Microfluidic Gas Sensors: Detection Principle and Applications.

Area of Science:

• Microfluidics
• Sensor Technology
• Analytical Chemistry

Background:

• Emerging point-of-use (POU)/point-of-care (POC) detection technologies require miniaturized sensors for real-time monitoring of gases and airborne pathogens.
• Developing low-cost, highly selective, and sensitive miniaturized gas sensors with fast response times remains a significant challenge.
• Microfluidics offers a promising platform to overcome these limitations, though microfluidic-based gas sensors are still an emerging field.

Purpose of the Study:

• To review the evolution of microfluidic gas sensors, from basic electronic to advanced optical techniques.
• To focus on diverse detection methodologies within microfluidic devices for gases and airborne pathogens.
• To discuss non-continuous microfluidic approaches, including bubble/droplet-based systems.

Main Methods:

• Detailed documentation of microfluidic sensor evolution, encompassing electronic and optical techniques like surface-enhanced Raman spectroscopy.
• Focus on various detection methodologies employed in microfluidic devices for gas and airborne pathogen analysis.
• Inclusion of non-continuous microfluidic technologies, such as bubble/droplet-based systems.

Main Results:

• Tabulation of microfluidic sensors based on selectivity, sensitivity, response time, advantages/disadvantages, and fabrication costs.
• Categorization of sensors by target moiety, including air pollutants (CO, NOx) and airborne pathogens (E. coli, SARS-CoV-2).
• Critical examination of potential application scenarios for diverse microfluidic devices.

Conclusions:

• Microfluidic technology is a key enabler for advanced POU/POC detection of environmental and health threats.
• The review provides a comprehensive overview of current microfluidic gas and airborne pathogen sensor technologies.
• Further development in microfluidic sensors is crucial for combating pollution, emerging contaminants, and pandemics effectively.