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开发了一种简单快速的荧光探针,该探针在DNA的3’端标记荧光素并利用[T-Hg(II)-T]复合结构对荧光进行猝灭,荧光素与[T-Hg(II)-T]复合结构之间发生荧光共振能量转移。在对探针链长度以及pH和反应时间等实验条件进行优化后,该荧光探针对汞离子具有较高的选择性,用于汞离子分析时检出限可以达到纳摩尔级。当加入半胱氨酸,由于形成了半胱氨酸-汞离子复合结构,[T-Hg(II)-T]复合结构被破坏,荧光强度大量的恢复。利用此原理可以对半胱氨酸进行分析,检出限也可以达纳摩尔级。该荧光探针利用一条廉价的T碱基适配体链所构筑,相比传统的荧光探针有着独特的优势。
A simple and rapid fluorescent probe was developed that fluoresces on the 3 ’end of the DNA and quenches the fluorescence using [T-Hg (II) -T] complex. Fluorescein is bound to [T-Hg (II) -T] fluorescence resonance energy transfer occurs between the composite structure. After optimization of experimental conditions such as probe chain length, pH and reaction time, the fluorescent probe has high selectivity to mercury ion, and the detection limit of mercury ion can reach nanomolar level. Upon addition of cysteine, the complex of [T-Hg (II) -T] was destroyed due to the formation of a cysteine-mercury ion complex and a large amount of fluorescence intensity was recovered. Cysteine can be analyzed using this principle and the detection limit can also be nanomolar. This fluorescent probe is constructed using an inexpensive T-base aptamer chain and offers unique advantages over traditional fluorescent probes.