Visual detection of STAT5B gene expression in living cell using the hairpin DNA modified gold nanoparticle beacon

► The special sequence of hairpin DNA for human STAT5B mRNA was designed by bioinformatical method. ► The quenching efficiency up to 90%. ► The prepared beacon is stable inside cells. ► The beacons were uptaken by cell without any transfection agents. ► Using this beacon, the expression of the STAT5B gene was successfully detected in living MCF-7 cells.