Fluorescent probe for near infrared detection of cysteine as well as preparation method and application of fluorescent probe

Abstract

The invention provides a fluorescent probe with the advantages of reduced background interference, high sample penetration performance, good selectivity, high sensitivity and good imaging resolution for fluorescence open-close type near infrared detection of cysteine as well as a preparation method and application of the fluorescent probe. The fluorescent probe is subjected to fluorescence quenching by taking near infrared fluorescent parent nucleus containing a plurality of double bonds as a fluorophore and taking 2,4-dinitrobenzene sulfonamide as a quenching unit; in actual detection, in thepresence of the cysteine, sulfydryl of the cysteine carries out nucleophilic substitution reaction on electron deficient aromatic ring, a sulfonamide bond cracks and a fluorescence quencher is dissociated, so that the fluorescent probe without fluorescence or with weak fluorescence based on intramolecular charge transfer (ICT) process releases the fluorescent parent nucleus, fluorescence is enhanced or opened to generate a fluorescent signal for selectively recognizing the cysteine, and further the aims of selective recognition and analysis and detection of the cysteine (Cys) are achieved.

Description

technical field [0001] The invention relates to the technical field of chemical analysis and detection, in particular to a fluorescence "off-on" near-infrared fluorescent probe for detecting cysteine, a preparation method and application thereof. Background technique [0002] There are a variety of important small molecule sulfhydryl compounds in organisms, and cysteine ​​(Cys) is the only natural essential amino acid containing sulfhydryl (-SH), and is an important component of protein synthesis. The content of cysteine ​​in the body is closely related to many physiological diseases, such as Alzheimer's disease and cardiovascular disease. Therefore, the content of cysteine ​​can be used as one of the basis for the diagnosis of such diseases. At the same time, a detailed understanding of the generation, distribution and level fluctuation of cysteine ​​(Cys) is of great significance to the research of cell activity, body physiology and pathology. Important scientific signifi...

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Problems solved by technology

At present, most of the probes for cysteine ​​(Cys) detection are concentrated in the visible light region or rely on low-sensitivity ultraviolet-visible absorption method detection, and even cannot effectively distinguish cysteine ​​and homocysteine ​​(such as Chinese patent CN105693600A, CN105820810A, CN104447421A, Anal.Chem., 2016, 88(14), pp 7178–7182), because of their fluorescence emission and UV-vis absorption wavelengths are in relatively short wavelength regions, which have serious limitations on biological imaging applications, However, there are few reports on near-infrared small molecule fluorescent probes with high sensitivity, specificity and specificity to detect cysteine ​​(Cys).

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