A Disposable, Cyclo-Olefin Copolymer, RNA Microfluidic Sensor for Bacteria Detection

This contribution outlines the design and manufacturing of a biosensor for retrieval and detection of bacteria RNA, performing both bacteria lysis and analysis in the same device. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and hot-embossing manufacturability. The RNA retrieval is carried on after bacteria on-chip heat-lysis by a screen-printed silver micro-heater. Two additional carbon-based, resistive temperature sensors, printed on the chip sealing film, monitor the heating and cooling process before the analysis reaction. The analysis reaction, that takes place in a subsequent temperature controlled reaction chamber, consists on the hybridization of the released RNA to nucleic acid capture probes prepared on the COC substrate surface. Later, the identification is completed by detection of fluorescence intensity from captured RNA by using a photon counter sensor. For this work, experimental results using E. Coli off-chip and on-chip extracted RNA shows that bacterial heat-lysis, analysis through hybridization and fluorescence detection can satisfactorily take place on a single device made of COC.