Roll-to-roll fabricated self-filling polydimethylsiloxane diagnostic platforms for multiplexed pathogen nucleic acid detection

Polydimethylsiloxane (PDMS) is a commonly used material for prototyping microfluidics due to its biocompatibility, transparency, elasticity, low auto-fluorescence, and low cost in comparison to similar materials. PDMS-based devices provide alternatives for conventional diagnostic materials, such as polymerase chain reaction (PCR) tubes, that are limited in supply due to high demand in pandemics or similar situations. Roll-to-roll (R2R) production enables mass production of PDMS-based devices for point-of-care (PoC) diagnostics of pathogen nucleic acids. Mass manufacturing and end user points-of-view must be considered when designing a new assay. Isothermal nucleic acid amplification techniques enable less complex heating solutions. Self-filling of the device without external equipment, such as vacuum pumps, is also necessary for user-friendly and portable PoC devices. Here we describe a R2R-manufacturable, user-friendly (easy-to-operate and has a shelf-life of at least 6 months), self-filling and low-cost (<1 €, materials only) PDMS assay with LAMP-based and multiplexed fluorescence detection of nucleic acids from difficult sample matrixes, such as blood, for PoC diagnostics. The assay can detect up to 3 different sepsis-causing bacteria simultaneously (limit of detection, LOD, is 500 fg) from low-volume blood sample (2 µL) without pre-treatment in less than 1 h.