A quencher-free DNAzyme beacon for fluorescently sensing uranyl ions via embedding 2-aminopurine

Publication date: Available online 15 April 2019Source: Biosensors and BioelectronicsAuthor(s): Xiaolong Wang, Rui Zeng, Shengnan Chu, Wei Tang, Na Lin, Jun Fu, Jiangrong Yang, Bo GaoAbstractDNAzyme-based fluorescent probes have provided valuable protocols for detecting uranium, one of the most common radioactive contaminants in the environment, with ultra-high selectivity and sensitivity. Designing novel DNAzyme beacons to update the mode of fluorescence reporting and/or quenching will continuously enhance “turn-on” sensing performance as well as promote actual application of the biological probes. In this work, we developed a novel quencher-free DNAzyme beacon by embedding fluorescent 2-aminopurine for rapid detection of uranyl ion. 2-aminopurine is able to substitute adenine and keep strong fluorescence in single-stranded DNA whereas being quenched in the hybridized double-stranded DNA by the base-stacking interaction. The combination of such trait of 2-aminopurine and cleavage reaction of DNAzyme in the presence of target co-factors possesses two main advantages for ion sensing: simplicity for avoidance of extra quencher groups and high performance because of superiority of DNAzyme essence. The experimental conditions including embedding site, pH and salt concentration of buffer solutions, and the amount ratio of enzyme strand to substrate strand used to form DNAzymes were systematically optimized to inspire the highest performance of the biological beacon. Thus, a de...
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research