Detection of periodontal pathogens on R2R fabricated foil-based chips - comparison of chemiluminescent and electrochemical detection

• Achieved reproducible roll-to-roll (R2R) fabrication of FoldChips • Shelf-life of the chips up to 56 days could be demonstrated • Validated EC and CL assays across six different DNA standards in buffer solutions • Enabled cell-based bacterial detection using room-temperature ionic-liquid lysis • Demonstrated EC and CL detection of two bacterial species (E. coli and Pi). Periodontitis is a widespread inflammatory oral disease that requires rapid and accurate diagnosis in order to achieve better therapeutic outcomes. For this purpose, biosensors embedded in microfluidics offer great potential for the development of rapid tests. This study reports on the development of R2R fabricated microfluidic chips for enzyme-based nucleic acid detection using electrochemical (EC) and chemiluminescent (CL) detection. The chips were tested using DNA standards in buffer solution specific to the parameter of total germ load (TGL), Prevotella intermedia ( Pi ), Aggregatibacter actinomycetemcomitans ( Aa ), Porphyromonas gingivalis ( Pg ), Treponema denticola ( Td ), and Tannerella forsythia ( Tf ). Both, EC and CL detection, exhibited dynamic ranges of 0.01–25 nM. However, CL showed higher sensitivity and reproducibility (LOD-span of 12–120 pM) than EC (LOD-span of 2 pM–1.2 nM), with the best LODs achieved for TGL (0.05 nM CL, 0.03 nM EC) and Pg (0.01 nM CL, 0.02 nM EC). Cell detection based on ribosomal RNA analysis was evaluated using Escherichia coli cells as TGL parameter and Pi cells, applying ionic liquid–based lysis at room temperature. Here, EC detection showed improved sensitivities (LOD E.coli 3.44×10 4 cells/µL and LOD Pi 5.6×10⁵ cells/µL) compared to CL (LOD E.coli 9.7×10 4 cells/µL and LOD Pi 1.03×10 6 cells/µL). Overall, the findings underscore the chip’s potential as a sensitive, versatile platform for point-of-care diagnostics in periodontology.