TICT–ICT state change mechanism based acetate fluorescent sensor act as an “Off–On–Off” switch and logic gate

A novel sensor LX based on the TICT–ICT state change mechanism has been designed and synthesized. The sensor LX can perform as not only an exclusive-NOR (XNOR) logic gate but also an “Off–On–Off” molecular switch triggered by AcO− and H+ ions. By selectivity binding with Y-shape AcO− via double hydrogen bonds, the sensor LX underwent a TICT–ICT state change and induced a dramatic fluorescent response. However, the addition of H+ results in the fluorescence decreasing of LX-AcO−. This “Off–On–Off” switch could be controlled via AcO− and H+ cyclically. Moreover, the sensor LX could instantly detect AcO− in non-aqueous and aqueous solution (water content ≤10%) with specific selectivity and high sensitivity, these sense procedures could not interfered by other coexistent competitive anions (F−, Cl−, Br−, I−, AcO−, H2PO4−, HSO4−, ClO4−, CN−, S2−, HSO3−, citrate). The detection limits was 4.0 × 10−7 M of AcO−, which is quite low for the detection of AcO− ions found in many chemical and biological systems.