Towards a lab-on-chip sensor: chemiluminescence-based DNA-nanomachine for nucleic acid detection at zeptomolar concentrations

This study presents a unique peroxidase-like DNA-nanomachine (PxDm)-based nucleic acid detection technique that could transform healthcare through providing rapid and accurate identification of infectious diseases at the point-of-care (POC) format. A fragment of S.aureus bacterium genome, responsible for nosocomial infections, was chosen as the target analyte. The PxDm has four analyte binding arms that can strongly bind and unwind nucleic acid. Only after PxDm is bound to the analyte, a G-quadruplex (G-4) structure is formed. Together with hemin, G-4 forms a DNAzyme that exhibits peroxidase activity and enhances the chemiluminescence (CL) of luminol upon oxidation by hydrogen peroxide molecules. The CL kinetic was assessed over several minutes, revealing a rapid, highly selective, and equally sensitive diagnostic procedure. The PxDm offers multiple advantages over standard diagnostic procedures, notably having the ability to detect analytes at room temperature and distinguish single nucleotide polymorphism on zeptoM concentrations. This technology may evolve into a full-fledged lab-on-a-chip device for the detection of nucleic acid markers of human diseases.