A Direct, Multiplex Biosensor Platform for Pathogen Detection Based on Cross-linked Polydiacetylene (PDA) Supramolecules

This study focuses on the development of a multiplex pathogen-detection platform based on polydiacetylene (PDA) using a novel immobilization procedure. PDA liposome-based solid sensors have a critical drawback as the PDA liposomes are not stably immobilized onto the solid substrate. Therefore, to overcome this problem, an interlinker, ethylenediamine, is introduced, which acts as a cross-linker between individual PDA liposomes. The quantity of ethylenediamine added was optimized to 1 mm, as measured by the fluorescence signal emitted by the stably immobilized PDA liposomes, a concentration at which the fluorescence signal is 10 times higher than for the resulting PDA chips made without the interlinker. This procedure is used to manufacture PDA liposome-based multiplex biosensor arrays for well-known water and food-borne pathogens. The fabricated biosensor was able to perform the simultaneous and quantitative detection of 6 species of pathogens. As such, the results demonstrated from this research can be exploited for the development of more advanced PDA-based biosensors and diagnostics.