Self-assembly based chemosensors: some new and few old revisited

This lecture will cover two interesting stories related to sensing of important analytes based on the assembly/disassembly process of small fluorogenic molecules. A new pyrene containing short peptide self-assembles in water to form a self-supporting hydrogel. The system was used to effective and selective sensing of picric acid in sol, gel and solid state in femtogram level. Interaction of picric acid with pyrene and the consequent effects on the emission of pyrene is the key behind the effective sensing. The second part of the lecture will cover some reported aggregation induced emissive systems (AlEgens). A plethora of such AlEgens are reported in literature and many of them are used as chemosensors. A detailed analyses of a series of such reported AlEgens reveals that the emission observed in those systems are generated from the hydrolysed products of the reported molecules and not AlE of the probes. (author)