The label- and laser-free autocatalytic nucleic acid amplification reaction for the sensitive miRNA detection

Abstract

MicroRNAs (miRNAs) are increasingly recognized as vital biomarkers for cancer, given their aberrant expression patterns in oncogenesis. Sensitive detection of these miRNAs is imperative for early-stage cancer diagnostics. Current fluorescence-based assays, while effective, are limited by the need for costly labeling and external laser sources, contributing to elevated autofluorescence background signals. Our study introduces a label- and laser-free, chemiluminescence-based, autocatalytic DNA circuit composed of catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR), offering a sensitive and accurate approach to miRNA detection. The target T initiates CHA, generating multiple dsDNA products with exposed initiator I sequences. I triggers HCR to form long nanowires encoded with intact T and hemin/G-quadruplex DNAzyme structures, respectively, leading to self-catalytic cycles and amplified chemiluminescence signal output. By integrating auxiliary recognition hairpin, this autocatalytic chemiluminescence method enables the sensitive detection of miRNA. Overall, our sensitive and accurate miRNA assay provides a novel tool for the early diagnosis of cancer.