Swing Arm Location-Controllable DNA Walker for Electrochemiluminescence Biosensing

Abstract

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 location-controllable 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 π–π 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.

Quadrilateral Nucleic Acid Frame-Accelerating DNAzyme Walker Kinetics for Biosensing Based on Host–Guest Recognition-Enhanced Electrochemiluminescence

“…However, the random assembly of the walkers and tracks is unfavorable for effective collision, reducing the reaction kinetics. By virtue of superior mechanical rigidity and rich modification sites of the frame nucleic acid, our group 7 designed a tetrahedral DNA nanostructure-assisted locationcontrollable DNA walker with high efficiency, paving the way for sensitive detection of biomarkers. Despite the DNA walker presenting high controllability, the stumbling block is the dependence of nuclease as the driving force, which is of high cost and is vulnerable to environmental interference, restricting its further application in bioanalysis.…”

Advances in Electrochemiluminescence Biosensors Based on DNA Walkers

“…However, confined walking strands and tracks are still facing the randomness and disorder of the spatial assembly, resulting in unsatisfactory collision due to the collapse and entanglement on the surface, which are the intrinsic drawbacks of DNA strands to impede the moving efficiency. Very recently, Liao et al [45] designed a tetrahedral DNA nanostructure-supported (TDNA nano-supported) DNA walker, in which both walking strands and tracks were confined on the tetrahedral DNA nanostructures (Figure 9). On account of the good rigidity of tetrahedral DNA nanostructures, the position of walking strands and tracks could be relatively anchored in contrast to random tracks and walking strands, which decreased the risk of walking strands deviating from the tracks during moving process.…”

Advances in Designer DNA Nanorobots Enabling Programmable Functions

“…[59] The autonomous operations carried out by continuously stepping DNA walkers can be utilized as signal amplifiers for ultrasensitive detection of the targets as well as cellular analysis and visualization in living cells. [56] For instance, hybridization (CHA [60] and TMSDR) -and enzyme-powered [61] DNA walkers have been utilized for ultrasensitive biosensing functions. Compared with the hybridization, enzyme-powered continuous actuation exhibits a much faster reaction rate and kinetics, [59] holding great promise in rapid analysis.…”