•The simple isatin-based chemosensor HNI was used to construct the molecular-scale Boolean logic states.•Fabrication of logic gates based on the photochemical switches triggered completely by anions.•Reversibility of the dual-anion binding affinity for a potential ‘Write–Read–Erase–Read’ mimic.Anion binding properties of the isatin-based colorimetric HNI sensor ((Z)-3-(hydroxyimino)-5-nitroindolin-2-one) were investigated by UV–vis spectroscopy. Absorption response profiles of HNI varied dramatically for different anionic inputs by controlling the intramolecular charge transfer (ICT). These observations were utilized to construct logic functions of OR, NOR and the complementary INH/IMP sequential circuit. Further, reversible optical switches induced by alternative addition of F− and HSO4− were demonstrated with a ‘Write–Read–Erase–Read’ memory function possessing ‘multi-write’ ability.

In this paper, anion binding and sensing affinity of the simple and easy-to-make salen, a typical class of ligand used comprehensively in metal coordination, was investigated. Results indicated that salophen was both a colorimetric and fluorescent selective chemosensor for fluoride ion, which operated by the anion-induced conformational changes and subsequently excited-state intramolecular proton transfer (ESPT) process. The F--induced quick response, as well as noticeable optical changes, suggested that anion-sensing mechanism maybe help to design and to synthesize the new preferential selective probes for F-.