| A significant challenge for the scientific community has been the selective and sensitive detection of molecules, particularly from complex molecular systems. Over the last decade, fluorescence has evolved as a dominant tool in the molecular sensor field due to its high sensitivity and selectivity. Thus, fluorescent sensors have found a wide variety of applications in many fields. Currently most fluorescent sensors are obtained empirically with insufficient knowledge of the functional components within the system. Therefore, novel rational approaches are required for the efficient and rapid development of fluorescent sensors.;In this dissertation, we established a new approach assisted by computational chemistry to design fluorescent sensors. The approach is applicable to predict the behavior of a fluorophore-bridge-receptor sensor based on photoinduced electron transfer (PET). Our first designed rhodamine based pH sensor exhibits strong fluorescence under acidic conditions and very weak fluorescence under basic conditions, just as the computations predicted.;The approach was also used to design fluorescent sensors for citrate, malate, and pyruvate, which are important metabolites involved in numerous biological processes. Our rhodamine based carboxylate sensor shows good responses to all three acids with very low detection limit (10-12M) in water and phosphate buffered solution. Also the rhodamine based carboxylate sensor functions as an excellent pH sensor. The anthracene based carboxylate sensor shows good response to citrate, moderate response to malate and poor response to pyruvate in acetone. The behavior of both carboxylate sensors matches the predictions from computations. The designed anthroquinone based carboxylate sensor was supposed to respond only to citrate but so far has not been synthesized. |
