Efficient fluorescence quenching in electrochemically exfoliated graphene decorated with gold nanoparticles

TL;DR

This study presents a method to produce high-quality electrochemically exfoliated graphene decorated with gold nanoparticles, achieving efficient fluorescence quenching and a high quantum yield of 40.04%, with potential applications in sensing.

Contribution

The paper introduces a non-covalent functionalization technique for EEG with AuNPs that preserves electronic properties and enhances fluorescence efficiency.

Findings

High-quality EEG was successfully decorated with AuNPs.

The decorated EEG exhibited a fluorescence quantum yield of 40.04%.

The method maintains the electronic properties of EEG while enabling fluorescence applications.

Abstract

High surface area graphene sheets were obtained by electrochemical exfoliation of graphite in an acid media under constant potential conditions. Filtration and centrifugation processes played an important role in order to obtain stable dispersions in water. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging revealed highly exfoliated crystalline samples of ~5(\mum). Raman, FT-IR and XPS spectroscopy further confirmed the high quality of the exfoliated material. The electrochemically exfoliated graphene (EEG) was decorated with gold nanoparticles (AuNP) using sodium cholate (SC) as a buffer layer. This approach allowed for a non-covalent functionalization without altering the desirable electronic properties of the EEG. The AuNP-EEG samples were characterized with various techniques including absorbance and fluorescence spectroscopy. These samples displayed a fluorescence signal using an excitation wavelength of 290nm. The calculated quantum yield (?) for these samples was 40.04%, a high efficiency compared to previous studies using solution processable graphene.