Universal Detection and Imaging for Multiple Targets by Coupling Target-Primed Nicking-Enhanced Rolling Circle Amplification with Self-Powered DNAzyme Walker

Abstract

Although promising in monitoring low-abundance analytes, most of the DNAzyme walker is only responsive to a specific target. Herein, a universal, ready-to-use platform is developed by coupling nicking-enhanced rolling circle amplification and a self-powered DNAzyme walker (NERSD). It addressed the issues that DNAzyme strands need to be specifically designed for different biosensing system, allowing highly sensitive analysis of various targets with the same DNAzyme walker components. It is also specific owing to target-dependent ligation of the padlock probe and precise cleavage of a substrate by a DNAzyme strand. As typically demonstrated, the strategy has an equivalent capacity with the qRT-PCR kit in distinguishing plasma miR-21 levels of breast cancer patients from normal subjects and is able to differentiate intracellular miR-21 and ATP levels by confocal imaging. The approach characteristic of programmability, flexibility, and generality indicated the potential in all kinds of biosensing and imaging platform.

Isothermal Reciprocal Catalytic DNA Circuit for Sensitive Analysis of Kanamycin

“…The ingenious integration of multiple amplicons could compensate for the limitations of individual amplicons and fully utilize their strengths, thus substantially improving the amplification efficiency. Some multilayered DNAzyme-involved CHR systems have been constructed, while the cofactor-dependent feature and the vulnerable substrate limited their widespread biosensing applications. , RCA involves the continuous replication of the complementary sequence of the circular DNA template through the successive lengthening of a primer strand in the presence of polymerase and dNTPs, resulting in the generation of long DNA nanowires. − With its simple design, low signal leakage, and high amplification efficiency, RCA becomes an ideal candidate for integration with the CHR amplicon to construct a robust reciprocal catalytic DNA circuit. Therefore, it is expected that a universal and powerful reciprocal catalytic circuit could enable high-performance biosensing in complex food matrices.…”

“…Programmable DNA amplification circuits have emerged as a powerful tool for monitoring food contaminants. − These circuits usually operate at a constant temperature, including catalytic DNA assembly (CDA), − cascade hybridization reaction (CHR), − DNAzyme-catalytic reactions, − and rolling circle amplification (RCA). − CHR mediates the cross-opening of hairpin reactants in response to a trigger, resulting in the formation of long copolymers . It exhibits moderate amplification capability, low cross-talk, and easy integration with FRET transduction for providing a readout signal.…”

Long-Wavelength Illumination-Induced Photocurrent Enhancement of a ZnPc Photocathodic Material for Bioanalytical Applications

“…In this work, we synthesized a novel PTB7-Th/ZnPc sensitization structure with accelerated inter/intramolecular electron transfer capability to significantly enhance the photoelectric conversion efficiency for acquiring strong photocurrent signals, providing ideal photocathode materials for fabricating high-performance photoelectrochemical (PEC) biosensors. In recent years, rolling circle amplification (RCA) as a highly specific isothermal method has attracted much attention because of the generation of periodic oligonucleotides. , Furthermore, the RCA reaction has the merit of high specificity involved in rigid initiation conditions between the template and the primer, which is highly promising for signal amplification strategies. , …”

Programmable Entropy-Driven Circuit-Cascaded Self-Feedback DNAzyme Network for Ultra-Sensitive Fluorescence and Photoelectrochemical Dual-Mode Biosensing

“…These low-cost amplification strategies are typically capable of achieving 100-fold signal gain in a few hours, but their amplification capabilities are still insufficient given the interference of complex environments to organisms and the low abundance of targets. As a result, a series of DNA cascade networks such as CHA-DNAzyme, , HCR-DNAzyme, , CHA-HCR, , RCA-DNAzyme, , CRISPR/Cas12a-HCR, and CRISPR/Cas12a-SDA have been developed to further enhance signal amplification and thus increase detection sensitivity. However, the metastable hairpin structure may cause undesirable DNA self-assembly to occur and produce background leakage, while the introduction of DNA polymerases often produces nonspecific amplification.…”