Rotary manifold for automating a paper-based Salmonella immunoassay

Area of Science:

• Food safety
• Biosensors
• Pathogen detection

Background:

• Foodborne pathogens cause significant global mortality annually.
• Current detection methods are slow, costly, and lab-dependent, hindering rapid outbreak response.
• A need exists for sensitive, field-deployable assays for agricultural product screening.

Purpose of the Study:

• To develop a user-friendly, semi-automated system for rapid pathogen detection in resource-limited settings.
• To overcome limitations of previous paper-based analytical device (μPAD) assays requiring extensive sample preparation and lab equipment.
• To demonstrate a reusable 3D-printed manifold for simplified immunoassays.

Main Methods:

• A reusable 3D-printed rotational manifold was coupled with disposable μPAD layers.
• The system semi-automates reagent delivery, washing, and detection within 65 minutes.
• Immuno-magnetic separation (IMS) was used for sample cleaning, followed by enzymatic amplification and colorimetric detection with automated image processing.

Main Results:

• The 3D-printed manifold system successfully detected Salmonella in growth media and milk.
• Detection limits were established at 4.4 × 10^2 CFU mL^-1 in growth media and 6.4 × 10^2 CFU mL^-1 in milk.
• The system demonstrated increased user-friendliness and simplified immunoassay procedures.

Conclusions:

• The 3D-printed manifold offers a practical solution for in-field pathogen detection.
• This technology enhances user-friendliness and simplifies immunoassays for commercialization.
• The developed system represents a significant step towards accessible food safety testing in resource-limited environments.