Microfluidic Solid-State pH Sensor for Dynamic Monitoring of Extracellular pH in Live Cell Cultures.

Area of Science:

• Biomedical Engineering
• Cellular Metabolism
• Sensor Technology

Background:

• Real-time monitoring of extracellular acidification is vital for understanding cellular metabolism dynamics.
• Existing methods may lack the sensitivity or real-time capabilities required for comprehensive metabolic analysis.

Purpose of the Study:

• To present a microfluidic device featuring a solid-state potentiometric pH sensor for accurate extracellular acidification rate (ECAR) monitoring in live cell cultures.
• To demonstrate the device's capability for noninvasive, continuous pH monitoring with minimal sample volume.

Main Methods:

• Development of a microfluidic device integrated with a two-electrode potentiometric pH sensor (Ag/AgCl and RuO2).
• Utilized a Polydimethylsiloxane (PDMS)-based microfluidic culture chamber for live cell culture.
• Performed ECAR measurements on HeLa cells, including responses to metabolic modulators like glucose and oligomycin.

Main Results:

• The potentiometric pH sensor exhibited high sensitivity (-93 mV/pH), Nernst response, repeatability, and reproducibility.
• The device successfully detected basal and stress-induced ECAR in HeLa cells, showing rapid responses to metabolic challenges.
• The system demonstrated high performance with as few as 300-500 cells, suitable for limited biological samples.

Conclusions:

• The developed microfluidic platform provides a powerful tool for real-time metabolic analysis.
• This technology has broad applications in cancer research, drug screening, and bioenergetic diagnostics.
• The compact and scalable design facilitates advanced cellular metabolic profiling.