An intelligent DNA nanomachine was developed, which integrated the cyclic nucleic acid strand displacement polymerization (CNDP) and DNAzyme-mediated catalytic reaction for signal output.

Using target DNA as the fuel, the DNA machine can continuously amplify the colorimetric signal without requiring any chemical modification and without sacrificing any assay ability, resulting in the quantitative detection of p53 DNA down to 10 fM.

The proposed DNA machine for the ultrasensitive colorimetric detection of target DNA are expected to promote the potential application of DNA nanostructures in basic research and medical diagnosis.