Swing Arm Location-Controllable DNA Walker for Electrochemiluminescence Biosensing

Here, we described a novel swing arm location-controllable DNA walker based on the DNA tetrahedral nanostructures (DTNs) for nucleic acid detection using the polycyclic aromatic hydrocarbon (PAH) microcrystals (TAPE-Pe MCs) consisting of the nonplanar molecular tetrakis(4-aminophenyl)ethene (TAPE) and planar molecular perylene (Pe) as electrochemiluminescence (ECL) luminophores. Specifically, the swing arm strands and track strands were fixed simultaneously on the DTNs to obtain the locationcontrollable DNA walker, which possessed an improved reaction efficiency compared to that of a fixed swing arm-based DNA walker due to the quantitative and orderly swing arm on the DTNs. On the other hand, the Pe microcrystals doped by TAPE molecules could decrease the pi-pi stacking of Pe molecules for the ECL efficiency enhancement, achieving a blue-shifted and intense ECL emission. Therefore, we defined this enhanced and blue-shifted ECL phenomenon as inhibition of conjugation-driven ECL (IC-ECL). To prove these principles, a location-controllable DNA walker-based ECL biosensor was developed with microRNA let-7a as target molecules. The ECL biosensor achieved a low detection limit of 4.92 fM within a wide linear range from 10 fM to 100 nM. This approach offers a new insight for ECL efficiency increase and location-controllable strategies with improved reaction efficiency, demonstrating potential in diagnostic analysis.

Automated summary

A novel swing arm location-controllable DNA walker based on DNA tetrahedral nanostructures was developed for nucleic acid detection, demonstrating enhanced efficiency and potential in diagnostic analysis.