Graphene oxide as a quencher for fluorescent assay of amino acids, peptides, and proteins

Shanghao Li, Ashish N. Aphale, Isaac G. MacWan, Prabir K. Patra, Walter G. Gonzalez, Jaroslava Miksovska, Roger M. Leblanc

Research output: Contribution to journalArticlepeer-review

138 Scopus citations


Understanding the interaction between graphene oxide (GO) and the biomolecules is fundamentally essential, especially for disease-and drug-related peptides and proteins. In this study, GO was found to strongly interact with amino acids (tryptophan and tyrosine), peptides (Alzheimer's disease related amyloid beta 1-40 and type 2 diabetes related human islet amyloid polypeptide), and proteins (drug-related bovine and human serum albumin) by fluorescence quenching, indicating GO was a universal quencher for tryptophan or tyrosine related peptides and proteins. The quenching mechanism between GO and tryptophan (Trp) or tyrosine (Tyr) was determined as mainly static quenching, combined with dynamic quenching (Förster resonance energy transfer). Different quenching efficiency between GO and Trp or Tyr at different pHs indicated the importance of electrostatic interaction during quenching. Hydrophobic interaction also participated in quenching, which was proved by the presence of nonionic amphiphilic copolymer Pluronic F127 (PF127) in GO dispersion. The strong hydrophobic interaction between GO and PF127 efficiently blocked the hydrophobic interaction between GO and Trp or Tyr, lowering the quenching efficiency.

Original languageEnglish (US)
Pages (from-to)7069-7075
Number of pages7
JournalACS Applied Materials and Interfaces
Issue number12
StatePublished - Dec 26 2012


  • amino acid
  • graphene oxide
  • interaction
  • peptide
  • protein
  • quenching

ASJC Scopus subject areas

  • Materials Science(all)
  • Medicine(all)


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