Microchip separations of protein biotoxins using an integrated hand-held device

Area of Science:

• Analytical Chemistry
• Biotechnology
• Forensic Science

Background:

• Accurate and rapid detection of protein biotoxins is crucial for public health and security.
• Existing methods often lack portability or require complex sample preparation.
• The need for orthogonal analytical techniques to improve biotoxin identification confidence.

Purpose of the Study:

• To develop and demonstrate a portable, hand-held instrument for simultaneous microchip separations.
• To utilize two orthogonal electrophoresis methods for enhanced biotoxin identification.
• To assess the instrument's performance in a field setting for biotoxin detection.

Main Methods:

• Development of a microchip device with two integrated separation channels (gel and zone electrophoresis).
• Utilized a microfluidic manifold with o-ring seals for reproducible fluidic connections.
• Employed laser-induced fluorescence detection with two diode lasers for low nanomolar concentration sensitivity.
• Programmable electrokinetic injection and analysis using miniature high-voltage power supplies.

Main Results:

• The instrument successfully performed simultaneous gel and zone electrophoresis on a single chip.
• Achieved detection of fluorescamine-labeled proteins at low nanomolar concentrations.
• Demonstrated portability and performance in a field laboratory test.
• The two separation methods effectively distinguished between different biotoxin variants, including ricin and staphylococcal enterotoxins.

Conclusions:

• The developed hand-held instrument offers a portable and effective solution for biotoxin detection.
• Simultaneous orthogonal microchip separations enhance the reliability of biotoxin identification.
• The system can differentiate between various forms of ricin and closely related enterotoxins.