Microfluidic Diatomite Analytical Devices for Illicit Drug Sensing with ppb-Level Sensitivity

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Microfluidics and porous media are crucial for developing advanced analytical devices.
• Microfluidic paper-based analytical devices are increasingly used for point-of-care (POC) diagnostics.
• There is a need for sensitive and specific platforms for illicit drug detection.

Purpose of the Study:

• To introduce microfluidic diatomite analytical devices (μDADs) as an innovative lab-on-a-chip platform.
• To demonstrate the capability of μDADs for detecting illicit drugs in complex biological samples.
• To highlight the potential of μDADs for sensitive chemical and biomedical sensing.

Main Methods:

• Fabrication of μDADs using spin-coating and tape-stripping of diatomaceous earth on glass slides.
• Integration of on-chip chromatography for sample separation within microfluidic channels.
• Utilizing surface-enhanced Raman scattering (SERS) for high-specificity chemical detection.

Main Results:

• Achieved simultaneous on-chip chromatography and SERS detection.
• Demonstrated high sensitivity for pyrene detection at 1 part-per-billion (ppb) and cocaine at 10 ppb in human plasma.
• Leveraged the photonic crystal effect of diatom frustules for enhanced sensitivity.

Conclusions:

• μDADs represent a pioneering microfluidic device for chemical and biomedical sensing.
• The platform shows significant advantages for point-of-care drug screening.
• The unique properties of diatomite enable ultra-sensitive detection in complex matrices.