In situ quantitative measurement of concentration profiles in a microreactor with submicron resolution using...

Area of Science:

• Chemical Engineering
• Spectroscopy
• Microfluidics

Background:

• Understanding reaction dynamics in microfluidic devices is crucial for process optimization.
• Real-time, in situ monitoring of chemical species is often limited by resolution and sensitivity.
• Label-free techniques are desirable to avoid interference with reaction pathways.

Purpose of the Study:

• To develop and demonstrate a label-free method for in situ quantitative imaging of concentration profiles within microfluidic reactors.
• To achieve submicron spatial resolution and millisecond temporal resolution for monitoring chemical reactions.
• To validate the technique using a well-understood elementary acid-base reaction.

Main Methods:

• Utilized Coherent Anti-Stokes Raman scattering (CARS) microscopy in a spectrally resolved manner.
• Employed quantitative vibrational spectroscopy for label-free analysis.
• Performed in situ measurements within a microfluidic reactor setup.

Main Results:

• Achieved quantitative imaging of reactant and product concentration profiles with submicron spatial resolution.
• Demonstrated millisecond time scale measurements at specific positions.
• Obtained mM sensitivity for detected chemical species.
• Successfully applied the method to an elementary acid-base reaction.

Conclusions:

• Coherent Anti-Stokes Raman scattering microscopy enables label-free, in situ quantitative monitoring of microfluidic reactions.
• The developed technique offers high spatial and temporal resolution for chemical process analysis.
• This approach provides valuable insights into reaction kinetics and mechanisms at the microscale.