Abstract：
Cysteine (Cys), as one of the biological thiols, is related to many physiological and pathological processes in humans and plants. Therefore, it is necessary to develop a sensitive and selective method for the detection and imaging of Cys in biological organisms. In this work, a novel near-infrared (NIR) fluorescent probe, Probe-Cys, was designed by connecting furancarbonyl, as a new recognition moiety, with Fluorophore-OH via the decomposition of IR-806. The use of the furan moiety is anticipated to produce more effective fluorescence quenching because of the electron-donating ability of the O atom. Probe-Cys has outstanding properties, such as a new recognition group, an emission wavelength in the infrared region at 710 nm, a linear range (0-100 μM), a low detection limit of 0.035 μM, good water solubility, excellent sensitivity, and selectivity without the interference of Hcy, GSH, and HS-. More importantly, Probe-Cys could achieve the detection of endogenous Cys by reacting with the stimulant 1,4-dimercaptothreitol (DTT) and the inhibitor N-ethylmaleimide (NEM) in HepG2 cells and zebrafish. Ultimately, it was successfully applied to obtain images of Arabidopsis thaliana, revealing that the content of Cys in the meristematic zone was higher than that in the elongation zone, which was the first time that the NIR fluorescence probe was used to obtain images of Cys in A. thaliana. The superior properties of the probe exhibit its great potential for use in biosystems to explore the physiological and pathological processes associated with Cys.
摘要：
半胱氨酸(Cys),作为生物硫醇之一，与人类和植物的许多生理和病理过程有关。因此,有必要开发一种灵敏、选择性的检测和成像生物中Cys的方法。在这项工作中,一种新型近红外(NIR)荧光探针,探针-Cys,是通过连接呋喃羰基设计的，作为一个新的识别部分，与荧光团-OH通过IR-806的分解。由于O原子的给电子能力,预期使用呋喃部分产生更有效的荧光猝灭。探针-Cys具有突出的性质，比如一个新的识别小组，710nm的红外区域的发射波长，线性范围（0-100μM），0.035μM的低检测限，良好的水溶性，出色的灵敏度,和没有Hcy干扰的选择性，GSH,HS-。更重要的是,探针-Cys可以通过与兴奋剂1,4-二巯基苏糖醇（DTT）和抑制剂N-乙基马来酰亚胺（NEM）在HepG2细胞和斑马鱼中反应来实现内源性Cys的检测。最终,它被成功地应用于获得拟南芥的图像，发现分生组织区的Cys含量高于伸长区，这是首次使用近红外荧光探针获得拟南芥Cys的图像。探针的优异特性显示出其在生物系统中用于探索与Cys相关的生理和病理过程的巨大潜力。
