Lowly expressed analyte in complex cytoplasmic milieu necessitates the development of non‐enzymatic autocatalytic DNA circuits with high amplification and anti‐interference performance. Herein, we engineered a versatile and robust stimuli‐responsive autocatalytic hybridization assembly (AHA) circuit for high‐performance in vivo bioanalysis. Under a moderately confined condition, the initiator motivated the autonomous and cooperative cross‐activation of cascade hybridization reaction and catalytic DNA assembly for generating an exponentially amplified readout without the parasite steric hindrance and random diffusion side effects. The AHA circuit was systematically investigated by a series of experimental studies and theoretical simulations. The successively guaranteed target recognition and synergistically accelerated signal‐amplification enabled the sensitive and selective detection of analyte, and realized the robust miRNA imaging in living cells and mice. This autocatalytic DNA circuit could substantially expand the toolbox for accurate diagnosis and programmable therapeutics.

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Rolling circle amplification (RCA) enables the facile construction of compact and versatile DNA nanoassemblies which are yet rarely explored for intracellular analysis. This is might be ascribed to the uncontrollable and inefficient probe integration/activation. Herein, by encoding with tandem allosteric deoxyribozyme (DNA-cleaving DNAzyme), a multifunctional RCA nanogel was established for realizing the efficient intracellular microRNA imaging via the successive activation of the RCA-disassembly module and signal amplification module. The endogenous microRNA stimulates the precise degradation of DNA nanocarriers, thus leading to the efficient exposure of RCA-entrapped DNAzyme biocatalyst for an amplified readout signal. Our bioorthogonal DNAzyme disassembly strategy achieved the robust analysis of intracellular biomolecules, thus showing more prospects in clinical diagnosis.

The wide extracellular-intracellular distribution of microRNA requires the on-site, robust and efficient activation of catalytic DNA circuits inside live cells. Herein, we develop an efficient non-enzymatic circuitry activation strategy to realize the orthogonally controlled catalytic DNA (CCD) circuit for achieving high-fidelity in vivo microRNA imaging through multiply guaranteed molecular recognition and progressively accelerated signal amplification. For predictable on-site activation and useful catalytic efficiency, the dominating circuitry fuel strand was initially split into inactive fuel subunits that were grafted into an auxiliary catalytic circuit. There, the in-cell-specific mRNA triggered the orthogonal amplification of the active fuel strands for sensitive target detection through the chief entropydriven catalytic DNA circuit. We believe that the on-site orthogonal circuitry activation method can contribute to clinical diagnosis and prognosis.