Imaging Gold Nanoparticles in Living Cells Environments using Heterodyne Digital Holographic Microscopy

TL;DR

This paper presents a heterodyne digital holographic microscopy technique capable of accurately imaging and localizing 40 nm gold nanoparticles within living cell environments, achieving nanometer-scale precision.

Contribution

It introduces a novel holographic microscopy method for 3D localization of gold nanoparticles in living cells with high spatial accuracy.

Findings

Gold nanoparticles are localized with 5 nm lateral precision.

The technique achieves 100 nm axial localization accuracy.

Gold nanoparticles provide higher scattering contrast than cellular structures.

Abstract

This paper describes an imaging microscopic technique based on heterodyne digital holography where subwavelength-sized gold colloids can be imaged in cell environment. Surface cellular receptors of 3T3 mouse fibroblasts are labeled with 40 nm gold nanoparticles, and the biological specimen is imaged in a total internal reflection configuration with holographic microscopy. Due to a higher scattering efficiency of the gold nanoparticles versus that of cellular structures, accurate localization of a gold marker is obtained within a 3D mapping of the entire sample's scattered field, with a lateral precision of 5 nm and 100 nm in the x,y and in the z directions respectively, demonstrating the ability of holographic microscopy to locate nanoparticles in living cells environments.