A reversible and dual responsive sensing approach for determination of ascorbate ion in fruit juice, biological, and pharmaceutical samples by use of available triaryl methane dye and its application to constructing a molecular logic gate and a set/reset memorized device.

Since dyes are available in huge quantities and have the well-established chemistry involved in their synthesis, their use in chemosensing could be continued. In the current study, a new and reversible colorimetric and fluorometric chemosensor based on available triaryl methane dye (brilliant green (BG)) - phosphotungstic acid (PTA) complex has been designed for determination of ascorbate (AscH) ion in water/DMSO (90:10v/v, 1.0mmolL HEPES, pH7.0). The "ON-OFF" fluorescence and colorimetric responses of this ion association complex to AscH were based on a displacement mechanism. For the detection of AscH, the linear ranges achieved for UV-Vis absorbance and fluorescence experiments were 3.9-62.6μmolL and 1.9-85.4μmolL, respectively. The limits of detection for both of them were also calculated to be 0.4 and 0.2μmolL. The proposed method was also successfully utilized for rapid recognition of ascorbate in juice samples, human serum, and the formulation of supplement products. Moreover, the proposed chemosensor capability of functioning as INHIBITION-type sensor with PTA and AscH as chemical inputs was indicated by the investigation of the molecular logic behavior of this chemosensor. Eventually, a sequential memory unit displaying "Write-Read-Erase-Read" function could be integrated based on the reversible and reproducible system.