An Efficient Detection of Formaldehyde in Aqueous Samples Using Perylene Molecular Probe

Formaldehyde is frequently found in aquatic foods as a result of inappropriate storage or unauthorised additions. Identifying toxic formaldehyde in aqueous solutions is essential. Because of the sensitivity and selectivity, formaldehyde detection is still a difficult task. The detection of formaldehyde in water-ethanol mixture is described here using a novel 9-hydrazino-N-(2,5-di-tert-butylphenyl)perylene-3,4-dicarboximide (HPDI) as a sensitive probe. The probe allows for the sensitive and selective detection of formaldehyde contamination in real samples. HPDI shows intramolecular charge transfer (ICT) absorption at 552 nm due to the electron-donating capability of the hydrazino unit. By interacting the hydrazino unit of HPDI with added formaldehyde, there is a decrease in the ICT absorption at 552 nm and increase in the fluorescence intensity at 720 nm. The LOD for the formaldehyde determination found to be 0.11 ppm in UV-visible and 0.38 ppm in fluorescence spectroscopic techniques. The fluorescence quantum yield of the synthesized compound HPDI was found to be 0.9 using the perylene-3,4,9,10-tetracarboxylic acid tetrapotassium salt as reference. More importantly, the probe possessed an excellent selectivity in the detection of formaldehyde in the water-ethanol medium for real samples.