Chemical imaging of microfluidic flows using ATR-FTIR spectroscopy

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Microfluidics

Background:

• Understanding chemical composition in microfluidic flows is vital for optimizing reactions.
• Current methods may require labels or dyes, limiting direct analysis.

Purpose of the Study:

• To develop and demonstrate a novel label-free detection methodology for microfluidic applications.
• To enable direct chemical composition analysis and imaging within microfluidic devices.

Main Methods:

• Implementation of Attenuated Total Reflection (ATR)-Fourier Transform Infra-Red (FTIR) spectroscopic imaging.
• Utilizing an infrared focal plane array detector with an inverted prism-shape ATR crystal.
• Integration with a poly(dimethylsiloxane)-based microfluidic mixing device.

Main Results:

• Direct measurement and imaging of liquid mixing based on viscosity differences.
• Imaging and analysis of H2O and D2O mixing with H/D isotope exchange.
• Demonstration of chemically specific imaging as a function of spatial position.

Conclusions:

• The developed ATR-FTIR spectroscopic imaging method provides a powerful tool for microfluidic analysis.
• This label-free approach facilitates direct study of chemical processes in microfluidics.
• The technique is applicable to a wide range of microfluidic applications, including reactions and separations.