Benzothiazole-aniline compound used as pH fluorescent probe and preparation method thereof

Abstract

The invention discloses a benzothiazole-aniline compound used as a pH fluorescent probe and a preparation method thereof. The structural formula is shown as a chemical formula (shown in the description) (I), wherein in the formula, R1 is vinyl, acetenyl, styryl, phenylethynyl, biphenyl or perylene base; and R2 and R3 are both hydrogen, methyl or ethyl alkane. The preparation method comprises the following steps of: taking p-bromobenzaldehyde and 2-aminothiophenol as raw materials, and connecting with iodine-containing nitrobenzene derivative through dehydration cyclization reaction and coupling reaction; and generating the pH fluorescent probe benzothiazole-aniline derivative through reductive amination. Rigid structures, such as benzothiazole and phenylethynyl, are introduced into the fluorescent probe; the fluorescent probe is high in fluorescence quantum efficiency, and high in thermal stability and solubility. The probe can detect pH value under strong acid condition by adopting a photoinduced charge transfer mechanism and a conjugate passivation mechanism; and the probe has the characteristics of rapid response, high sensitivity and high selectivity, and has wide application prospect in environment monitoring, ecological protection, disease diagnosis, industrial production and sewage inspection.

Description

technical field [0001] The invention relates to the fields of chemistry and fluorescent probes. Background technique [0002] As a measure of acidity, pH value is an important parameter in environmental protection, human health, biophysiology, chemistry, physics, mining, and industrial production. Especially in industrial production, a large amount of strong acidic industrial wastewater is often produced. Environmental and ecological protection has caused great pressure, so it is of great significance to accurately measure the pH value, especially the pH value of strongly acidic aqueous solutions. [0003] The commonly used methods for measuring pH value mainly include pH test paper measurement method, electrode method and fluorescent probe measurement method. Among them, the pH test paper measurement method has a low degree of accuracy and is greatly affected by subjective factors, which is not conducive to accurate measurement of pH value. Compared with the pH test paper...

AI Technical Summary

Problems solved by technology

However, the measurement range of common pH fluorescent probes is concentrated between 4 and 9. This is because traditional pH fluorescent probes are often based on luminophores that are unstable under strong acidic conditions, such as coumarin or fluorescein, and are sensitive to protons. Concentration is very sensitive, when the proton concentration is low (that is, when the pH is around 7), it will generate a fluorescent signal and reach saturation

Due to the addition of too many proton sensing groups, the few fluorescent probes with fluorescent response under low pH conditions have a non-linear relationship between fluorescence intensity and pH value, so accurate pH measurement cannot be performed, and the selectivity is poor.

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