Analytical Sciences

Abstract − Analytical Sciences, 36(9), 1053 (2020).

A Water-soluble Near-infrared Fluorescent Probe for Cysteine/Homocysteine and Its Application in Live Cells and Mice
Yuhui MEN, Xiaomin ZHOU, Zhijie YAN, Linqiang NIU, Yang LUO, Jiamin WANG, and Jianhong WANG
Key Laboratory of Natural Medicine and Immuno-Engineering of Henan Province, Henan University, Kaifeng 475004, P. R. China
A near-infrared (NIR) and water-soluble probe was synthesized and studied for the detection of Cys/Hcy in aqueous solution, living cells and mice. The probe was composed of cyanine derivative as the NIR fluorescent reporting unit and pyrimidiny-thioether moiety as the Cys/Hcy responsive unit. Treatment with Cys/Hcy induced the formation of sulfur-substituted products, then intramolecular rearrangement reaction would occur to produce amino-substituted products and resulting in enhanced red fluorescence emissions. It could be applied to sense Cys/Hcy both in solution with the detection limit of 0.17 μM (or 0.32 μM) and in living cells. Cell imaging experiments proved that such a probe exhibited good cell penetration. In addition, the probe could detect Cys/Hcy in live mice with strong turn-on fluorescent response.