Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles


The surface chemistry of gold nanoparticles (AuNPs) plays a critical role in the self-assembly of thiolated molecules and in retaining the biological function of the conjugated biomolecules. According to the well-established gold–thiol interaction the undefined ionic species on citrate-reduced gold nanoparticle surface can be replaced with a self-assembled monolayer of certain thiolate derivatives and other biomolecules. Understanding the effect of such derivatives in the functionalization of several types of biomolecules, such as PEGs, peptides or nucleic acids, has become a significant challenge. Here, an approach to attach specific biomolecules to the AuNPs (~14 nm) surface is presented together with a study of their effect in the functionalization with other specific derivatives. The effect of biofunctional spacers such as thiolated poly(ethylene glycol) (PEG) chains and a positive peptide, TAT, in dsRNA loading on AuNPs is reported. Based on the obtained data, we hypothesize that loading of oligonucleotides onto the AuNP surface may be controlled by ionic and weak interactions positioning the entry of the oligo through the PEG layer. We demonstrate that there is a synergistic effect of the TAT peptide and PEG chains with specific functional groups on the enhancement of dsRNA loading onto AuNPs.

This is a preview of subscription content, log in to check access.

Scheme 1
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7


  1. Baptista PV (2009) Cancer nanotechnology—prospects for cancer diagnostics and therapy. Curr Cancer Therapy Rev 5:80–88

  2. Daniel MC, Astruc D (2004) Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology. Chem Rev 104:293–346

  3. El-Sayed MA (2001) Some interesting properties of metals confined in time and nanometer space of different shapes. Acc Chem Res 34:257–264

  4. Grabarek Z, Gergely J (1990) Zero-length crosslinking procedure with the use of active esters. Anal Biochem 185:131–135

  5. Han G, Ghosh P, Rotello VM (2007) Multi-functional gold nanoparticles for drug delivery. Adv Exp Med Biol 620:48–56

  6. Kim KY (2007) Nanotechnology platforms and physiological challenges for cancer therapeutics. Nanomedicine 3:103–110

  7. Kommareddy S, Tiwari S, Amiji MM (2005) Long-circulating nanovectors for tumor-specific gene delivery. Technol Cancer Res Treat 4:615–626

  8. Lee PC, Meisel D (1982) Adsorption and surface-enhanced Raman of dyes on silver and gold sols. J Phys Chem 86:3391–3395

  9. Link S, El-Sayed MA (2003) Optical properties and ultrafast dynamics of metallic nanocrystals. Annu Rev Phys Chem 54:331–366

  10. Liu Y, Shipton MK, Ryan J et al (2007) Synthesis, stability, and cellular internalization of gold nanoparticles containing mixed peptide-poly(ethylene glycol) monolayers. Anal Chem 79:2221–2229

  11. Sanvicens N, Marco MP (2008) Multifunctional nanoparticles—properties and prospects for their use in human medicine. Trends Biotechnol 26:425–433

  12. Sperling RA, Parak W (2010) Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles. Phil Trans A Math Phys Eng Sci 368:1333–1383

  13. Staros JV, Wright RW, Swingle DM (1986) Enhancement by N-hydroxysulfosuccinimide of water-soluble carbodiimide-mediated coupling reactions. Anal Biochem 156:220–222

  14. Verma A, Stellacci F (2010) Effect of surface properties on nanoparticle-cell interactions. Small 6:12–21

  15. Yu WW, Chang E, Falkner JC et al (2007) Forming biocompatible and nonaggregated nanocrystals in water using amphiphilic polymers. J Am Chem Soc 129:2871–2879

Download references


This study has been funded by CTQ2008-03739/PPQ, NanoSciERA Grant-NANOTRUCK, and ERC-Starting Grant 239931-NANOPUZZLE. J. Conde thanks FCT/MCTES (SFRH/BD/62957/2009). P.V. Baptista thanks CIGMH-FCT/MCTES and JM de la Fuente thanks ARAID for financial support. Authors also thank I. Echaniz and S. Rivera for technical support.

Author information

Correspondence to Jesús M. de la Fuente.

Electronic supplementary material

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sanz, V., Conde, J., Hernández, Y. et al. Effect of PEG biofunctional spacers and TAT peptide on dsRNA loading on gold nanoparticles. J Nanopart Res 14, 917 (2012). https://doi.org/10.1007/s11051-012-0917-2

Download citation


  • Gold nanoparticles
  • PEG biofunctional spacers
  • TAT peptide
  • dsRNA oligonucleotide
  • Surface science