CaCO₃ nanoparticle-encapsulated CHA circuits for sensitive fluorescence detection of miRNA in living cells

MicroRNAs (miRNAs) serve as important biomarkers for various diseases, including malignant tumors, and have broad applications in diagnosis, treatment, and prognosis. The development of real-time in situ imaging methods for monitoring miRNAs has both scientific and clinical value, and in this regard, catalytic hairpin assemblies (CHAs) can be used as precise and efficient nucleic acid circuits that facilitate hybridization without depleting targets. In this study, we developed a detection system based on CHA circuits encapsulated within CaCO₃ nanoparticles, which represents a novel strategy for the detection of human pancreatic cancer. This encapsulation facilitates the pH-sensitive release of DNA probes, thereby ensuring the selective and sensitive detection of cancer-associated miRNAs. Our experimental results confirmed that the fabricated nanoparticles contributed to enhancing the stability and performance of the DNA circuits, thereby enabling precise miRNA detection and effective discrimination between cancerous and non-cancerous cells. Our findings in this study highlight the potential utility of CaCO₃ nanoparticle-encapsulated CHA circuits for advancing miRNA-based cancer diagnostics and therapeutics.