Interfacial Partitioning Enhances Microextractionby Multicomponent Nanodroplets

TL;DR

This study demonstrates that chemical reactions within surface nanodroplets can significantly enhance analyte partitioning, improving extraction efficiency and sensitivity in microextraction processes.

Contribution

It introduces a novel approach where interfacial reactions in nanodroplets shift analyte partitioning, enabling more effective extraction from dilute solutions.

Findings

Partition coefficient decreased by 3 to 11 times due to reactions.

Enhanced analyte transfer across droplet surface observed.

Interfacial behavior improves extraction and detection sensitivity.

Abstract

The sensitive and reliable in-droplet chemical analysis benefits from the enhanced partition of an analyte into the droplets. This work, we will show that chemical reactions in surface nanodroplets can shift the partition of analytes from a highly diluted solution to the droplets. Seven types of organic acids with partition coefficients (LgP) ranging from -0.7 to 1.87 are used as model analytes dissolved in an oil solution that are extracted from the flow into aqueous nanodroplets immobilized on a substrate. The timescale of integrated extraction and reaction in droplets was represented by the decoloration time of the droplets. Our results show that the effective distribution coefficient of the analyte can be decreased by 3 to 11 times of the distribution coefficient of the analyte in the bulk liquids. The principle behind the significantly shifted partition is proposed to be enhanced the transfer of the analyte across the droplet surface. The chemical reaction in the droplets enhances the partition of the analyte from a highly diluted solution. Our results show that the interfacial behavior of the analyte may be advantageous as it may improve extraction and partition. Such enhanced extraction may be leveraged for sensitive chemical detection using reactive droplets.