Anion recognition from the perspectives of fluorescent probes and transmembrane ion transporters

Abstract

The presence of diverse anions in cells of all the living organisms is a ubiquitous reality and these anions play crucial roles in a number of biological systems industrial processes as well as in the environment for the maintenance of essential life processes Recognition of anion is a key event based on several fundamental chemical and biological phenomena such as sensing catalysis and transport Among biologically relevant anions fluoride F 8722 ion is one of the most exciting target owing to its well recognized importance behind miscellaneous health and environmental issues Albeit several analytical techniques are available to recognize F 8722 the development of colorimetric fluorescent probes scores a distinct advantage over other methods because of its direct and prompt detection method and absolutely unambiguous color changes using naked eye Furthermore cascade reactions offer a couple of advantages such as atom economy economy of time and waste generation aspects all of which were together exploited to design relevant fluorescent probes Later on cascade reaction strategy encouraged us to develop off on probes based on NBD amine fluorophore for selective detection of F 8722 The limitation of high response time associated with this probe was overcome by employing another strategy of cascade reaction Very fast response time and improvement of sensitivity was achieved with this strategy for selective detection of F 8722 using fluorescein as a fluorophore Further fluorophore was varied aimed at the improvement of reaction time sensitivity and aqueous solubility facets The mechanism of cascade reaction involved in detection of F 8722 was proved by 1H NMR and HPLC titration and cell permeability followed by ability to detect intracellular F 8722 was also evaluated for all these probes In cells the transport of anions across phospholipid bilayers is an essential phenomenon for maintaining the concentration gradient imperative for signaling and cellular regulation Chloride one of the most important