Metalloporphyrin-Based Fluorescent Sensor for the Discrimination of Volatile Organic Compounds Using Density Functional Theory

Abstract

This spectral property of the fluorescent sensors were investigated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The considered silver porphyrin (AgP) was selected as a representative dye for the theoretical study of the fluorescent sensors. The molecular structures of AgP and its complexes were optimized at B3LYP/LANL2DZ basis set. The calculated geometry structures, front-line molecular orbitals, absorption spectra, and electronic structures were analyzed to reveal the molecular reaction between AgP-based fluorescent sensors and volatile organic compounds (VOCs). The energy gaps indicated that the efficient orders of AgP-based fluorescent sensor reacted with volatile organic compounds were shown as O2 < N2 < propane (L3) < propaldehyde (L5) < H2S < propanol (L2) < trimethylamine (L1) < ethyl acetate (L6) < butanone (L4). The calculated results all reveal that the AgP-based fluorescent sensor possesses significant changes (i.e., molecular structure, frontline molecular orbital, and absorption spectra) before and after reacting with volatile organic compounds, which are closely related to the selectivity and sensitivity property of AgP-based fluorescent sensor. Therefore, this study may be useful for the AgP-based fluorescent sensor in a special application region.