Evolution of thiol-capped gold nanoclusters into larger gold nanoparticles under electron beam irradiation

Mukesh Kumar Kumawat; Mukeshchand Thakur; Jaya R Lakkakula; Deepika Divakaran; Rohit Srivastava

doi:10.1016/j.micron.2017.01.002

Evolution of thiol-capped gold nanoclusters into larger gold nanoparticles under electron beam irradiation

Micron. 2017 Apr:95:1-6. doi: 10.1016/j.micron.2017.01.002. Epub 2017 Jan 15.

Authors

Mukesh Kumar Kumawat¹, Mukeshchand Thakur¹, Jaya R Lakkakula¹, Deepika Divakaran¹, Rohit Srivastava²

Affiliations

¹ Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
² Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India. Electronic address: rsrivasta@iitb.ac.in.

PMID: 28119149
DOI: 10.1016/j.micron.2017.01.002

Abstract

We report in situ transformation of glutathione-capped red-fluorescent gold nanoclusters (AuNCs) into larger gold nanoparticles (AuNPs) embedded on a copper grid under high energy electron beam of Field Emission Gun Transmission Electron Microscope (FEG-TEM). Electron beam irradiation causes coalescing of individual finer AuNCs into bigger discrete AuNPs as a function of electron dose rate and time. The coalescence was closely studied over time and the mechanism is discussed. The study will help to understand the structural and morphological changes that occur in AuNCs inside FEG-TEM due to prolonged electron beam exposure.

Keywords: Coalescence; Electron beam irradiation; Gold nanoclusters; Gold nanoparticles; In situ.