Carbohydrate based colorimetric and fluorometric sensors for CU2plus and AU3plus ions in aqueous medium

Abstract

The design and synthesis of functional small organic compounds, specially, colorimetric and fluorometric sensors for selective and sensitive detection of target metal ions have become an active field of research due to widespread applications of metal ions in several fields such as chemistry, bio-medicine, environmental and biological studies. Among these metal ions, copper and gold play crucial role in many pathological and physiological processes. Trace amount of Cu 2+ absorption is necessary for living system towards growth and development but long term intake can cause serious health problems like Parkinson, Alzheimer, prion, Menkes and Wilson s diseases etc. Copper traces are found in items of daily uses such as drinking water, many kinds of food and air consumed by living organism at large scale. The widespread use of copper causes significant environmental pollutant. On the other hand, gold is also an important element due to its anti-inflammatory properties. Gold-based drugs are used for the treatment of diseases like tuberculosis, cancer, HIV, arthritis and malaria as well as gene delivery system in molecular biology techniques. In spite of the importance of gold, the gold species such as gold chloride causes damage to the body organs such as liver, kidneys, spleen and the peripheral nervous system. Furthermore, Au 3+ ions are strongly bound to a certain enzyme and DNA, which cause cell toxicity and DNA cleavage in living organisms. In view of the above, the development of cheap, selective and simple colorimetric/fluorometric sensors for accurate determination of importance ions, such as Cu 2+ and Au 3+ in water, food, pharmaceutical products and biological samples like blood, urine, etc has become a great challenge in analytical chemistry. newlineThough several triazole/imine based fluorescent and colorimetric sensors have been developed but they suffer from poor solubility in water, expensive starting materials, longer response time and interference by other cations or anions.