Fluorescence 'Turn-on' Dual Sensor for Selective Detection of Cd2+ and H2AsO4− in Water.

A multi responsive fluorescent probe, N',2-bis(E-4-(diethylamino)-2-hydroxybenzylidene)hydrazine-1-carbothiohydrazideV(H₂L) has been synthesized through one step condensation method. Probe, H₂L shows 'turn-on' dual sensing properties towards Cd²⁺ and H₂AsO₄⁻ at two distinct wavelength. The probe (H₂L) is spectroscopically characterized and the chemo-sensing mechanism has been demonstrated through ¹H NMR, absorption, steady state and time resolved emission study. The most promising advantage of the probe is its application in the one-pot detection of Cd²⁺ (λ_em = 462 nm) and H₂AsO₄⁻(λ_em = 492 nm) where intense emission appears at two different wavelengths and the observed limit of detection (LOD) of H₂L towards Cd²⁺ and H₂AsO₄⁻ are 2.67 × 10^–8 M and 5.14 × 10^–6 M respectively. Further the 'turn-on' emission property of H₂L towards Cd²⁺ is applied to construct INHIBIT logic gate. [ABSTRACT FROM AUTHOR]