Facile green synthesis of samarium sesquioxide nanoparticle as a quencher for biologically active imidazole analogues: Computational and experimental insights

Abstract

A green synthetic approach for the synthesis of nanoparticles (NPs) is important to maintain sustainable development. Here we report the synthesis of samarium sesquioxide (Sm2O3) nanoparticles using an eco-friendly and unconventional method that utilizes pineapple peel extract as a reducing agent and stabilizer. The synthesized Sm2O3 NP was characterized using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The density function theory (DFT) calculation was utilized to examine the various molecular properties of the biological potent imidazole analogues, namely 4-(4-(4-nitrophenyl)-5-(4-(trifluoromethyl)phenyl)-1H-imidazol-2-yl)phenol (NTIP) and 4-(4-(4-nitrophenyl)-5-(4-(trifluoromethyl)phenyl)-1H-imidazol-2-yl)aniline (NTIA) at 6–31 G basis set. The predicted HOMO and LUMO energies revealed that the molecules were chemically active and have a tendency for molecular interactions. The solvatochromic fluorescence behavior of NTIP and NTIA has been studied in different solvents ranging from non-polar to polar. Spectroscopic methods such as absorption and fluorescence methods were used to analyze the interaction of Sm2O3 nanoparticles with NTIP and NTIA. Association strength of these compounds with nanoparticle was estimated and observed that the NTIP has a stronger association with Sm2O3 nanoparticle. Stern-Volmer plots were observed to be linear except for the compounds. The estimation of the quenching rate parameter and fluorescence lifetime affirmed the occurrence of a static quenching mechanism. From the fluorescence data, the binding constants and the number of the binding sites were estimated and the quenching mechanism was driven by the electron transfer process.