Molecular beacon (MB) is especially suited to detection of single nucleotide polymorphism (SNP), and the type of MB immobilized on the surface of microarray in particular, may detect multi-sample and multi-locus.However, the majority of MB needs to be labeled with fluorescence and quenching molecules on the two ends of the probe, and observed the reaction of fluorescence or complicated electrochemical signal produced hybridization of MB and target sequence by complex and expensive instruments.