Rational construction of a DNA nanomachine for HIV nucleic acid ultrasensitive sensing.

HIV nucleic acids, one kind of significant biomarker, play an important role in fundamental studies and clinical diagnosis. Importantly, the early accurate diagnosis for HIV nucleic acids at ultralow concentrations can potentially extend the life of patients. In the current work, we developed a DNA nanomachine on gold nanoparticles (AuNPs) coupling rolling circle amplification and DNA walker cascade amplification for ultrasensitive detection of HIV nucleic acids. This DNA nanomachine sensing strategy exhibits a significantly low detection limit down to 1.46 fM. Furthermore, this DNA nanomachine biosensor is capable of detecting target DNA in real samples because of its high selectivity and sensitivity. Moreover, the DNA nanomachine biosensor is capable of discriminating single-base mismatch lower than 3.5 pM. The results showed that this DNA nanomachine biosensor has the potential for biomedical studies and clinical applications.