脱氧核酶
荧光团
分子信标
荧光
化学
水溶液中的金属离子
基质(水族馆)
生物传感器
分析物
组合化学
光化学
金属
DNA
寡核苷酸
生物化学
色谱法
物理
地质学
海洋学
有机化学
量子力学
出处
期刊:Humana Press eBooks
[Humana Press]
日期:2006-06-24
卷期号:: 275-288
被引量:12
标识
DOI:10.1385/1-59745-069-3:275
摘要
In this chapter, methods for designing metal ion sensors using fluorophore- and quencher-labeled DNAzymes are discussed. In contrast to the classical molecular beacon method based on binding, the methods described here utilize catalytic cleavage to release the fluorophore for detection and quantification, making it possible to take advantage of catalytic turnovers for signal amplification. Unlike classical molecular beacons that detect only nucleic acids, catalytic molecular beacons can be applied to different DNAzymes to detect a broad range of analytes. The methods described are based on the finding that almost all known trans-cleaving DNAzymes share a similar structure comprised of a catalytic DNAzyme core flanked by two substrate recognition arms. Using a typical DNAzyme called the "8-17" DNAzyme as an example, the design of highly sensitive and selective Pb2+ sensors is described in detail. The initial design employs a single fluorophore-quencher pair in close proximity, with the fluorophore on the 5'-end of the substrate and the quencher on the 3'-end of the enzyme. Although this sensor is highly sensitive and selective at 4 degrees C, high background fluorescence is observed at higher temperatures. Therefore a new design with an additional quencher attached to the 3'-end of the substrate is employed to suppress background fluorescence. The dual quencher method allows the sensor to perform at ambient temperatures with a high signal-to-noise ratio.
科研通智能强力驱动
Strongly Powered by AbleSci AI