Microfluidic origami: A new device format for in-line reaction monitoring by nanoelectrospray ionization mass spectrometry

Article abstract of DOI:10.1039/c3lc41431k

Microfluidics is an attractive platform for chemical synthesis because it offers fast reaction times, reduced reagent usage, and the ability to integrate multiple functions on a single device. Digital Microfluidics (DMF) is particularly well-suited for microscale chemical synthesis, as it permits discretized sample handling, allowing for total process control. However, a limitation of DMF-based synthesis is analysis, which is often performed offline. To this end, we have developed "microfluidic origami", a new device format that integrates DMF with in-line analysis by mass spectrometry (MS). This format comprises a DMF platform and a folded nanoelectrospray ionization (nanoESI) emitter formed on a single flexible polyimide film substrate. Additionally, the device contains a two-plate-to-one-plate DMF interface, which allows for straightforward coupling of micro-reaction operations and product delivery to the emitter for analysis. The integrated platform was used to perform the Morita-Baylis-Hillman (MBH) reaction using DMF followed by inline MS analysis for monitoring the reaction progress in real-time. We propose that this platform has potential as a new tool for real-time monitoring of reaction rates and reaction pathways and could be a useful addition to the synthetic organic chemistry laboratory.