Biphasic Microdroplet-Microdroplet Extraction for Ultra-Trace Enriching Analysis

Enriching trace targets from trace samples is essential for analytical chemistry. Here, a mini-pillar platform for biphasic (aqueous and organic) microdroplet-microdroplet extraction for enrichment analysis is demonstrated. Such mini-pillars with biphasic hydrophobicity can anchor the biphasic microdroplets (organic or aqueous) regardless of rotation and inversion. Methylene blue (MB) and Nile red (NR) are extracted and analyzed by single-phase extraction, double-phase extraction, and enrichment analysis. The results display the well linear relationships of all extraction processes with the high extraction efficiency of more than 80% in the single/double phase and up to 500% in the enrichment phase. This work remedies the deficiencies of traditional liquid phase extraction technology, such as extensive sample consumption, low sensitivity, complex equipment, and cumbersome operation. Furthermore, a portable, easy-manipulation, low-waste, high-throughput, and controllable liquid biphasic platform is proposed for high sensitivity, enrichment, and enhanced biphasic extraction analysis.

Automated summary

This study demonstrates a biphasic microdroplet-microdroplet extraction method using a mini-pillar platform for enrichment analysis. The method shows high efficiency and good linear relationships, and addresses the deficiencies of traditional liquid phase extraction technology.