posted on 2021-12-24, 15:04authored byYinjie Qian, Limin Zhang, Yang Tian
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.