Red‐emitting 4‐methyl coumarin fused barbituric acid as an electrochemical sensor for catechol detection and probe for latent fingerprints

Abstract

Herein, we have reported a red‐emitting 4‐methyl coumarin fused barbituric acid azo dye (4‐MCBA) synthesized by conventional method. Density functional theory (DFT) studies of tautomer compounds were done using (B3LYP) with a basis set of 6‐31G(d,p). NLO analysis has shown that tautomer has mean first‐order hyperpolarisabilities (β) value of 1.8188 × 10−30 esu and 1.0470 × 10−30 esu for azo and hydrazone forms, respectively, which is approximately nine and five times greater than the magnitude of urea. 4‐MCBA exhibited two absorption peaks in the range of 290–317 and 379–394 nm, and emission spectra were observed at 536 nm. CV study demonstrated that the modified 4‐MCBA/MGC electrode exhibited excellent electrochemical sensitivity towards the detection of catechol and the detection limit is 9.39 μM under optimum conditions. The 4‐MCBA employed as a fluorescent probe for the visualisation of LFPs on various surfaces exhibited Level‐I to level‐II LFPs, with low background interference.