Construction of DNA walker nanomachine aptasensor for the simultaneous detection of dual-cancer biomarkers

Abstract

While it is recognized that early diagnosis of cancer-related biomarkers can become an effective avenue for timely treatment and successfully improve patient survival, it remains challenging to get accurate inspection results. Currently, most reported cancer biomarkers sensing methods are only focused on one type biomarker quantitative detection, making it difficult for the accurate medical diagnostics. In this work, we constructed a DNA walker nanomachine aptasensor based on gold nanoparticles for the dual-cancer biomarker simultaneous sensing. The aptamers, labelled with the fluorophore, hybridized with the complementary strands on gold nanoparticle surface, serving as the walking track. Target analytes could respectively bind its aptamers and lead to the dissociation of unstable double-strand spherical nucleic acid. Exonuclease I (Exo I) selectively digested the aptamer which bound with target analytes, then the released targets go back to the next spherical nucleic acid track for walking. The use of spherical nucleic acid probes improved the high-sensitivity detection for the analyte. Exo I provided a driving power for target recycling and significantly improve the sensitivity of the aptasensor as well. The DNA walker nanomachine aptasensor was successfully applied in the detection of carcinoembryonic antigen (CEA) from 0.167 to 3.34 ng/mL, and mucin-1 (MUC-1) from 0.167 to 16.67 ng/mL, respectively. Moreover, we used the two aptamers to construct the DNA walker nanomachine, and achieved the simultaneous detection of CEA and MUC-1, having great potential for the biomolecular logic gate construction and early diagnosis of disease.