Versatile Electrochemical Biosensor Based on the Target-Controlled Capture and Release of DNA Nanotubes for the Ultrasensitive Detection of Multiplexed Biomarkers

Abstract

Herein, an ultrasensitive and versatile electrochemical biosensor was developed through the target-controlled capture and release of signal probe-loaded DNA nanotube for the ultrasensitive detection of two different types of cancer-related biomarkers, microRNA-21 (miRNA-21) and glutathione (GSH). In this system, target 1 (miRNA-21) first triggered duplex-specific nuclease (DSN)-assisted recycle amplification to generate numerous disulfide-linked DNA strands (DL), which could effectively capture DNA nanotube to immobilize methylene blue (MB) to produce remarkable electrochemical signals and achieve the ultrasensitive detection of miRNA-21 with a detection limit down to 32.6 aM. Furthermore, in the presence of target 2 (GSH), the electrochemical signal was significantly reduced by a thiol–disulfide bond exchange reaction on DL to release MB-immobilized DNA nanotubes away from the sensing interface, which enabled the sensitive analysis of GSH with a detection limit of 0.379 nM. Impressively, this strategy could achieve ultrasensitive detection of different types of biomarkers to prominently lessen false-positive responses from the current sensing methods toward a single biomarker or the same type of biomarker and remarkably heighten the accuracy and precision of early cancer diagnosis. Meanwhile, the proposed electrochemical biosensor made it possible to realize the regenerative analysis of targets over four times without extra fuel, which could conspicuously improve the analytical efficiency compared with that of traditional biosensing assays. As a result, this study might open up novel insights to design a versatile and multifunctional sensing platform and encourage deeper exploration for detecting different types of biomarkers in the fields of early disease diagnosis and biochemical research.

High-Efficiency 3D DNA Walker Immobilized by a DNA Tetrahedral Nanostructure for Fast and Ultrasensitive Electrochemical Detection of MiRNA

“…However, in comparison, the change of SWV signal was unobvious in the blank sample or HeLa cells even with a large number (10 000), showing the quite low level in HeLa cells. Moreover, RT-PCR analysis (Figure S5) as the gold standard method for miRNA detection was also used to successfully cross-verify the results in Figure and the obtained results were in line with those of previous reports, − in conclusion, suggesting that this approach we proposed to analyze the expression of miRNA-21 in real cancer cells can indeed realize a significant potential for ultimate clinical diagnosis in different cancers.…”

Corn-Based Fluorescent Light-Up Biosensors with Improved Signal-to-Background Ratio for Label-Free Detection of Long Noncoding RNAs

“…When lncRNA MALAT1 is present, lncRNA MALAT1 can bind with the complementary domain of capture probes to obtain the capture probe/MALAT1 heteroduplex on the surface of MB. Subsequently, DSN selectively digests the complementary domain of capture probes in the capture probe/MALAT1 heteroduplex, 34 leading to the liberation of lncRNA MALAT1 and T7 promoter sequences from the MB-capture probe conjugate. The free lncRNA MALAT1 binds with new biotinylated capture probe to initiate the cyclic digestion of capture probes, liberating abundant T7 promoters.…”

Ultrasensitive Photocathodic Biosensor Based on the Cu2O/PTB7-Th/PDA+ Composite with Enhanced Photoelectrochemical Performance for the Detection of MicroRNA-375-3p

“…Recently, various DNA amplifying strategies have been reported to enhance the sensitivity of PEC biosensors. − Among them, three-dimensional (3D) DNA walkers have been widely concerned because of the multiple recognition domains and the increased capacity in mimicking complicated biological systems. , Nonetheless, the signal amplification efficiency of 3D DNA walkers is still restricted by the low walking efficiency due to the heterogeneity and local disordered distribution of swinging arms and bundles on the surface. , Thus, it is important to search for an appropriate DNA amplifying strategy that can be combined with 3D DNA walkers to improve the amplification efficiency. DHCR is a modified HCR form, where the traditional hairpin structure fuel chains are replaced by the dumbbell structure DNA .…”