In situ structural analysis with a SAXS laboratory beamline on a microfluidic chip

Area of Science:

• Materials Science
• Analytical Chemistry
• Biophysics

Background:

• Coupling microfluidic chips with X-ray equipment enables direct structural analysis within microfluidic devices.
• Traditionally, this technique requires intense, small X-ray beams available only at synchrotron facilities.
• Limitations include the accessibility and cost associated with synchrotron radiation sources.

Purpose of the Study:

• To demonstrate reliable structural analysis using X-ray scattering in microfluidic devices without synchrotron access.
• To evaluate the potential of an improved laboratory X-ray beamline and optimized microfluidic chip design.
• To establish a versatile setup for in situ and operando structural analysis in lab-on-a-chip devices.

Main Methods:

• Development of an optimized microfluidic device design.
• Implementation of an improved laboratory X-ray beamline.
• Small-angle X-ray scattering (SAXS) analysis of various dispersions within the microfluidic setup.

Main Results:

• Reliable structural information was obtained from gold and silica nanoparticles, bovine serum albumin (BSA), and latex nanospheres.
• The setup demonstrated its capability across a range of sample contrasts, from strong to weak.
• Proof of concept for a versatile, lab-based SAXS system for microfluidic sample analysis was established.

Conclusions:

• An accessible laboratory X-ray scattering setup can replace synchrotron sources for microfluidic structural analysis.
• The developed system facilitates in situ and operando studies, advancing lab-on-a-chip capabilities.
• This approach democratizes structural analysis for a wider range of scientific applications.