Fluorescent detection of brown spot of tobacco caused by based on lambda exonuclease-induced DNAzyme amplification.

A rapid, simple, and sensitive fluorescent detection method for brown spot of tobacco is established by lambda exonuclease-induced Mg-dependent DNAzyme amplification. It contains hybridization of the genome and HP1, digestion of the 5'-phosphorylated strand of the hybrid dsDNA by lambda exonuclease, acquisition of complete Mg-dependent DNAzyme, cleavage of the substrate modified with FAM and BHQ-1, and fluorescent detection. The proposed assay exhibits good sensitivity (10 pg L), selectivity and reproducibility.