An Enzyme-Free “ON-OFF” Electrochemiluminescence Biosensor for Ultrasensitive Detection of PML/RARα based on Target-Switched DNA Nanotweezer

Abstract

Herein, an enzyme-free "ON-OFF" electrochemiluminescence (ECL) biosensor for ultrasensitive detection of fusion gene PML/RARα is constructed based on a simple target-switched DNA nanotweezer as hemin concentration controller. In this biosensor, the hemin concentration is primarily controlled by the conversion of "opened-closed" DNA nanotweezers and low concentration hemin is first used as electrochemically regenerable enhancer. In the absence of the target, the nanotweezers are in an opened state which lead to a low concentration of hemin in the solution, resulting in an enhanced Ru(bpy) 3 2+ ECL signal. In the presence of the target, the closed nanotweezers absorbed onto the surface of electrode can capture the hemin, which achieves a high concentration of hemin and then quenches the ECL signal. The developed method achieves ultrasensitive detection of PML/RARα with a wide linear range from 1 fM to 1 nM and limit of detection as low as 0.125 fM. In addition, the ECL biosensor shows excellent specificity to the other subtypes of PML/RARα (subtype "S", "V"), "PML", and "RARα". Moreover, due to the high designable character of DNA nanotweezer, this method might provide a pragmatic Ru(bpy) 3 2+ ECL platform for ultrasensitive detection of nucleic acid in the future.

Programmable DNA Tweezer-Actuated SERS Probe for the Sensitive Detection of AFB1

“…By modifying fluorescent molecules at specific tweezer arms, fluorescence resonance energy transfer can be clearly observed when operating the DNA tweezers. On the basis of this finding, a series of biosensing applications including microRNA, gene and protein analysis, and pH monitoring have been demonstrated. Interestingly, a DNA tweezer was reported to precisely tune the distance between the enzyme and cofactor which is modified at tweezer arms, leading to an enzyme nanoreactor to regulate the biofunction of the enzyme .…”

Design of Split G-quadruplex-based DNA–Bridged Nucleic Acid Chimera Nanotweezers That Recognize Short Nucleic Acids with a Single-base Mismatch

“…(25)(26)(27)(28) Also, in addition to a colorimetric method, other methods such as electrochemical detection with split Gq-based DNA-NTs were reported. (19)(20)(21) Therefore, by the combination of these methods, it is expected that split Gq-based DNA-BNA chimera NTs will be applicable to the development of POCT devices for the detection of a wide variety of nucleic acids as target recognition and signal generation elements.…”

“…(10) Because of a simple structure and principle, the split Gq-based DNA-NTs and their derivatives have also been utilized by other research groups for the detection of a protein (18) and applied to the electrochemical detection of target nucleic acids. (19)(20)(21) However, the target recognition ability of split Gq-based DNA-NTs has not been precisely investigated yet. Specifically, it is unclear whether they can recognize short nucleic acids with a single-base mismatch.…”

DNA Nanotweezers for Biosensing Applications: Recent Advances and Future Prospects

“…Similar to the above method Bian et al reported a DNA nanotweezer-based platform for detecting the fusion gene promyelocytic leukemia, retinoic acid receptor alpha (PML/RARα). 98 PML/RARα is a biomarker for acute promyelocytic leukemia, and the sensitive detection of PML/RARα is crucial for the early diagnosis of leukemia. 99,100 The biosensor is based on the ECL response by combining DTs with G-quadruplexes.…”