Visual & reversible sensing of cyanide in real samples by an effective ratiometric colorimetric probe & logic gate...

A novel anion probe 3 (2,4-di-tert-butyl-6-((2(2,4-dinitrophenyl) hydrazono) methyl) phenol) has been unveiled as an effective ratiometric and colorimetric sensor for selective and rapid detection of cyanide. The sensing behavior was demonstrated by UV-vis experiments and NMR studies. This sensory system exhibited prominent visual color change toward cyanide ion over other testing anions in DMSO (90%) solvent, with a 1:1 binding stoichiometry and a detection limit down to 3.6×10(-8) mol L(-1). Sensor reveals specific anti-jamming activity and reversible in the presence of Cu(2+) ions. This concept has been applied to design a logic gate circuit at the molecular level. Further we developed coated graphite electrode using probe 3 as ionophore and studied the performance characteristics of electrode. The sensitivity of ratiometric-based colorimetric assay is below the 1.9 μM, accepted by the World Health Organization as the highest permissible cyanide concentration in drinking water. So it can be applied for both quantitative determination and qualitative supervising of cyanide concentrations in real samples.