Water-soluble asymmetric indocyanine fluorescent dye and preparation method thereof

Abstract

The invention discloses a water-soluble asymmetric indocyanine fluorescent dye. A general formula of the dye is as shown in the specification, wherein n is equal to 1, 2 or 3. A preparation method comprises the steps that (1), N-(3,5-2(2-(2-methoxyethoxy) oxethyl) oxethyl) benzyl-2,3,3-trimethyl-5-sulfonic group-3H-indole is synthesized; 2,3,3-trimethyl-5-sulfonic group-3H-indole, organic sylvine, and 3,5-2(2-(2-methoxyethoxy) oxethyl) oxethyl) oxethyl benzylbromide are added to an alcohol solvent in sequence, and conduct backflow reaction for 20-40h under inert gas shielding; the solvent is distilled off after the reaction; column separation is conducted; a red solid product is obtained; and (2), N-carboxyl benzyl-2,3,3-trimethyl-5-sulfonic group-3H-indole, the product and a condensing agent are dissolved in an acetic acid / acetic anhydride mixed solvent; pyridine or pyrimidine is added, and reacts at 60-100 DEG C for 1-6h under the inert gas shielding; ethyl acetate is added after the reaction for dissolving out a precipitate; suction filtration is conducted; the product is separated by taking a methanol / acetonitrile mixed solvent as an eluent, and using a reverse phase silica gel filling separation column; three color strips are obtained; the second color strip is accepted; and the water-soluble asymmetric indocyanine fluorescent dye is obtained.

Description

technical field [0001] The invention belongs to the field of organic chemistry, and in particular relates to a water-soluble asymmetric indocyanine fluorescent dye containing an ether chain structure, and also relates to a preparation method of the fluorescent dye. Background technique [0002] Williams discovered cyanine dyes (also known as cyanines) in 1856. In 1873, Vogel discovered that such dyes had exceptionally sensitive photosensitivity. Since then, cyanine dyes have been used in biological analysis, chemical analysis, spectral sensitization, solar cells, etc. Applied research is changing with each passing day. Cyanine dyes have a wide spectral range (550nm ~ 1200nm), high molar extinction coefficient (up to 10 5 L·mol -1 cm -1 ), high fluorescence quantum yield, high selectivity, and high sensitivity. With the rapid development of biotechnology and fluorescent labeling technology, cyanine dyes have been widely used in the analysis and detection of DNA, protein a...

AI Technical Summary

Problems solved by technology

[0003] However, there are still many deficiencies in water-soluble asymmetric cyanine dyes, such as: 1) the molecular polarity of asymmetric water-soluble indocyanine dyes is usually large, and there are many side reactions during synthesis; by-products have similar polarities, and the separation of products Purification is quite difficult

2) Most of the products on the market rely on foreign imports, which are expensive

In indocyanine dyes, the longer the conjugated methine chain of the molecule, the less stable the dye

Trimethine indocyanine dyes can be stored for four years at 20°C, while symmetrical pentamethine and asymmetric pentamethine indole cyanine dyes are easily changed from blue to purple when exposed to air, and finally disappear; the stability of heptamethine indocyanine dyes worse

The lower the water solubility of the dye, the greater the self-aggregation tendency of the dye in water, which will cause fluorescence quenching, reduce the fluorescence intensity of the dye in water, and reduce the fluorescence quantum yield, which is not conducive to the fluorescent labeling of biomolecules in the water phase.

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