Density functional theory (DFT) has been developed for the theoretical study of molecular interaction between fluorescent sensors and oil oxidation products. Silver tetraphenylporphyrin (AgTPP) was selected according to its high sensitivity to small oxidation products in oil samples.
The relative energies of the AgTPP-based fluorescent sensor and its complexes are calculated for the ground spin state determination at singlet, triplet, and quintet. Molecular structures, relative energies, charge distribution, and binding energies representing the sensor properties were
analyzed. The calculated binding energies of AgTPP-analytes have shown the following order based on the most stable spin state: nitrogen (N2)< propane (PRO)< trimethylamine (TMA)< propionic aldehyde (PIA) < ethyl acetate (EAC) < hydrogen sulfide (H2S) <
oxygen (O2) < Propyl alcohol (PA) < methyl ethyl ketone (MEK). This theoretical study suggests that an AgTPP-based fluorescent sensor may be useful for the quality assessment of edible vegetable oil and perhaps other food rich in oils.