A spectIR-fluidic reactor for monitoring fast chemical reaction kinetics with on-chip attenuated total reflection Fourier transform infrared spectroscopy

Microfluidics has emerged as a powerful technology with diverse applications in microbiology, medicine, chemistry, and physics. While its potential for controlling and studying chemical reactions is well recognized, the extraction and utilization of the vast amounts of high-quality information generated within microfluidic devices remain challenging. This is mainly due to the limited tools available for in situ measurements of chemical reactions. In this study, we present a proof-of-concept spectIR-fluidic reactor design that combines microfluidics with Fourier transform infrared (FTIR) spectroscopy for in situ kinetic studies of fast reactions. By integrating a multi-ridge silicon attenuated total reflection (ATR) wafer into the microfluidic device, we enable multi-point measurements for precise reaction time monitoring. This work establishes a validated foundation for studying a wide range of chemical reactions using ATR-FTIR spectroscopy, which will enable simultaneous quantification of reagents, intermediates, and products. The spectIR-fluidic platform offers customizable designs, allowing for the investigation of reactions with various time scales, and has the potential to significantly advance reaction optimization and pathway exploration.