A developed chromogenic probe for determination of dual analyte with logic gates function and keypad-lock

In the current study, a novel and facile selective colorimetric approach was developed by Eriochrome Black T (EBT) for naked-eye detection and determination of nickel (Ni²⁺) and cyanide (CN⁻) ions in H₂O/DMSO (9:1, v/v) media. The chemosensing behaviour of EBT has been indicated through UV-Vis absorbance spectra, visual colour changes, and FTIR spectra. First, EBT could selectively identify Ni²⁺ over other competitive cation in 90% aqueous media and then, the resulting EBT-Ni²⁺complex was successfully applied for selective colorimetric recognition of CN⁻ based on azo-hydrazone tautomeric skeletons. The detection limit of EBT towards Ni²⁺ and CN⁻ were calculated to be 0.06 µmol L⁻¹ and 0.15 µmol L⁻¹, respectively. These consequences represent an innovative type of nimble chemosensor for manifold target ions using simple colorimetric and sequential detection. When operated by chemical ions Ni²⁺ and CN⁻ can act as an absorbance switch, distinguishing a multi-addressable system. In addition, INVERTER (INV) and INHIBIT (INH) logic gates at different wavelengths and a keypad lock were created by applying chemical ions Ni²⁺ and CN⁻ as two inputs and an absorption mode at 541 nm as an output on the basis of suitable chemical stimuli.