Gas-mediated crosstalk in droplet flow - Characterisation and correction

Abstract

This paper describes inter-droplet crosstalk encountered whilst implementing a nitrate assay in a droplet flow regime. Whilst several reports in recent years have shown that dissolved solutes can transfer into the oil phase and migrate into neighbouring droplets under certain conditions, almost all have described surfactant-driven mechanisms such as transport via micelles. Here, crosstalk was driven by a very different mechanism: conversion of the analyte to a gaseous intermediate which subsequently moved unhindered between droplets. The crosstalk occurred predictably and could be experimentally quantified, which led to the development of a mathematical model to rationally post-correct measurements.