Revolutionizing Environmental Monitoring: The Rise of Microfluidic Devices

Advancements in microfluidic devices over the past five years have led to significant advancements in environmental monitoring, according to a recent review article published in Lab Chip (1).

The review article, written by Charles S. Henry from Colorado State University and his colleagues, details how microfluidic devices, because of their portability, cost-effectiveness, ease of use, and rapid response capabilities, have resulted in improved environmental monitoring.

sustainability researcher with a backdrop of green energy sources and data analytics screens | Image Credit: © 1st footage - stock.adobe.com

Microfluidic devices have become indispensable tools in detecting a broad spectrum of environmental contaminants across various matrices, including air, water, and soil (1,2). They also find significant applications in agricultural monitoring (2). Henry and his team focus their review article on prominent contaminants such as heavy metals, pesticides, nutrients, microorganisms, and per- and polyfluoroalkyl substances (PFAS) (1). They highlight the numerous detection methods used for this purpose, including electrochemical, colorimetric, and fluorescent techniques, offering a critical assessment of the current state of microfluidic devices for environmental monitoring.

Starting with electrochemical detection methods, the researchers mentioned that their specificity and sensitivity make them excellent for detecting pesticides and heavy metals (1). On the other end of the spectrum, colorimetric methods are most often used in field testing. This is because of their simplicity and cost-effectiveness (1). Fluorescent methods provide high sensitivity and are particularly effective in detecting microorganisms and other biological contaminants (1). Each method's strengths and limitations are thoroughly discussed, offering insights into their applications and potential areas for improvement.

The researchers also highlighted how commercialization is affecting the widespread use of microfluidic devices. Despite their benefit in this space, microfluidic devices have encountered several challenges, such as the introduction of viable alternatives entering the market. This includes thermal transfer printing, laser cutting, screen printing, photolithography, and laminate capillary-driven microfluidics (1).

Lamination-based microfluidics, which employ layered paper, film, acrylics, and glass slides, offer strong channels with enhanced performance. These advancements eliminate the uneven flow and resistance in porous paper microchannels, suggesting a promising future for improved microfluidic systems (1). Furthermore, three-dimensional (3D) printing has emerged as a game-changer because of its intrinsic versatility, allowing for the design of microfluidic devices with various geometries and features tailored to specific applications (1). The precision of 3D printing, capable of producing devices with submicron channels, coupled with the decreasing costs of printers, makes it an attractive option for low-cost prototyping and mass manufacturing (1).

Currently, microfluidic devices are being integrated with sample preparation and detection systems in order to expand their utility and value. This integration could significantly speed up testing, reduce processing time, and enhance safeguards against contamination (1). The review emphasized the importance of broadening the approach to consider various analytes in a single run, particularly in active environmental monitoring. Detecting multiple analytes simultaneously could yield substantial economic and resource benefits, enhancing the efficiency of environmental monitoring efforts (1).

As the field continues to advance, the integration of advanced manufacturing methods and innovative detection techniques holds promise for the future of environmental monitoring. The ongoing research and development in this area, which was highlighted in this review article, will have far-reaching implications in how we detect and respond to environmental contaminants.

References

(1) Aryal, P.; Hefner, C.; Martinez, B.; Henry, C. S. Microfluidics in Environmental Analysis: Advancements, Challenges, and Future Prospects for Rapid and Efficient Monitoring. Lab Chip 2024, 24, 1175–1206. DOI: 10.1039/D3LC00871A

(2) Kamat, V.; Burton, L.; Venkadesh, V.; et al. Enabling Smart Agriculture through Sensor-Integrated Microfluidic Chip to Monitor Nutrient Uptake in Plants. ECS Sensors Plus 2023, 2 (4), 043201. DOI: 10.1149/2754-2726/ad024e