锶 90 是核反应堆排放的废物中最常释放的放射性产物之一。这种放射性同位素具有较长的半衰期和与钙的化学相似性，需要数百年才能衰变到可以忽略不计的水平，并且可以在食物链和骨骼中积累，从而导致严重的健康危害。因此，人们对其命运和在环境中的扩散越来越感兴趣。然而，由于缺乏表明其存在的特征能量射线，90 Sr的鉴定仍然是一个挑战。在这里，我们展示了一种能够检测 Sr 2+的生物传感器离子以超灵敏和高度选择性的方式。我们的方法利用荧光染料硫黄素 T，它触发 DNA 折叠形成鸟嘌呤四链体结构。由于这种 DNA 结构的高结合亲和力，在暴露于痕量 Sr 2+离子时，硫磺素 T 很容易被取代，导致荧光强度衰减，检测限为 2.11 nM。我们的工作可以通过提供一种技术解决方案来监测环境中放射性锶污染的传输，从而促进核电的可持续性，这是一个显着的进步，尤其是在最近的福岛核事故之后。
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Ultrasensitive and highly selective detection of strontium ions
Strontium-90 is one of the most frequently released radioactive products in waste discharged from nuclear reactors. With a long half-life and chemical similarity to calcium, this radioisotope takes hundreds of years to decay to negligible levels and can accumulate in the food chain and bones, resulting in serious health hazards. As a result, there is growing interest in its fate and dispersion in the environment. However, the identification of 90Sr remains a challenge due to the absence of characteristic energy rays signifying its presence. Here we show a biosensor that enables the detection of Sr2+ ions in an ultrasensitive and highly selective manner. Our approach takes advantage of a fluorogenic dye, thioflavin T, which triggers the folding of DNA to form guanine-quadruplex structures. Owing to the high binding affinity of this DNA structure, on exposure to a trace amount of Sr2+ ions, thioflavin T is readily replaced, leading to attenuation of the fluorescence intensity and a detection limit of 2.11 nM. Our work could contribute to the sustainability of nuclear power by providing a technological solution to monitor the transportation of radioactive strontium pollution in the environment, a notable advance, especially after the recent Fukushima nuclear incident.