Detection ofbased on a catalytic hairpin self-assembly reaction combined with gold nanoparticle colorimetry.

Recent studies have shown that abnormalexpression is a rule, rather than an exception, in cervical cancer and can be used as a diagnostic and prognostic biomarker to assess tumor initiation. In this study, we developed a general, sensitive strategy for detectingusing catalytic hairpin self-assembly (CHA) combined with gold nanoparticles (AuNP) colorimetry. The presence oftriggers the repeated self-assembly of two designed hairpin DNAs (H1 and H2) into dsDNA polymers, which leads to changes in the surface plasmon resonance absorption band and the macroscopic color of the AuNP colloids due to the formation of nanoparticle-DNA conjugates. This experimental phenomenon can be observed by ultraviolet-visible spectrometry or even with the naked eye. Using this method,could be quantitatively detected at the picomolar level (as low as 20.7 pM). Compared with traditional methods, such as quantitative polymerase chain reaction and RNA blotting, this strategy has a simple operation, low cost, and high sensitivity and selectivity, and thus, exhibits significant potential for miRNA detection.