Real-time simultaneous visualization of lactate and proton dynamics using a 6-μm-pitch CMOS multichemical image...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Analytical Chemistry

Background:

• Understanding extracellular chemical signaling is vital for brain function and pathology.
• Current methods for analyzing these molecules often lack spatial or temporal resolution.
• Label-free detection is desirable for preserving biological system integrity.

Purpose of the Study:

• To develop a CMOS-based multichemical image sensor for simultaneous, label-free detection and imaging of lactate and proton (H+) dynamics.
• To achieve subcellular resolution in real-time imaging of these key extracellular molecules.
• To provide a novel bioimaging tool for studying extracellular microenvironments.

Main Methods:

• Fabrication of a 6-μm-pitch CMOS potentiometric sensor array with gold electrode patterns.
• Utilized semiconductor lithography for sensor construction.
• Lactate detection via potentiometry using lactate oxidase and horseradish peroxidase enzyme-based redox reactions.

Main Results:

• Achieved a pH sensitivity of 65 mV and a lactate detection limit of 1 μM with good selectivity.
• Successfully obtained concurrent diffusion images of lactate and proton (H+) distributions.
• Demonstrated simultaneous real-time imaging of both analytes with subcellular resolution.

Conclusions:

• The developed multichemical image sensor enables simultaneous, label-free visualization of lactate and proton (H+) dynamics.
• The sensor provides high sensitivity, selectivity, and subcellular resolution for bioimaging applications.
• This novel device holds potential for effective application in extracellular microenvironments of tissue and cell samples.