Modular probe-based colorimetric miRNA detection via polymerase/endonuclease assisted chain displacement.

ABSTRACT

Methods for sequence-specific microRNA (miRNA) analysis are crucial for miRNA research and guiding nursing strategies. We have devised a colorimetric technique for detecting miRNA using a dumbbell probe-based polymerase/endonuclease assisted chain displacement, along with silver ions (Ag+) aptamer assisted color reaction. The suggested approach enables precise measurement of miRNA-21 within the concentration range of 100 fM-5 nM, with a low detection limit of 45.32 fM. Additionally, it exhibits exceptional capability in distinguishing variations at the level of individual nucleotides. Furthermore, the detection technique may be utilized to precisely measure the amount of miRNA-21 in serum samples, demonstrating a high level of concordance with the findings obtained from a commercially available miRNA detection kit.

This method utilizes the hairpin structure in the dumbbell probe to significantly enhance the accuracy of target recognition in the polymerase/endonuclease assisted chain displacement strategy. As a result, the method gains a superior capability to discriminate between target miRNA and interfering miRNAs. The combination of target recycling and the polymerase/endonuclease assisted chain displacement strategy allows for highly sensitive analysis of miRNA, which is either superior or comparable to previous colorimetric methods for miRNA detection. This approach is simple, economical and extremely specific for detecting miRNA. It holds great potential for clinical use, particularly in guiding the adaptation of nursing techniques.