Journal of Fluorescence

, Volume 19, Issue 4, pp 723–731 | Cite as

Mechanistic Aspects of Quantum Dot Based Probing of Cu (II) Ions: Role of Dendrimer in Sensor Efficiency

  • Srabanti Ghosh
  • Amiya Priyam
  • Subhash C. Bhattacharya
  • Abhijit Saha
Original Paper


Selective quenching of luminescence of quantum dots (QDs) by Cu2+ ions vis-à-vis other physiologically relevant cations has been reexamined. In view of the contradiction regarding the mechanism, we have attempted to show why Cu2+ ions quench QD-luminescence by taking CdS and CdTe QDs with varying surface groups. A detailed study of the solvent effect and also size dependence on the observed luminescence has been carried out. For a 13% decrease in particle diameter (4.3 nm →3.7 nm), the quenching constant increased by a factor of 20. It is established that instead of surface ligands of QDs, conduction band potential of the core facilitates the photo-induced reduction of Cu (II) to Cu (I) thereby quenching the photoluminescence. Taking the advantage of biocompatibility of dendrimer and its high affinity towards Cu2+ ions, we have followed interaction of Cu2+-PAMAM and also dendrimer with the CdTe QDs. Nanomolar concentration of PAMAM dendrimer was found to quench the luminescence of CdTe QDs. In contrast, Cu2+-PAMAM enhanced the fluorescence of CdTe QDs and the effect has been attributed to the binding of Cu2+-PAMAM complex to the CdTe particle surface. The linear portion of the enhancement plot due to Cu2+-PAMAM can be used for determination of Cu2+ ions with detection limit of 70 nM.


CdTe Nanoparticles Cu2+ions PAMAM dendrimer Photoluminescence (PL) 



The authors wish to thank Chemical Science Division, Saha Institute of Nuclear Physics, Kolkata for help in fluorescence lifetime measurement. One of the authors (A.P.) is thankful to University Grants Commission, Govt. of India, for the award of Senior Research Fellowship.


  1. 1.
    Chan WCW, Nie SM (1998) Quantum dot bioconjugates for ultrasensitive nonisotopic detection. Science 281:2016–2018 doi: 10.1126/science.281.5385.2016 PubMedCrossRefGoogle Scholar
  2. 2.
    Bruchez M Jr, Moronne M, Gin P, Weiss S, Alivisators AP (1998) Nanocrystals as fluorescent biological labels. Science 281:2013–2016 doi: 10.1126/science.281.5385.2013 PubMedCrossRefGoogle Scholar
  3. 3.
    Goldman ER, Clapp AR, Anderson GP, Uyeda HT, Mauro JM, Medintz IL, Mattoussi H (2004) Multiplexed toxin analysis using four colors of quantum dot fluororeagents. Anal. Chem. 76:684–688 doi: 10.1021/ac035083r PubMedCrossRefGoogle Scholar
  4. 4.
    Sutherland AJ (2002) Quantum dots as luminescent probes in biological systems. Curr. Opin. Solid State Mater. Sci 6:365–370 doi: 10.1016/S1359-0286(02)00081-5 CrossRefGoogle Scholar
  5. 5.
    Msttoussi H, Mauro JM, Goldman ER, Anderson GP, Sundar VC, Mikulec FV, Bawendi MG (2000) Self-Assembly of CdSe-ZnS Quantum Dot bioconjugate using an engineered recombinant protein. J. Am. Chem. Soc. 122:12142–12150 doi: 10.1021/ja002535y CrossRefGoogle Scholar
  6. 6.
    Wachnik A (2006) The physiological role of copper and the problems of copper nutritional deficiency. Food 32:755–765Google Scholar
  7. 7.
    Issarov A, Chrysochoos J (1997) Surface effects on regularities of electron transfer in CdS and CdS/CuxS colloids as studied by photoluminescence quenching. Langmuir 13:3142–3149 doi: 10.1021/la960985r CrossRefGoogle Scholar
  8. 8.
    Moore DE, Patel K (2001) Q-CdS photoluminescence activation on Zn2+ and Cd2+ salt introduction. Langmuir 17:2541–2544 doi: 10.1021/la001416t CrossRefGoogle Scholar
  9. 9.
    Chatterjee A, Priyam A, Bhattacharya SC, Saha A (2007) pH dependent interaction of biofunctionalized CdS nanoparticles with nucleotides and nucleobases. J. Lumin. 126:764–770 doi: 10.1016/j.jlumin.2006.11.010 CrossRefGoogle Scholar
  10. 10.
    Priyam A, Chatterjee A, Das SK, Saha A (2005) Size dependent interaction of biofunctionalized CdS nanoparticles with tyrosine at different pH. Chem. Commun. (Camb.) 32:4122–4124 doi: 10.1039/b505960g CrossRefGoogle Scholar
  11. 11.
    Chen YF, Rosenzweig Z (2002) Luminescence CdS quantum dots as selective ion probes. Anal. Chem. 74:5132–5138 doi: 10.1021/ac0258251 PubMedCrossRefGoogle Scholar
  12. 12.
    Liang JG, Ai XP, He ZK, Pang DW (2004) Functionalized CdSe quantum dots as selective silver ion chemodosimeter. Analyst (Lond.) 129:619–622 doi: 10.1039/b317044f CrossRefGoogle Scholar
  13. 13.
    Li J, Bao D, Hong X, Li D, Li J, Bao Y, Li T (2005) Luminescent CdTe quantum dots and nanorods as metal ion probes. Colloid Surf A Physicochemical Eng Aspects. 257–258:267–271 doi: 10.1016/j.colsurfa.2004.10.034 CrossRefGoogle Scholar
  14. 14.
    Torrado A, Walkup GK, Imperiali B (1998) Exploiting polypeptide motifs for the design of selective Cu (II) ion chemosensors. J. Am. Chem. Soc. 120:609–617 doi: 10.1021/ja973357k CrossRefGoogle Scholar
  15. 15.
    Klein G, Kaufman D, Schuch S, Raymond IL (2001) A fluorescent metal sensor based on macrocyclic chelation. Chem. Commun. (Camb.). 561–562 doi: 10.1039/b100535i
  16. 16.
    Prodi L, Bollrtta F, Montalti M, Zaccheroni N (2001) Dansylated polyamines as fluorescent sensors for metal ions: photophysical properties and stability of Copper(II) complexes in solution. Helv. Chim. Acta 84:608–706 doi: 10.1002/1522-2675(20010321)84:3<690::AID-HLCA690>3.0.CO;2-L CrossRefGoogle Scholar
  17. 17.
    Tomalia DA, Becker H, Dewald J, Hall M, Kallos G, Martin S, Roeck J, Ryder J, Smith P (1985) A new class of polymers—starburst-dendritic macromolecules Polymer. Polym. J. 17:117–132 doi: 10.1295/polymj.17.117 CrossRefGoogle Scholar
  18. 18.
    Tomalia DA, Naylor AN, Goddard WA III (1990) Starburst Dendrimers: Molecular-Level Control of Size, Shape, Surface Chemistry, Topology, and Flexibility from Atoms to Macroscopic Matter. Angew. Chem. Int. Ed. Engl. 29:138–175 doi: 10.1002/anie.199001381 CrossRefGoogle Scholar
  19. 19.
    Diallo MS, Balogh L, Shafagati A, Johnson JH Jr, Wadder WA III, Tomalia DA (1999) Poly (amidoamine) Dendrimers: a new class of high capacity chelating agents for Cu(II) Ions. Environ. Sci. Technol. 33:820–828 doi: 10.1021/es980521a CrossRefGoogle Scholar
  20. 20.
    Pellechia PJ, Gao J, Gu Y, Ploehn J, Murphy CJ (2004) Platinum ion uptake by dendrimers: an NMR and AFM study. Inorg. Chem. 43:1421–4124 doi: 10.1021/ic035127e PubMedCrossRefGoogle Scholar
  21. 21.
    Tang B, Nui J, Yu C, Zhuo L, Ge J (2005) Highly luminescent water-soluble CdTe nanowires as fluorescent probe to detect copper (II). Chem. Commun. (Camb.) 4184–4186 doi: 10.1039/b502978c
  22. 22.
    Priyam A, Chaterjee A, Bhattacharya SC, Saha A (2007) Surface-functionalized Cadmium chalcogenide nanocrystals: a spectroscopic investigation of growth and photoluminescence. J. Cryst. Growth 304:416–426 doi: 10.1016/j.jcrysgro.2007.02.026 CrossRefGoogle Scholar
  23. 23.
    Sapra S, Sarma DD (2004) Evolution of the electronic structure with size in II-VI semiconductor nanocrystals. Phys. Rev. B 69:125304–125310 doi: 10.1103/PhysRevB.69.125304 CrossRefGoogle Scholar
  24. 24.
    Aich S, Raha C, Basu S (1997) Characterization of the triplet charge-transfer state of 4-amino-N-methylphthalimide in aprotic and protic media by laser flash photolysis. J. Chem. Soc., Faraday Trans. 93:2991–2996 doi: 10.1039/a701291h CrossRefGoogle Scholar
  25. 25.
    Talapin DV, Rogach AL, Shevchenko EV, Kornowski A, Haase M, Weller H (2002) Dynamic distribution of growth rates within the ensembles of colloidal II-VI and III-V semiconductor nanocrystals as a factor governing their photoluminescence efficiency. J. Am. Chem. Soc. 124:5782–5790 doi: 10.1021/ja0123599 PubMedCrossRefGoogle Scholar
  26. 26.
    Lakowicz JR (1999) Principles of Fluorescence Spectroscopy, 2nd edn. Kluwer Academic/Plenum, New York, pp 52–53Google Scholar
  27. 27.
    Wilkinson F, Abdel-Shafi AA (1999) Mechanism of quenching of triplet states by molecular oxygen: biphenyl derivatives in different solvents. J. Phys. Chem. A 103:5425–5435 doi: 10.1021/jp9907995 CrossRefGoogle Scholar
  28. 28.
    Rajh T (1993) Synthesis and characterization of surface-modified colloidal cadmium telluride quantum dots. J. Phys. Chem. 97:11999–12003 doi: 10.1021/j100148a026 CrossRefGoogle Scholar
  29. 29.
    Matusumoto H, Matsunaga T, Sakata T, Mori H, Yoneyama H (1995) Size dependent fluorescence quenching of CdS nanocrystals caused by TiO2 colloids as a potential-variable quencher. Langmuir 11:4283–4287 doi: 10.1021/la00011a019 CrossRefGoogle Scholar
  30. 30.
    Haram SK, Quinin BM, Bard AJ (2001) Electrochemistry of CdS nanoparticles:a correlation between optical and electrochemical band gap. J. Am. Chem. Soc. 123:8860–8888 doi: 10.1021/ja0158206 PubMedCrossRefGoogle Scholar
  31. 31.
    Hengglein A (1981) Small-particle research: physicochemical properties of extremely small colloidal metal and semiconductor. Chem. Rev. 89:1861–18 doi: 10.1021/cr00098a010 CrossRefGoogle Scholar
  32. 32.
    Li QF, Liu SH, Zhang HY, Chen XG, Hu ZD (2001) Microdetermination of proteins by enhanced resonance light scattering spectroscopy of Acetylchlorophosphonazo. Anal. Lett. 34:1133–1134 doi: 10.1081/AL-100104959 CrossRefGoogle Scholar
  33. 33.
    Brey W (1978) Physical Chemistry and its Biological Applications. Academic, New YorkGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Srabanti Ghosh
    • 1
  • Amiya Priyam
    • 1
  • Subhash C. Bhattacharya
    • 2
  • Abhijit Saha
    • 1
  1. 1.UGC-DAE Consortium for Scientific ResearchKolkata Centre, III/LB-8BidhananagarIndia
  2. 2.Department of ChemistryJadavpur UniversityKolkataIndia

Personalised recommendations