Detection of long mRNA sequences by a Y-shaped DNA probe with three target-binding segments

Tumor-related mRNA detection is significant and interesting. The current mRNA detection method has the challenge of quantifying long mRNA sequences. Herein, a Y-shaped DNA probe with three target-binding segments was developed to detect tumor-related mRNA. This Y-shaped DNA probe (Y-probe) was assembled by six single DNA strands. Among these DNA strands, two DNA strands contained the split G-quadruplex sequence, and two DNA strands were modified with a pair of fluorophore and quencher, which were used to produce the detectable signal. In the presence of a long target mRNA sequence, target mRNA was hybridized with the three target-binding segments of the Y-probe, resulting in the increased fluorescence of G-quadruplex specific dye Thioflavin T and the decreased fluorescence of fluorophore, which could achieve the ratio detection of target mRNA. The Y-probe exhibited a low detection limit of 17.53 nM. Moreover, this probe showed high accuracy due to the benefits of three target-binding segments.