Electrochemical detection of copper ions leached from CuO nanoparticles in saline buffers and biological media using a gold wire working electrode

  • Carlo Baldisserri
  • Anna Luisa Costa
Research Paper


We performed explorative cyclic voltammetry in phosphate-buffered saline buffers, Dulbecco’s modified Eagle’s medium (DMEM), and fetal bovine serum-added DMEM using Au wire as working electrode, both in the absence and in the presence of known nominal concentrations of Cu2+ ions or 15 nm CuO nanoparticles. Addition of either Cu2+ ions or aqueous suspension of CuO nanoparticles caused a single anodic peak to appear in the double-layer region of all three pristine media. The height of the anodic peak was found to increase in a monotonic fashion vs. Cu2+ concentration in Cu2+-added media, and versus time since CuO addition in CuO-added media. Stepwise addition of glycine to Cu2+-added phosphate-buffered saline buffer caused an increasing cathodic shift of the anodic peak accompanied by decreasing peak currents. Results indicate that preparing Cu2+-free suspensions of CuO nanoparticles in such media is difficult, owing to the presence of leached copper ions. The implications on results of experiments in which CuO nanoparticle-added biological media are used as cell culture substrates are discussed. Literature data on the interactions between Cu2+ ions, dissolved carbon dioxide in aqueous CuO suspensions, and amino acids present in such media are compared to our results.


CuO nanoparticles DMEM Cyclic voltammetry Ion leaching Au electrode Sensor 



Funding from the Sustainable Nanotechnologies (SUN)—2013-2017—FP7-NMP-2013-LARGE-7-604305SUN Project is gratefully acknowledged. We also wish to thank Prof. Angelo Casagrande, Associated Professor, Department of Industrial Engineering, University of Bologna, for granting the use of the Autolab electrochemical workstation.


  1. Altun Ö, Bilcen S (2010) Spectroscopic characterization of Cu(II) complexes of l-phenylalanine and d,l-tryptophan. Spectrochim Acta A 75(2):789–793CrossRefGoogle Scholar
  2. Arulsamy N, Rao CRK, Panthappally SZ (1991) Stereospecific reactions of copper(II) complexes of serine and threonine with formaldehyde. Transit Met Chem 16:606–609CrossRefGoogle Scholar
  3. Bard AJ, Faulkner LR (2001) Electrochemical methods—fundamentals and applications, chap. 6: potential sweep methods, 6.2 Nernstian (reversible) systems, 2nd edn. Wiley, New York, p 231Google Scholar
  4. Barry PH, Lewis TM, Moorhouse AJ (2013) An optimized 3 M KCl salt-bridge technique used to measure and validate theoretical liquid junction potentials values in patch-clamping and electrophysiology. Eur Biophys J 42(8):631–646CrossRefGoogle Scholar
  5. Borgmann U, Ralph KM (1983) Complexation and toxicity of copper and the free metal bioassay technique. Water Res 17(11):1697–1703CrossRefGoogle Scholar
  6. Borsook H, Thimann KV (1932) The cupric complexes of glycine and of alanine. J Biol Chem 98(2):671–705Google Scholar
  7. Burke LD, Nugent T (1997) The electrochemistry of gold: I the redox behaviour of the metal in aqueous media. Gold Bull 30(2):43–53CrossRefGoogle Scholar
  8. Conato C, Contino A, Maccarrone G, Magrì A, Remelli M, Tabbì G (2000) Copper(II) complexes with l-lysine and ornithine: is the side-chain involved in the coordination? A thermodynamic and spectroscopic study. Thermochim Acta 362:13–23CrossRefGoogle Scholar
  9. de Mele MFL, Salvarezza RC, Vasquez Moll VD, Videla HA, Arvia AJ (1986) Kinetics and mechanism of silver chloride electroformation during the localized electrodissolution of silver in solutions containing sodium chloride. J Electrochem Soc 133(4):746–752CrossRefGoogle Scholar
  10. DeLacey EHB, White LR (1981) Dielectric Response and Conductivity of Dilute Suspensions of Colloidal Particles. J Chem Soc Faraday Trans 2(77):2007–2039CrossRefGoogle Scholar
  11. Doğan A, Köseoğlu F, Kiliç E (2001) The stability constants of copper(II) complexes with some α-AMINO ACIDS in dioxan–water mixtures. Anal Biochem 295:237–239CrossRefGoogle Scholar
  12. Gale RJ, Winkler CA (1977) Thermal rearrangement of the copper(II)—L-cystine complex. Inorg Chim Acta 21:151–156CrossRefGoogle Scholar
  13. Garnier A, Tosi L (1975) Cu(II)–poly(l-arginine) complexes. Potentiometric and spectral characterization of amine and peptide nitrogen ligands. Biopolymers 14(11):2247–2262CrossRefGoogle Scholar
  14. Gaur JN, Schmid GM (1970) Electrochemical behavior of gold in acidic chloride solutions. J Electroanal Chem 24(2–3):279–286Google Scholar
  15. Habbache N, Alane N, Djerad S, Tifouti L (2009) Leaching of copper oxide with different acid solutions. Chem Eng J 152:503–508. doi: 10.1016/j.cej.2009.05.020 CrossRefGoogle Scholar
  16. Käkinen A, Bondarenko O, Ivask A, Kahru A (2011) The effect of composition of different ecotoxicological tests media on free and bioavailable copper from CuSO4 and CuO nanoparticles: comparative evidence from a Cu-selective electrode and a Cu-biosensor. Sensors 11(11):10502–10521. doi: 10.3390/s111110502 CrossRefGoogle Scholar
  17. Karlsson HL, Cronholm P, Hedberg Y, Tornberg M, De Battice L, Svedhem S, Wallinder IO (2013) Cell membrane damage and protein interaction induced by copper containing nanoparticles—importance of the metal release process. Toxicology 313:59–69CrossRefGoogle Scholar
  18. Kizec R, Trnkova L, Ševčiková S, Šmarda J, František J (2002) Silver electrode as a sensor for the determination of zinc in cell cultivation Medium. Anal Biochem 301:8–13CrossRefGoogle Scholar
  19. Koch M, Kiefer S, Cavelius C, Kraegeloh A (2012) Use of a silver ion selective electrode to assess mechanisms responsible for biological effects of silver nanoparticles. J Nanopart Res 14:646–1051. doi: 10.1007/s1-011-0646-y CrossRefGoogle Scholar
  20. Koper OB, Lagadic I, Volodin A, Klabunde KJ (1997) Alkaline-earth oxide nanoparticles obtained by aerogel methods. Characterization and rational for unexpectedly high surface chemical reactivities. Chem Mater 9:2468–2480CrossRefGoogle Scholar
  21. Liu A-C, Chen D, Lin C-C, Chou H-H, Chen C (1999) Application of cysteine monolayers for electrochemical determination of sub-ppb copper(II). Anal Chem 71:1549–1552CrossRefGoogle Scholar
  22. Liu G, Yu S, Liu S (2013) Enhanced electrocatalytic reduction of oxygen by repetitive square wave potential signal treated gold electrodes. Indian J Chem 52A:357–361Google Scholar
  23. Malatesta F (2000) The impossibility of measuring individual ion activity coefficients using ion selective electrodes. J Solut Chem 29(9):771–779CrossRefGoogle Scholar
  24. Masuda H, Sugimori T, Odani A, Yamauchi O (1991) Structural evidence for the intramolecular charge-transfer interaction involving an indole ring in ternary copper(II) complexes with l-tryptophan and aromatic diamines. Inorg Chim Acta 180:73–79CrossRefGoogle Scholar
  25. Miao L, Wang C, Hou J, Wang P, Ao Y, Li Y, Lv B, Yang Y, You G, Xu Y (2015) Enhanced stability and dissolution of CuO nanoparticles by extracellular polymeric substancesin aqueous environment. J Nanopart Res 17:404. doi: 10.1007/s11051-015-3208-x CrossRefGoogle Scholar
  26. Midander K, Cronholm P, Karlsson HL, Elihn K, Möller L, Leygraf C, Wallinder IO (2009) Surface characteristics, copper release and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study. Small 5(3):389–399. doi: 10.1002/smll.2008012/20 CrossRefGoogle Scholar
  27. Millero FJ, Santana-Casiano JM, González-Dávila M (2010) The formation of Cu(II) Complexes with carbonate and bicarbonate ions in NaClO4 solutions. J Solution Chem 39:543–558. doi: 10.1007/s10953-010-9523-z CrossRefGoogle Scholar
  28. Neshkova MT, Kircova AA, Cattrall RW, Gregorio CG, Bond AM (1998) Flow injection discrimination of the chloride interference with Cu(II) electrode function of chalcogenide based solid-state copper ion-selective electrodes. Anal Chim Acta 362:221–234CrossRefGoogle Scholar
  29. Patra AK, Dhar S, Nethaji M, Chakravarty AR (2005) Metal-assisted red light-induced DNA cleavage by ternary Lmethionine copper(II) complexes of planar heterocyclic bases. Dalton Trans. doi: 10.1039/B416711B Google Scholar
  30. Patra AK, Roy S, Chakravarty AR (2009) Sinthesis, crystal structures, DNA binding and cleavage activity of l-glutamine copper(II) complexes of heterocyclic bases. Inorg Chim Acta 362:1591–1599CrossRefGoogle Scholar
  31. Ramakrishnan S, Rajendiran V, Palaniandavar M, Periasamy VS, Srinag BS, Krishnamurthy H, Akbarsha MA (2009) Induction of cell death by ternary copper(II) complexes of l-tyrosine and diimines: role of coligands on DNA binding and cleavage and anticancer acticity. Inorg Chem 48:1309–1322CrossRefGoogle Scholar
  32. Rand DAJ, Woods R (1972) A study of the dissolution of platinum, palladium rhodium and gold electrodes in 1 M sulphuric acid by cyclic voltammetry. J Electroanal Chem Surf Electrochem 35(1):209–218CrossRefGoogle Scholar
  33. Rao R, Patra AK, Chetana PR (2008) Synthesis, structure DNA binding and oxidative cleavage activity of ternary (Lleucine/isoleucine) copper(II) complexes of heterocyclic bases. Polyhedron 27(5):1343–1352CrossRefGoogle Scholar
  34. Schosseler PM, Wehrli B, Schweiger A (1997) Complexation of copper(II) with carbonate ligands in aqueous solution: a CW and pulsed EPR study. Inorg Chem 36:4490–4499CrossRefGoogle Scholar
  35. Sigel H, McCormick DB (1971) The structure of the copper(II)-l-histidine 1:2 complex in solution. J Am Chem Soc 93(8):2041–2044. doi: 10.1021/ja00737a032 CrossRefGoogle Scholar
  36. Tani Y, Soma M, Harsànyi EG, Umezawa Y (1999) Effect of dissolved oxygen on the response of Cu(II) ion-selective electrodes in metal buffer solutions. Anal Chim Acta 395:53–63CrossRefGoogle Scholar
  37. Valodkar VB, Tembe GL, Ravindranathan M, Ram RN, Rama HS (2004) Catalytic oxidation by polymer-supported copper(II)-l-valine complexes. J Mol Catal A: Chem 208:21–32CrossRefGoogle Scholar
  38. Viñes F, Gomes GRB, Illas F et al (2014) Understanding the reactivity of metallic nanoparticles: beyond the extended surface model for catalysis. Chem Soc Rev 43:4922CrossRefGoogle Scholar
  39. Wahl A, Dawson K, Sassiat N, Quinn AJ, O’Riordan A (2011) Nanomolar trace metal analysis of copper at gold microband arrays. J Phys 307:012061. doi: 10.1088/1742-6596/307/1/012061 Google Scholar
  40. Weeks CM, Cooper A, Norton DA (1969) The crystal structure of the copper(II) complex of L-isoleucine. Acta Cryst B25:443–450CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.ISTEC-CNRFaenzaItaly

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