Analytical and Bioanalytical Chemistry

, Volume 410, Issue 24, pp 6331–6336 | Cite as

Highly passivated phosphorous and nitrogen co-doped carbon quantum dots and fluorometric assay for detection of copper ions

  • Khalid M. OmerEmail author
Research Paper


Carbon quantum dots are becoming powerful fluorophore materials for metal ion analysis. Here, highly passivated green phosphorous and nitrogen co-doped carbon quantum dots (C-dots) were prepared using low-temperature carbonization route. Strong green fluorescence emission around 490 nm and excitation wavelength independent C-dots were obtained. Morphological, surface, and optical properties of the C-dots were characterized. Fluorescence emission of C-dots was quenched selectively by copper ions and restored by adding copper chelators, such as EDTA and sulfide ions. Thus, C-dots were successfully used for direct determination of copper ions. Detection limit as low as 1.5 nM (s/n = 3) was achieved for copper ions. Such a low detection limit is very significant for metal analysis using our proposed facile method and low-cost substrates. Experimental results showed that the prepared C-dots demonstrated high sensitivity and selectivity for Cu2+ ion detection and the method is robust and rugged.

Graphical abstract


Carbon quantum dots Copper Fluorimetric assay Phosphorous and nitrogen-doped carbon quantum dots 



The author thanks Dr. Hugo Celio for his help with the XPS measurement at the University of Texas at Austin.

Funding information

The author thanks the University of Sulaimani and Ministry of Higher Education and Scientific Research in Kurdistan for supporting the work.

Compliance with ethical standards

Conflict of interest

The author declares that there is no conflict of interest.

Supplementary material

216_2018_1242_MOESM1_ESM.pdf (472 kb)
ESM 1 (PDF 472 kb)


  1. 1.
    Szpunar J, Bettmer J, Robert M, Chassaigne H, Cammann K, Lobinski R, et al. Validation of the determination of copper and zinc in blood plasma and urine by ICP MS with cross-flow and direct injection nebulization. Talanta. 1997;44(8):1389–96.CrossRefPubMedGoogle Scholar
  2. 2.
    Carvalho RNCS, Brito GB, Korn MGA, Teixeira JSR, Dias FS, Dantas AF, et al. Multi-element determination of copper, iron, nickel, manganese, lead and zinc in environmental water samples by ICP OES after solid phase extraction with a C18 cartridge loaded with 1-(2-pyridylazo)-2-naphthol. Anal Methods. 2015;7(20):8714–9.CrossRefGoogle Scholar
  3. 3.
    Kojima I, Nakashima N, Isoyama H, Uchida T, Iida C. Determination of copper by flame atomic absorption spectrometry using discrete nebulisation of a carbon tetrachloride extract. J Anal At Spectrom. 1988;3(4):583–6.CrossRefGoogle Scholar
  4. 4.
    Pozzatti M, Borges AR, Dessuy MB, Vale MGR, Welz B. Determination of cadmium, chromium and copper in vegetables of the Solanaceae family using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis. Anal Methods. 2017;9(2):329–37.CrossRefGoogle Scholar
  5. 5.
    Xie N, Ma W, Gao H, Sun D. Simultaneous determination of lead and copper by anodic stripping voltammetry using a poly (L-glutamic acid) modified electrode. 2017.Google Scholar
  6. 6.
    Jedryczko D, Pohl P, Welna M. Determination of the total cadmium, copper, lead and zinc concentrations and their labile species fraction in apple beverages by flow-through anodic stripping chronopotentiometry. Food Chem. 2017;225:220–9.CrossRefPubMedGoogle Scholar
  7. 7.
    Guo Z, Luo X-k, Li Y-h, Zhao Q-N, Li M-m, Zhao Y-t, et al. Simultaneous determination of trace Cd (II), Pb (II) and Cu (II) by differential pulse anodic stripping voltammetry using a reduced graphene oxide-chitosan/poly-l-lysine nanocomposite modified glassy carbon electrode. J Colloid Interface Sci. 2017;490:11–22.CrossRefPubMedGoogle Scholar
  8. 8.
    Nanoparticles FC. Synthesis, characterization, and bioimaging application ray, SC; Saha, Arindam; Jana, Nikhil R.; Sarkar. J Phys Chem C. 2009;113(43):18546–51.CrossRefGoogle Scholar
  9. 9.
    Li H, Kang Z, Liu Y, Lee S-T. Carbon nanodots: synthesis, properties and applications. J Mater Chem. 2012;22(46):24230–53.CrossRefGoogle Scholar
  10. 10.
    Baker SN, Baker GA. Luminescent carbon nanodots: emergent nanolights. Angew Chem Int Ed. 2010;49(38):6726–44.CrossRefGoogle Scholar
  11. 11.
    Fernando KS, Sahu S, Liu Y, Lewis WK, Guliants EA, Jafariyan A, et al. Carbon quantum dots and applications in photocatalytic energy conversion. ACS Appl Mater Interfaces. 2015;7(16):8363–76.CrossRefPubMedGoogle Scholar
  12. 12.
    Banerjee S, Pillai SC, Falaras P, O'Shea KE, Byrne JA, Dionysiou DD. New insights into the mechanism of visible light photocatalysis. J Phys Chem Lett. 2014;5(15):2543–54.CrossRefPubMedGoogle Scholar
  13. 13.
    Sun Y-P, Zhou B, Lin Y, Wang W, Fernando KS, Pathak P, et al. Quantum-sized carbon dots for bright and colorful photoluminescence. J Am Chem Soc. 2006;128(24):7756–7.CrossRefPubMedGoogle Scholar
  14. 14.
    Li L, Wu G, Yang G, Peng J, Zhao J, Zhu J-J. Focusing on luminescent graphene quantum dots: current status and future perspectives. Nano. 2013;5(10):4015–39.Google Scholar
  15. 15.
    Gao X, Du C, Zhuang Z, Chen W. Carbon quantum dot-based nanoprobes for metal ion detection. J Mater Chem C. 2016;4(29):6927–45.CrossRefGoogle Scholar
  16. 16.
    Yu J, Fan F-RF, Pan S, Lynch VM, Omer KM, Bard AJ. Spontaneous formation and electrogenerated chemiluminescence of tris(bipyridine) Ru(II) derivative nanobelts. J Am Chem Soc. 2008;130(23):7196–7.CrossRefPubMedGoogle Scholar
  17. 17.
    Omer KM, Mohammad SJ, Raheem SJ. Solventless synthesis of a Schiff base that forms highly fluorescent organic nanoparticles exhibiting aggregation-induced emission in aqueous media. J Exp Nanosci. 2016;11(15):1184–92.CrossRefGoogle Scholar
  18. 18.
    Omer KM, Ku S-Y, Cheng J-Z, Chou S-H, Wong K-T, Bard AJ. Electrochemistry and electrogenerated chemiluminescence of a spirobifluorene-based donor (triphenylamine)−acceptor (2,1,3-benzothiadiazole) molecule and its organic nanoparticles. J Am Chem Soc. 2011;133(14):5492–9.CrossRefPubMedGoogle Scholar
  19. 19.
    Omer KM, Ku S-Y, Chen Y-C, Wong K-T, Bard AJ. Electrochemical behavior and electrogenerated chemiluminescence of star-shaped D−A compounds with a 1,3,5-triazine core and substituted fluorene arms. J Am Chem Soc. 2010;132(31):10944–52.CrossRefPubMedGoogle Scholar
  20. 20.
    Omer KM, Bard AJ. Electrogenerated chemiluminescence of aromatic hydrocarbon nanoparticles in an aqueous solution. J Phys Chem C. 2009;113(27):11575–8.CrossRefGoogle Scholar
  21. 21.
    Omer KM, Mohammad NN, Baban SO, Hassan AQ. Carbon nanodots as efficient photosensitizers to enhance visible-light driven photocatalytic activity. J Photochem Photobiol A Chem. 2018;364:53–8.CrossRefGoogle Scholar
  22. 22.
    Ju J, Zhang R, Chen W. Photochemical deposition of surface-clean silver nanoparticles on nitrogen-doped graphene quantum dots for sensitive colorimetric detection of glutathione. Sensors Actuators B Chem. 2016;228:66–73.CrossRefGoogle Scholar
  23. 23.
    Zhang R, Chen W. Nitrogen-doped carbon quantum dots: facile synthesis and application as a “turn-off” fluorescent probe for detection of Hg2+ ions. Biosens Bioelectron. 2014;55:83–90.CrossRefPubMedGoogle Scholar
  24. 24.
    Ju J, Chen W. In situ growth of surfactant-free gold nanoparticles on nitrogen-doped graphene quantum dots for electrochemical detection of hydrogen peroxide in biological environments. Anal Chem. 2015;87(3):1903–10.CrossRefPubMedGoogle Scholar
  25. 25.
    Wang C, Hu T, Wen Z, Zhou J, Wang X, Wu Q, et al. Concentration-dependent color tunability of nitrogen-doped carbon dots and their application for iron(III) detection and multicolor bioimaging. J Colloid Interface Sci. 2018;521:33–41.CrossRefPubMedGoogle Scholar
  26. 26.
    Tang Y, Su Y, Yang N, Zhang L, Lv Y. Carbon nitride quantum dots: a novel chemiluminescence system for selective detection of free chlorine in water. Anal Chem. 2014;86(9):4528–35.CrossRefPubMedGoogle Scholar
  27. 27.
    Omer KM, Hassan AQ. Chelation-enhanced fluorescence of phosphorus doped carbon nanodots for multi-ion detection. Microchim Acta. 2017;184(7):2063–71.CrossRefGoogle Scholar
  28. 28.
    Yao J, Zhang K, Zhu H, Ma F, Sun M, Yu H, et al. Efficient ratiometric fluorescence probe based on dual-emission quantum dots hybrid for on-site determination of copper ions. Anal Chem. 2013;85(13):6461–8.CrossRefPubMedGoogle Scholar
  29. 29.
    Yan Y, Yu H, Zhang K, Sun M, Zhang Y, Wang X, et al. Dual-emissive nanohybrid of carbon dots and gold nanoclusters for sensitive determination of mercuric ions. Nano Res. 2016;9(7):2088–96.CrossRefGoogle Scholar
  30. 30.
    Ju J, Chen W. Synthesis of highly fluorescent nitrogen-doped graphene quantum dots for sensitive, label-free detection of Fe (III) in aqueous media. Biosens Bioelectron. 2014;58:219–25.CrossRefPubMedGoogle Scholar
  31. 31.
    Gao X, Lu Y, Zhang R, He S, Ju J, Liu M, et al. One-pot synthesis of carbon nanodots for fluorescence turn-on detection of Ag+ based on the Ag+-induced enhancement of fluorescence. J Mater Chem C. 2015;3(10):2302–9.CrossRefGoogle Scholar
  32. 32.
    Sun M, Yu H, Zhang K, Zhang Y, Yan Y, Huang D, et al. Determination of gaseous sulfur dioxide and its derivatives via fluorescence enhancement based on cyanine dye functionalized carbon nanodots. Anal Chem. 2014;86(19):9381–5.CrossRefPubMedGoogle Scholar
  33. 33.
    Albrecht C, Lakowicz JR. Principles of fluorescence spectroscopy. Anal Bioanal Chem. 2008;390(5):1223–4.CrossRefGoogle Scholar
  34. 34.
    Williams ATR, Winfield SA, Miller JN. Relative fluorescence quantum yields using a computer-controlled luminescence spectrometer. Analyst. 1983;108(1290):1067–71.CrossRefGoogle Scholar
  35. 35.
    Liu D, Qu F, Zhao X, You J. Generalized one-pot strategy enabling different surface functionalizations of carbon nanodots to produce dual emissions in alcohol–water binary systems. J Phys Chem C. 2015;119(31):17979–87.CrossRefGoogle Scholar
  36. 36.
    Xu Y, Wu M, Liu Y, Feng XZ, Yin XB, He XW, et al. Nitrogen-doped carbon dots: a facile and general preparation method, photoluminescence investigation, and imaging applications. Chem Eur J. 2013;19(7):2276–83.CrossRefPubMedGoogle Scholar
  37. 37.
    Bao L, Zhang ZL, Tian ZQ, Zhang L, Liu C, Lin Y, et al. Electrochemical tuning of luminescent carbon nanodots: from preparation to luminescence mechanism. Adv Mater. 2011;23(48):5801–6.CrossRefPubMedGoogle Scholar
  38. 38.
    Ding H, Du F, Liu P, Chen Z, Shen J. DNA–carbon dots function as fluorescent vehicles for drug delivery. ACS Appl Mater Interfaces. 2015;7(12):6889–97.CrossRefPubMedGoogle Scholar
  39. 39.
    Jin X, Sun X, Chen G, Ding L, Li Y, Liu Z, et al. pH-sensitive carbon dots for the visualization of regulation of intracellular pH inside living pathogenic fungal cells. Carbon. 2015;81:388–95.CrossRefGoogle Scholar
  40. 40.
    Hart JN, May PW, Allan NL, Hallam KR, Claeyssens F, Fuge GM, et al. Towards new binary compounds: synthesis of amorphous phosphorus carbide by pulsed laser deposition. J Solid State Chem. 2013;198:466–74.CrossRefGoogle Scholar
  41. 41.
    Gong X, Lu W, Liu Y, Li Z, Shuang S, Dong C, et al. Low temperature synthesis of phosphorous and nitrogen co-doped yellow fluorescent carbon dots for sensing and bioimaging. J Mater Chem B. 2015;3(33):6813–9.CrossRefGoogle Scholar
  42. 42.
    Gong X, Zhang Q, Gao Y, Shuang S, Choi MM, Dong C. Phosphorus and nitrogen dual-doped hollow carbon dot as a nanocarrier for doxorubicin delivery and biological imaging. ACS Appl Mater Interfaces. 2016;8(18):11288–97.CrossRefPubMedGoogle Scholar
  43. 43.
    Li X, Zhang S, Kulinich SA, Liu Y, Zeng H. Engineering surface states of carbon dots to achieve controllable luminescence for solid-luminescent composites and sensitive Be 2+ detection. Sci Rep. 2014;4:4976.CrossRefPubMedCentralGoogle Scholar
  44. 44.
    Umberger JQ, LaMer VK. The kinetics of diffusion controlled molecular and ionic reactions in solution as determined by measurements of the quenching of fluorescence1,2. J Am Chem Soc. 1945;67(7):1099–109.CrossRefGoogle Scholar
  45. 45.
    Dong Y, Wang R, Li G, Chen C, Chi Y, Chen G. Polyamine-functionalized carbon quantum dots as fluorescent probes for selective and sensitive detection of copper ions. Anal Chem. 2012;84(14):6220–4.CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Chemistry, College of ScienceUniversity of SulaimaniSulaimaniIraq
  2. 2.Komar University of Science and TechnologySulaimaniIraq

Personalised recommendations