Counting and differentiating aquatic biotic nanoparticles by full-field interferometry: from laboratory tests to Tara Oceans sample analysis

TL;DR

This paper introduces a novel interferometric detection method combined with Brownian motion analysis to detect, quantify, and differentiate aquatic biotic nanoparticles, validated with calibration and applied to ocean samples.

Contribution

A new full-field interferometry technique coupled with Brownian motion analysis for biotic nanoparticle detection and differentiation in seawater samples.

Findings

Detected viruses as small as 30 nm in diameter.

Revealed anisotropic Brownian motion trajectories for myoviruses.

Successfully applied to Tara Oceans samples for nanoparticle analysis.

Abstract

There is a huge abundance of viruses and membrane vesicles in seawater. We describe a new full-field, incoherently illuminated, shot-noise limited, common-path interferometric detection method that we couple with the analysis of Brownian motion to detect, quantify, and differentiate biotic nanoparticles. We validated the method with calibrated nanoparticles and homogeneous DNA or RNA.viruses. The smallest virus size that we characterized with a suitable signal-to-noise ratio was around 30 nm in diameter. Analysis of Brownian motions revealed anisotropic trajectories for myoviruses.We further applied the method for vesicles detection and for analysis of coastal and oligotrophic samples from Tara Oceans circumnavigation.