چكيده به لاتين
Biogenic amines are small organic molecules that have one or more amine groups in their chemical structure and affect the biological and chemical processes of creatures. Their hormonal properties cause to a vital biological role in the human body. These compounds are found in fresh foods, especially in the resources with high amounts of protein and other food products. Biogenic amines in the body have a determined concentration range and beyond that, they cause effects such as high blood pressure, liver damage, various migraines, and various cancers and prevent detoxification of the body. Biogenic amines such as Cadaverine, Putrescine, Spermidine, and Spermine can seriously have a synergistic effect on body-produced toxins. For example, putrescine can indirectly enhance the toxic effects of other biogenic amines by producing carcinogenic nitrosamines, in this regard, their control, tracking, and accurate measurement of these compounds is very important. In this research, two nanozyme-based sensors including iron/vanadium-based Prussian blue analogue (PBA(V/Fe)) and a vanadium-based metal-organic framework (MOF(V)-47) were designed for the colorimetric detection of putrescine. For improving the kinetics of the enzymatic reaction, insulin and pepsin enzymatic compounds were loaded on PBA(V/Fe) and MOF(V)-47, respectively. The prepared compounds were fully characterized with different spectroscopic, microscopic and electrochemical methods and obtained results confirmed that the presence of the metals with multiple oxidation numbers such as vanadium and iron, along with the presence of natural enzymes, has caused an enhanced catalytic effect. Prepared compounds were applied as efficient catalysts in the production of reactive oxygen species (ROSs) and subsequent oxidation of the chromogenic probes including 3,3',5,5'-Tetramethylbenzidine (TMB) and ortho-phenylenediamine (o-PDA) to produce color products, as well as create a detectable UV-Vis spectrophotometer or the naked eye (visual) analytical signal. The as-prepared nanozymes have promising performance in the oxidation process of chromogenic probes which causes sharp peaks and visible colors. The presence of putrescine as a studied analyte with strong antioxidant properties and trapping of active oxygen radicals reduces the catalytic properties and fading colors as well as decreases the intensity of related UV-Vis peaks. Operational parameters of sensor preparation including the catalysts dosage, chromogenic probe concentration, solution pH, interaction time and oxidizing agent concentration were optimized by on-at the time method. Under optimal conditions, the proposed PBA(V/Fe)-Ins has a very low detection limit of 13.0 nM and a wide linear range from 30.0 nM to 12.0 μM as well as MOF(V)-47/pep has a very low detection limit of 5.5 nM, and a wide linear range from 20.0 nM to 80.0 μM. The proposed sensors showed satisfactory selectivity and reproducibility as well as successfully applied to detect putrescine in real fish samples. The developed method is a promising approach in the field of diagnosis of disease biomarkers and food quality monitorin.
