Optical Chemosensor for Ag+, Fe3+, and Cysteine: Information Processing at Molecular Level

A thiacalix[4]arene based chemosensor 3 bearing two pyrene groups has been synthesized which demonstrates ratiometric sensing with Ag+ and fluorescence quenching with Fe3+ ions in mixed aqueous media. The 'in situ' prepared Ag+ and Fe3+ complexes showed high selectivity toward cysteine. The molecular switching between three chemical inputs (Ag+, Fe3+, cysteine) results in various molecular logic gates which have been integrated sequentially to generate a sequential information processing device.