DNA Polymerase-Steered Self-Propelled and Self-Enhanced DNA Walker for Rapid and Distinctly Amplified Electrochemical Sensing

Abstract

The development of a simple, rapid, easy-to-operate, and ultrasensitive DNA walker-based sensing system is challenging but would be very intriguing for the enormous applications in biological analysis and disease monitoring. Herein, a new selfpropelled and self-enhanced DNA walking strategy was developed on the basis of a simple DNA polymerase-steered conversion from a typical alternate DNA assembly process. The sensing platform was fabricated easily by immobilizing only one hairpin probe (H1) and the sensing process was based on a simple one-step mixing with another hairpin-like DNA probe (H2) and DNA polymerase. The DNA polymerization could achieve target recycling and successive DNA walking steps. Interestingly, along with each DNA walking step, the new DNA walker sequence could be autonomously accumulated for a self-enhanced DNA walking effect. This provided a multilevel signal amplification ability for the ultrasensitive detection of the target with a low detection limit of 0.18 fM. Moreover, it could greatly reduce the reaction time with the sensing process finished within 1 h. The detection selectivity and the applicative potential in a complicated biological matrix were also demonstrated. Furthermore, the flexible control of sensing modes (self-enhanced DNA walking or the alternate DNA assembly) by using DNA polymerase or not offered a powerful means for sensing performance modulation. It thus opens a new avenue toward the development of a DNA walker-based sensing platform with both rapid and ultrasensitive features and might hold a huge potential for point-of-care diagnostic applications.

Proximity-Induced Bipedal DNA Walker for Accurately Visualizing microRNA in Living Cancer Cell

“…Recently, DNA, as one of the most powerful materials and a moldable building block, has become very popular for constructing artificial architectures and molecular machines owing to the exquisite programmability, specificity and predictability of Watson–Crick base pairing. − To date, various DNA nanostructures and nanomachines, such as DNA origamis, tetrahedron, gears, switches, robots, tweezers, and walkers, , have been developed, which exhibited outstanding applications in various research fields. Among them, DNA walker, a type of dynamic DNA device consisting of the drive motor, the walking track, and the walking strand, in which the walking strand can move progressively along confined walking tracks once the initial equilibrium was broken by the drive motor, has particularly aroused great interest from scientists. , Initial DNA walkers were designed to run on the predefined one-dimensional (1D) linear track and the two-dimensional (2D) planar track. − Compared with 1D and 2D DNA walker, the recently reported three-dimensional (3D) DNA walker showcases higher walking efficiency and better signal amplification performance due to the high surface-to-volume ratio and increased capacity of 3D spherical tracks. , At present, 3D DNA walker, as an ideal and powerful analytical tool, had been engineered and employed for the detection of DNA, RNA, , protein, bacteria , and metal ions .…”