Department of Chemical Sciences , University of Padova , Via Marzolo 1 , 35131 Padova , Italy.
ACS Sens. 2019 Nov 22;4(11):3080-3083. doi: 10.1021/acssensors.9b01358. Epub 2019 Nov 13.
Recently, a new water-soluble, fluorescein-based probe for the detection of superoxide radical anion in aqueous media was developed by Lu et al. (. , , 59-64). The probe was proven to be selective for superoxide and was used successfully also in cells and zebrafish embryos. To characterize the response of the probe to superoxide, Lu et al. used KO dissolved in deionized water as a surrogate. In testing this probe in different applications, we repeated some of these experiments and came to realize that the fluorescence signal observed by the Authors in their experiments with KO was incorrectly attributed to the reaction of the probe with superoxide and is due instead to its reactions with HO and HO. We show that indeed under the conditions used in these assays KO undergoes very fast reaction with water to form HO and HO. On the other hand, by using a proper surrogate, namely, KO dissolved in DMSO, and spin trapping experiments, we confirmed the ability of the probe to detect superoxide.
最近，Lu 等人开发了一种新的水溶性、基于荧光素的探针，用于检测水相介质中的超氧阴离子自由基。该探针被证明对超氧阴离子具有选择性，并且在细胞和斑马鱼胚胎中也成功地得到了应用。为了表征探针对超氧阴离子的响应，Lu 等人使用溶解在去离子水中的 KO 作为替代物。在重复这些实验并应用该探针的过程中，我们意识到作者在他们的 KO 实验中观察到的荧光信号被错误地归因于探针与超氧阴离子的反应，而实际上是由于其与 HO 和 HO 的反应。我们证明，在这些实验中使用的条件下，KO 确实会与水快速反应生成 HO 和 HO。另一方面，通过使用适当的替代物，即溶解在 DMSO 中的 KO 以及自旋捕获实验，我们证实了该探针检测超氧阴离子的能力。
