Barbituric acid appended fluorescent sensor for the detection of Cu2+/Hg2+ ions along with real-life utility in recognition of malathionin food samples and fingerprint imaging

A fluorescent sensor based on barbituric acid has been synthesized via single step reaction and utilized for the detection of metal ions (Cu2+/Hg2+) in aqueous medium. With the incorporation of Cu2+/Hg2+ ions to theCH3OH:H2O (1:1, v/v,pH = 7.0, HEPES buffer) solution of sensor 1, the fluorescence peak at 483 nm quenched remarkably. DFT Computational calculations pointed to the interaction of Cu2+/Hg2+ ions with sensor 1 through keto-enol tautomerism by the means of carbonyl of barbituric acid and –OH of aldehyde present in the sensor molecule. 1H NMR titration experiment was carried out to support the DFT studies. Moreover, the real-world utility of the sensor 1 has been successfully inspected for recognition of pesticide, malathion, in various food samples such as tomato, potato, spinach, apple and orange. Owing to the fluorescent nature of sensor 1, it was utilized for the development of latent fingerprints, which could further be exploited in the field of forensic science.