The lack of reliable approaches for real-time measurement and quantification of polysulfides (H2Sn) in vivo greatly limits the exploration of their potential roles in brain functions. Herein, an electrochemical probe, 4-(5-(1,2-dithiolan-3-yl)pentanamido)-1,2-phenylene bis(2-fluoro-5-nitrobenzoate) (FP2), was rationally designed and created for determination of H2Sn. The bis-electrophilic groups of FP2 could specifically recognize two −SH groups in H2Sn and trigger the generation of an electroactive pyrocatechol moiety, resulting in a well-defined faradic current signal at ∼0.24 V (vs Ag/AgCl). Meanwhile, bidentate thiols were designed as anchoring sites to greatly improve the assembled stability of FP2 at the Au surface, which efficiently defended the interference of glutathione (GSH) with a current decrease of less than 5.2% even after long-term measurements in 5 mM GSH for 3 h. In addition, a stable inner reference molecule with dithiols, α-lipoic acid ferrocenylamide (FcBT), was synthesized to construct a ratiometric electrochemical strategy for in vivo determination of H2Sn through one-step coassembling with FP2 via double S–Au bonds. The present ratiometric strategy demonstrated high selectivity for real-time tracking of H2Sn in a linear range of 0.25–20 μM. Eventually, the developed microelectrode with high selectivity, accuracy, and stability was employed for in vivo assaying of H2Sn in mouse brains with ischemia.
由于缺乏实时测量和量化体内多
硫化物(
H2Sn)的可靠方法,大大限制了对其在大脑功能中潜在作用的探索。在此,我们合理地设计并创建了一种电
化学探针--4-(5-(1,2-二
硫环戊-3-基)戊
氨基)-1,2-亚苯基双(
2-氟-5-硝基苯甲酸酯)(
FP2),用于测定 。 的双亲电基团可特异性识别 中的两个 -SH 基团,并引发生成具有电活性的焦
儿茶酚分子,从而在 ∼0.24 V(相对于 Ag/AgCl)的电压下产生明确的法拉第电流信号。同时,设计了双叉
硫醇作为锚定位点,大大提高了 在
金表面的组装稳定性,从而有效地抵御了
谷胱甘肽(GSH)的干扰,即使在 5 mM GSH 中长期测量 3 小时,电流下降率也低于 5.2%。此外,还合成了一种稳定的二
硫醇内参分子--
α-硫辛酸二茂铁酰胺(FcBT),通过双 S-Au 键与 一步共组装,构建了体内测定 的比率电
化学策略。目前的比率测量策略在 0.25-20 μM 的线性范围内表现出了对 实时跟踪的高选择性。最后,所开发的微电极具有高选择性、准确性和稳定性,可用于缺血小鼠大脑中 的体内检测。