Automated Paper-Based Femtogram Sensing Device for Competitive Enzyme-Linked Immunosorbent Assay of Aflatoxin B₁...

Area of Science:

• Analytical Chemistry
• Biosensor Technology
• Microfluidics

Background:

• Microfluidic paper-based analytical devices (μPADs) offer potential for portable bioanalytical applications.
• Automating assays like competitive enzyme-linked immunosorbent assay (ELISA) is crucial for sensitive detection.
• Small-sized molecule detection requires methods with high sensitivity and minimal sample volume.

Purpose of the Study:

• To develop an automated μPAD for competitive ELISA of small-sized targets at the femtogram level.
• To integrate a sucrose valve for automated sequential reagent delivery.
• To minimize sample volume and prevent target molecule loss for enhanced sensitivity.

Main Methods:

• Fabrication of a μPAD with pre-functionalized antibody-conjugated enzyme zones.
• Integration of a sucrose valve for automated reagent delivery.
• Utilizing a specific sample dropping location to minimize adsorption and sample volume (0.6 μL).

Main Results:

• Successful automation of competitive ELISA for aflatoxin B1 (AFB1) detection.
• Achieved a detection limit of 60 femtograms (0.1 ng/mL) for AFB1.
• Demonstrated high sensitivity, minimal sample volume, and equipment-free operation.

Conclusions:

• The developed μPAD enables sensitive, automated competitive ELISA with low sample volumes.
• The device offers on-site, equipment-free, and user-friendly measurements for small-sized molecules.
• Potential applications include food safety, environmental monitoring, and clinical diagnostics.