Dynamic Imaging of Au-nanoparticles via Scanning Electron Microscopy in a Graphene Wet Cell

TL;DR

This paper introduces a graphene-based wet cell device enabling high-resolution SEM imaging of nanoparticles in liquid, allowing direct nanoscale visualization and composition analysis in liquid environments.

Contribution

A novel graphene wet cell device that allows high-resolution SEM and EDX imaging of nanoparticles directly in liquid environments, surpassing conventional silicon nitride devices.

Findings

Achieved < 5 nm resolution SEM imaging of nanoparticles in liquid.

Enabled EDX analysis of nanoparticle composition in liquid.

Demonstrated real-time imaging of nanoparticle motion in liquid.

Abstract

High resolution nanoscale imaging in liquid environments is crucial for studying molecular interactions in biological and chemical systems. In particular, electron microscopy is the gold-standard tool for nanoscale imaging, but its high-vacuum requirements make application to in-liquid samples extremely challenging. Here we present a new graphene based wet cell device where high resolution SEM (scanning electron microscope) and Energy Dispersive X-rays (EDX) analysis can be performed directly inside a liquid environment. Graphene is an ideal membrane material as its high transparancy, conductivity and mechanical strength can support the high vacuum and grounding requirements of a SEM while enabling maximal resolution and signal. In particular, we obtain high resolution (< 5 nm) SEM video images of nanoparticles undergoing brownian motion inside the graphene wet cell and EDX analysis of nanoparticle composition in the liquid enviornment. Our obtained resolution surpasses current conventional silicon nitride devices imaged in both SEM and TEM under much higher electron doses.