cu(II). Chem. Commun. 48, 2222 (2012).
18. Sung, T.W. and Lo, Y.L.: Highly sensitive and selective sensor based on silica-coated CdSe/ZnS nanoparticles for Cu2+ ion detection. Sens. Actuator, B Chem. 165, 119 (2012).
19. Hardman, R.: A toxicologic review of quantum dots: Toxicity depends on physicochemical and environmental factors. Environ. Health Perspect. 114, 165 (2006).
20. Lewinski, N., Colvin, V., and Drezek, R.: Cytotoxicity of nanoparticles. Small 4, 26 (2008).
21. Klaine, S.J., Alvarez, P.J.J., Batley, G.E., Fernandes, T.F., Handy, R.D., Lyon, D.Y., Mahendra, S., McLaughlin, M.J., and Lead, J.R.: Nanomaterials in the environment: Behavior, fate, bioavailability, and effects. Environ. Toxicol. Chem. 27, 1825 (2008).
22. Reiss, P., Protiere, M., and Li, L.: Core/shell semiconductor nanocrystals. Small 5, 154 (2009).
23. Donega, C.M.: Synthesis and properties of colloidal heteronanocrystals. Chem. Soc. Rev. 40, 1512 (2011).
24. Fan, J.Y. and Chu, P.K.: Group IV nanoparticles: Synthesis, properties, and biological applications. Small 6, 2080 (2010).
25. Baker, S.N. and Baker, G.A.: Luminescent carbon nanodots: Emergent nanolights. Angew. Chem., Int. Ed. 49, 6726 (2010).
26. Liu, S., Tian, J.Q., Wang, L., Zhang, Y.W., Qin, X.Y., Luo, Y.L., Asiri, A.M., Al-Youbi, A.O., and Sun, X.P.: Hydrothermal treatment of grass: A low-cost, green route to nitrogen-doped, carbon-rich, photoluminescent polymer nanodots as an effective fluorescent sensing platform for label-free detection of Cu(II) ions. Adv. Mater. 24, 2037 (2012).
27. Qu, Q., Zhu, A., Shao, X., Shi, G., and Tian, Y.: Development of a carbon quantum dots-based fluorescent Cu2+ probe suitable for living cell imaging. Chem. Commun. 48, 5473 (2012).
28. Wang, F., Gu, Z., Lei, W., Wang, W., Xia, X., and Hao, Q.: Graphene quantum dots as a fluorescent sensing platform for highly efficient detection of copper (II) ions. Sens. Actuators, B Chem. 190, 516 (2014).
29. Cao, L., Meziani, M.J., Sahu, S., and Sun, X.P.: Photoluminescence properties of graphene versus other carbon nanomaterials. Acc. Chem. Res. 46, 171 (2013).
30. Yan, X., Cui, X., Li, B.S., and Li, L.S.: Large solution-processable graphene quantum dots as light absorbers for photovoltaics. Nano Lett. 10, 1869 (2010).
31. Zhuo, S.J., Shao, M.W., and Lee, S.T.: Upconversion and downconversion fluorescent graphene quantum dots: Ultrasonic preparation and photocatalysis. ACS Nano 6, 1059 (2012).
32. Gupta, V., Chaudhary, N., Srivastava, R., Sharma, G.D., Bhardwaj, R., and Cand, S.: Luminescent graphene quantum dots for organic photovoltaic devices. J. Am. Chem. Soc. 133, 9960 (2011).
33. Williams, K.J., Nelson, C.A., Yan, X., Li, L.S., and Zhu, X.Y.: Hot electron injection from graphene quantum dots to TiO2 . ACS Nano 7, 1388 (2013).
34. Li, Y., Zhao, Y., Cheng, H.H., Hu, Y., Shi, G.Q., Dai, L.M., and Qu, L.T.: Nitrogen-doped graphene quantum dots with oxygen-rich functional groups. J. Am. Chem. Soc. 134, 15 (2012).
35. Tang, L.B., Ji, R.B., Cao, X.K., Lin, J.Y., Jiang, H.X., Li, X.M., Teng, K.S., Luk, C.M., Zeng, S.J., Hao, J.H., and Lau, S.P.: Deep ultraviolet photoluminescence of water-soluble self-passivated graphene quantum dots. ACS Nano 6, 5102 (2012).
36. Pan, D.Y., Zhang, J.C., Li, Z., and Wu, M.H.: Hydrothermal route for cutting graphene sheets into blue-luminescent graphene quantum dots. Adv. Mater. 22, 734 (2010).
37. Peng, J., Gao, W., Gupta, B.K., Liu, Z., Romero-Aburto, R., Ge, L.H., Song, L., Alemany, L.B., Zhan, X.B., Gao, G.H., Vithayathil, S.A., Kaipparettu, B.A., Marti, A.A., Hayashi, T., Zhu, J.J., and Ajayan, P.M.: Graphene quantum dots derived from carbon fibers. Nano Lett. 12, 844 (2012).
38. Liu, R.L., Wu, D.Q., Feng, X.L., and Mullen, K.: Bottom-up fabrication of photoluminescent graphene quantum dots with uniform morphology. J. Am. Chem. Soc. 133, 15221 (2011).
39. Lee, J., Kim, K., Park, W.I., Kim, B.H., Park, J.H.. Kim, T.H., Bong, S., Kim, C.H., Chae, G., Jun, M., Hwang, Y., Jung, Y.S., and Jeon, S.: Uniform graphene quantum dots patterned from self-assembled silica nanodots. Nano Lett. 12, 6078 (2012).
40. Luo, Z.T., Lu, Y., Somers, L.A., and Johnson, A.T.C.: High yield preparation of macroscopic graphene oxide membranes. J. Am. Chem. Soc. 131, 898 (2009).
41. Sun, Y.P., Zhou, B., Lin, Y., Wang, W., Fernando, K.A.S., Pathak, P., Meziani, M.J., Harruff, B. A., Wang, X., Wang, H.F., Luo, P.J.G., Yang, H., Kose, M.E., Chen, B.L., Veca, L.M., and Xie, S.Y.: Quantum-sized carbon dots for bright and colorful photoluminescence. J. Am. Chem. Soc. 126, 7756 (2006).
42. Yang, S.T., Cao, L., Luo, P.G.J., Lu, F.S., Wang, X., Wang, H.F., Meziani, M.J., Liu, Y.F., Qi, G., and Sun, X.P.: Carbon dots for optical imaging in vivo. J. Am. Chem. Soc. 131, 11308 (2009).
43. Liu, H.B., Zhu, H.N., Eggers, D.K., Nersissian, A.M., Faull, K.F., Goto, J.J., Ai, J.Y., Sanders-Loehr, J., Gralla, E.B., and Valentine, J.S.: Copper (2+) binding to the surface residue cysteine 111 of His46Arg human copper-zinc superoxide dismutase, a familial amyotrophic lateral sclerosis mutant. Biochemistry 39, 8125 (2000).
44. Rigo, A., Corazza, A., Paolo, M.L., Rossetto, M., Ugolini, R., and Scarpa, M.: Interaction of copper with cysteine: Stability of cuprous complexes and catalytic role of cupric ions in anaerobic thiol oxidation. J. Inorg. Biochem. 98, 1495 (2004).


Type Description Title
Supplementary materials

Liu et al. supplementary material
Supplementary figures

 Word (225 KB)
225 KB

Pristine graphene quantum dots for detection of copper ions

  • Xiaofeng Liu (a1), Wei Gao (a1), Xuemei Zhou (a1) and Yuanyuan Ma (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed