A Portable 3D Microfluidic Origami Biosensor for Cortisol Detection in Human Sweat

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Cortisol analysis in sweat is crucial for monitoring stress-related disorders and human health status.
• Existing methods for cortisol detection can be invasive or lack real-time capabilities.
• There is a need for portable, rapid, and non-invasive biosensing solutions for point-of-care applications.

Purpose of the Study:

• To develop a portable 3D microfluidic origami biosensor for detecting cortisol levels in human sweat.
• To utilize molybdenum disulfide (MoS2) nanosheet-mediated fluorescence resonance energy transfer (FRET) for enhanced biosensing.
• To validate the biosensor's performance using smartphone-based fluorescence analysis.

Main Methods:

• Fabrication of a multilayer 3D origami microfluidic chip for sweat collection and detection.
• Functionalization of the chip with MoS2 nanosheets and fluorescently labeled aptamers.
• Optimization of critical parameters including paper substrates, MoS2 concentration, and incubation time.
• Smartphone-based fluorescence analysis for translatability and data acquisition.

Main Results:

• The developed biosensor achieved a limit of detection (LOD) of 6.76 ng/mL in artificial sweat.
• The assay demonstrated a rapid analysis time of 25 minutes with high selectivity.
• Correlation coefficient of 0.988 was observed when compared to ELISA in spiked artificial sweat.
• Satisfactory results were obtained for cortisol level determination in real human sweat samples.

Conclusions:

• The portable 3D microfluidic origami biosensor offers a rapid, low-cost, convenient, and non-invasive solution for point-of-care cortisol analysis.
• The biosensor effectively detects cortisol levels in human sweat, providing real-time health status information.
• This technology holds promise for improved monitoring of stress-related disorders and personalized healthcare.