Three-in-one: A pre-tetrahedral DNA biosensor for vascular endothelial growth factor (VEGF) mRNA detection, imaging,...

Vascular endothelial growth factor (VEGF) mRNA has garnered widespread attention as an important biomarker for disease diagnosis and treatment. However, the rapid and sensitive monitoring of its expression levels remains challenging. Herein, we have developed a pre-tetrahedral DNA (pre-TDN) biosensor for in vitro detection, in situ imaging and immobilization of VEGF mRNA. The pre-TDN biosensor was composed of a FAM-labeled pre-TDN structure and a short DABCYL-labeled DNA strand. The pre-TDN structure was self-assembled from three of the four tetrahedral DNA strand typically forming a tetrahedral DNA nanostructure. The presence of VEGF mRNA as the fourth strand completes the assembly into a tetrahedral nanostructure, leading to fluorescence emission. This biosensor has a limit of detection (LOD) of 1.01 nM. In addition, it enables intracellular specific imaging while simultaneously suppressing VEGF mRNA expression, extending therapeutic possibilities for related diseases. In conclusion, the pre-TDN biosensor for VEGF mRNA detection system provides a general analytical idea for the detection of other mRNAs, which is expected to be applied to the diagnosis and treatment of clinical diseases.