Graphene Oxide as a Quencher for Fluorescent Assay of Amino Acids, Peptides, and Proteins

Abstract

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.

Interactions between Carbon Nanomaterials and Biomolecules

“…To understand the roles of GO in interacting with biomolecules, Li et al 52 studied the effect of GO as a quencher on the fluorescent assay of amino acids, peptides, and proteins. The work started with the fluorescence quenching of L-Tyrosin Tyr and L-tryptophan Trp by GO.…”

Immunosensing procedures for carcinoembryonic antigen using graphene and nanocomposites

“…GO also quenches tryptophan or tyrosine containing peptides and proteins and electrostatic interaction plays an important role during quenching. Static quenching is the main mechanism, combined with Förster resonance energy transfer or dynamic quenching (Li et al, 2012). This is the rationale behind the use of GO together with a fluorescence dye in various IA formats.…”

Bovine α-lactalbumin functionalized graphene oxide nano-sheet exhibits enhanced biocompatibility: A rational strategy for graphene-based targeted cancer therapy

“…S2D, no peak shift of the spectra was observed, indicating BLA fluorescence quenching by GOns. In fact, it has already been reported that GO is a universal quencher, and it interacts with proteins through static as well as dynamic quenching [46].…”