Diagram of strand replacement reaction.

<p>A) Rectangular and China-map motifs (red sketches) were utilized in this reaction. B) One unhybridized capture probe was designed on each motif. C) A biotin (green cycle with a letter “B” inside) modified reporter probe was hybridized to the capture probe excluding “toe-hold” region. D) STV-QDs, as the marker in this reaction, then bound to biotin region. E) In the presence of perfectly complementary target short RNA (say miRNA-133), reporter-STV-QDs complex is replaced by target RNA eventually.