Enzyme-Free Autocatalysis-Driven Feedback DNA Circuits for Amplified Aptasensing of Living Cells

Abstract

Aptasensors with high specificity have emerged as powerful tools for understanding various biological processes, thus providing tremendous opportunities for clinical diagnosis and prognosis. However, their applications in intracellular molecular imaging are largely impeded due to the low anti-interference capacity in biological environments and the moderate sensitivity to targets. Herein, a robust enzyme-free autocatalysis-driven feedback DNA circuit is devised for amplified aptasensing, for example, adenosine triphosphate (ATP) and thrombin, with a significantly improved sensitivity in living cells. This initiator-replicated hybridization chain reaction (ID-HCR) circuit was acquired by integrating the HCR circuit with the DNAzyme biocatalysis. Also, the autocatalysis-driven aptasensor consists of a recognition element and an amplification element. The recognition unit can specifically identify ATP or thrombin via a versatile conformational transformation, resulting in the exposure of the initiator to the autocatalysis-driven circuit. The ID-HCR element integrates the charming self-assembly characteristics of the HCR and the remarkable catalytic cleavage capacity of DNAzyme for realizing the continuously self-sustained regeneration or replication of trigger strands and for achieving an exponential signal gain. The autocatalysis-driven aptasensor has been validated for quantitative analysis of ATP and thrombin in vitro and for monitoring the corresponding aptamer substrates with various expressions in live cells. More importantly, the autocatalysis-driven aptasensor, as a versatile amplification strategy, holds enormous potential for analysis of other less abundant biomarkers by changing only the recognition element of the system.

Closed Cyclic DNA Machine for Sensitive Logic Operation and APE1 Detection

“…Recently, autocatalytic hybridization assembly represented a promising strategy to perform cooperatively facilitated cycle assembly and realize signal amplification with the theoretically highest amplification capacity. [28][29][30][31][32] This strategy provides a new vision for advanced signal amplification and is expected to be extensively applied in ultrasensitive logic operation and molecular recognition.…”

Programming DNA Reaction Networks Using Allosteric DNA Hairpins

“…The increase in the numbers of functional nucleic acids could not only extend the signal output manners but also enhance the function of the network. Gao et al [ 51 ] proposed a DNAzyme-based biosensor network, which uses a strategy that four substrate hairpins to generate a kind of DNAzyme structure. Following this way, we used three substrate hairpins in our generation strategy.…”

Stimuli‐Responsive RNA‐Cleaving DNAzyme for Biomedical Application

“…A wide range of DNAzyme‐based sensors have been reported for nucleic acid detection [63–69] . The detection sensitivity could be improved through the coupling of other nucleic acid amplification processes with DNAzymes.…”

“…A wide range of DNAzyme-based sensors have been reported for nucleic acid detection. [63][64][65][66][67][68][69] The detection sensitivity could be improved through the coupling of other nucleic acid amplification processes with DNAzymes. Wang et al developed an isothermal protease-free CHA-HCR-DNAzyme cascade circuit for miRNA detection and intracellular imaging.…”