Detecting miRNA-21 using dual-mode biosensor via click chemistry-mediated variable temperature amplification reaction

miRNAs regulate several life activities and they have emerged as biomarkers in cancer diagnosis. Pursuing highly sensitive sensing platforms for detecting miRNAs, signal amplification strategies are the most frequently utilized means. In this research, a click chemistry-mediated variable temperature amplification (CCVTA) biosensor was developed for the highly selective and sensitive detection of miRNA-21. Sensing depended on enzyme-free amplification and copper-free type click chemistry, which greatly simplified the pre-treatment procedure and the conditions for sensing. In addition, the amplification products were used to output two signals, which are electrochemical and colorimetric modes. The dual-mode biosensor respectively achieved a detection limits of 0.57 and 17.19 fmol/mL, as well as excellent selectivity, stability, and applicability. It can be expected that CCVTA-biosensor sparkle with attractive prospects in the sensing field.