Design and synthesis of fluorescent molecules for the detection of biologically and environmentally important species

Abstract

Chemosensors are widely used for the detection of biologically and environmentally important substances. Especially cyanide, hydrazine, hypochlorite and gold ions are very important due to their high toxicity and wide usage area in the industry and daily life. Ingestion of toxic cyanide by humans in a certain amount can cause nausea, vomiting, unconsciousness, shock and even death. Similarly, taking hydrazine can have toxic and severe health effects that can cause allergies, nausea, vertigo, temporary blindness, acute poisoning, burns by skin contact or inhalation, and even cancer. When hypochlorite is taken in high amounts, it causes various diseases such as cardiovascular diseases, acute lung injuries, neurodegenerative disorders, Alzheimer, Parkinson, and cancer. Although gold ions have positive effects on the body in low amounts, they can cause some health problems through interactions with proteins, DNA and biomolecules when taken in high levels. Conventional techniques such as electrochemical analysis, chromatography, capillary electrophoresis, potentiometry and ion chromatography, which are instrumental devices used to detect these substances, are time-consuming and require expensive devices and complex operations. On the other hand, fluorescent probes have attracted significant attention due to their excellent sensitivity and selectivity, fast response, inexpensive instrumentation, easy operation, real-time imaging, and possible detection with the naked eye. The triphenylamine, thienothiophene and barbituric acid-based probe TTB enables discriminative detection of cyanide, hydrazine, and hypochlorite in different emission wavelengths. Rhodamine and triphenylamine-based probe RH-TPA enables multi-channel (colourimetric, fluorometric and electrochemical) detection of gold ions and BODIPY, and malononitrile-based probe BOD-CN enables fast, selective and sensitive detection of hypochlorite ions. In this thesis, the preparation of specific probes for fluorescence detection of cyanide, hydrazine, hypochlorite and gold ions were carried out. At the same time, practical applications of the probe molecules have been performed in various water samples, fruit, vegetable and dairy products.