Covalent anchoring of atomically precise glutathione-protected gold nanoclusters on graphene oxide nanosheets

Franck Bertorelle,Srestha Basu,Pierre-François Brevet,Isabelle Russier-Antoine,Hussein Fakhouri,Pierre Mignon,Nandakumar Kalarikkal,Martina Perić Bakulić,Sabu Thomas,Rodolphe Antoine

doi:10.1088/2632-959x/abbe31

Abstract

This paper describes the development of a novel method of producing nanocomposites consisting of gold nanoclusters anchored on graphene oxide nanosheets in a cost-effective and reproducible manner. The novelty of the technique hinges on the covalent functionalization of atomically precise subnanometer gold clusters protected by glutathione (Au15SG13 and Au25SG18) on to graphene oxide (GO) nanosheets according to the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride crosslinking method, using the existing carboxylic groups present both at the surfaces of the nanoclusters and the GO nanosheets. The atomic precision of glutathione-protected gold nanoclusters was evidenced by electrospray ionization mass spectrometry. The formed hybrid nanocomposites were characterized by TEM measurements and exhibit nonlinear optical properties characteristic of GO, in particular a strong second harmonic scattering response as well as a multi-photon excited fluorescence spectrum characterized by a broad band in the visible range between 350 and 700 nm. Atomically precise nanoclusters covalently linked to GO nanosheets are therefore promising for new applications in the areas of optoelectronics and photovoltaics.

Highlights

The large surface areas of graphenic materials provide ideal platforms to capture active molecules and clusters [1]
In our previous work [26], quantitative x-ray photoelectron analysis was conducted on graphene oxide (GO) nanosheets, leading to ∼6% of carboxylic groups with a total oxygen content of 25%
Through the presence of –COOH groups on the surface of both glutathione protected gold nanoclusters and GO nanosheets, we have explored a novel synthesis method to anchor atomically precise Au25 and Au15 NCs onto graphene via the use of EDC chemistry to activate and promote covalent bonding reaction with ethylenediamine

Summary

October 2020

Sciences and Technology (ICAST), University of Split, Poljička cesta 35, Split 21000, Croatia 3 International and Inter University Centre for Nanoscience and Nanotechnology Mahatma Gandhi University, Kottayam 686560, Kerala, India.

Introduction

Experimental

Results and discussion

Conclusions