Target-induced DNA nanomachine operation for the detection of proteins

Accurate and sensitive detection of disease-associated proteins in early stage of patients plays an important role in timely treatment and successfully extending patients' lives. To meet this demand, we herein rationally designed a flexible target-induced DNA nanomachine operation (TIDNMO) sensor for the detection of proteins. The TIDNMO system was composed of DNA nanoswitch and DNA walker. Triplex DNA nanoswitch was triggered by specific target, followed by the release of the walking strand, which initiated the DNA walker amplification as signal output. In addition, the Exo III could drive walking strand autonomously move on gold nanoparticle surface to realize 2 orders of magnitude signal amplification. What's more, this sensor could transform its suitable functional recognition element of DNA nanoswitch to recognize other specific molecule and realize different targets sensing based on identical walking tracks. Considering the facile reporter elements and efficient amplification performance, the present DNA nanomachine as a sensor could achieve a detection limit of 68 pM for anti-Dig antibody, 0.95 pM for mucin-1 respectively, along with a superb specificity. Furthermore, the method reported here opened a new chapter in disease-related protein sensing for the development of clinical early diagnosis.