Enhancing the concentration capability of nonsupported electrically driven liquid-phase microextraction through programmable flow using an all-in-one 3d-printed optosensor: a proof of concept

Abstract

[eng] A versatile millifluidic 3D-printed inverted T-shaped unit (3D-TSU) was prototyped to ameliorate the concentration capability of non-supported micro-electromembrane extraction (µ-EME), exploiting optosensing detection for real-time monitoring of the enriched acceptor phase (AP). Continuous forward-flow and stop-and-go flow modes of the donor phase (DP) were implemented via an automatic programmable-flow system to both disrupt the electrical double layer generated at the DP/organic phase (OP) interface while replenishing the potentially depleted layers of analyte in DP. To further improve the enrichment factor (EF), the organic holding section of the OP/AP channel was bifurcated to increase the interfacial contact area between the DP and the OP. Exploiting the synergistic assets of continuous forward-flow of DP (1050 µL), a unique pentagon cross-sectional geometry of the OP/AP channel, bifurcation of the OP that renders an inverted Y-shape configuration, and in-situ optosensing of the AP, a </span><em style="color:black">ca</em><span style="color:black">. 24 EF was obtained for a 20 min of extraction using methylene blue (MB) as a model analyte. The 3D-printed Y-shaped unit (3D-YSU) was leveraged for the unsupervised µ-EME and the determination of MB in textile dyeing and urban wastewater samples, with relative recoveries ≥ 88%. This is the first work toward analyte preconcentration in µ-EME and in-situ optosensing of resulting extracts using 3D-printed millifluidic platforms.