A Chromogenic Probe for Detection of Biologically Important Anions and its Implications for Designing Molecular Logic Gates

Detection of fluoride (F ), acetate (AcO ), and cyanide (CN ) anions is vital from the biological and environmental aspects. In the present contributions, we have introduced a simple Salen-type chromogenic sensor, BEN, to detect these biologically important anions. Changes in UV-visible absorption spectra and color of BEN solution from very pale yellow to pink color are similar for each of these anions and found to be reversible only in the case of F ions in attendance of HSO ions. The estimated limit of detection of BEN solution for detecting F , AcO , and CN anions is found to be below the micromolar (μM) concentration level. Our fabricated handy paper test kit is suitable for qualitatively naked-eye detection of the anions. An immediate quantitative estimation of these important anions is possible using our BEN employing a smartphone, avoiding any costly experimental setup.