earticle

영어

DNAzyme (also called deoxyribozyme or catalytic DNA) is a singlestranded deoxyribonucleic acid (DNA) that contains specific catalytic activity. Various DNAzymes are used in biosensing system to detect target nucleic acid or small molecule.1 We have developed a novel target nucleic acids detection method using Cu2+-dependent DNAzyme which cleaves single-stranded DNA in the presence of copper ion.2 The triplex region of DNAzyme was modified to contain target complementary sequences. The region was separated into two parts and prolonged with sequence which can bind to target. When target nucleic acid bound to modified DNAzyme, it formed stable structure and is activated to cleave substrate DNA. However, the DNAzyme cannot form active structure without target nucleic acid. For sensitive fluorescent detection using our system, the substrate DNA for DNAzyme was labeled with a FAM fluorophore at the 5' end and a quencher at the 3' end. Quenched FAM emission of substrate DNA increased by cleavage and release of FAM-labeled substrate from active DNAzyme with target. Single-stranded artificial target was successfully detected by our system at room temperature with high selectivity. Based on our study, we believe that this simple and cost-effective detection platform can be applied to various targets detection by only change in sequence of detection probe part, while fluorophore-labeled substrate DNA is universal.