February 19, 2025
Sadegh Karimi

Sadegh Karimi

Academic Rank: Associate professor
Address: Department of Chemistry, Faculty of Nano, Bioscience and Technology
Degree: Ph.D in Chemistry
Phone: 07731222074
Faculty: Faculty of Nano and Biotechnology

Research

Title
Chemometrics-Kinetic spectrophotometric determination of parabens by a AgNPs -based colorimetric sensor using Padina brown macroalgae extract
Type Thesis
Keywords
تيامين، ريبوفلاوين، نانوساختار نقره@نقرهاكسيد
Researchers zahra khosravani (Student) , Maryam Abbasi Tarighat (Primary advisor) , Sadegh Karimi (Advisor)

Abstract

The present study is a first report for one -pot synthesis of Ag@Ag2O nanostructures using brown algal genus Padina extract, as a simple, rapid and economically beneficial method. The surface of synthesized nanostructures was functionalized by L-tryptophan. The combination of localized surface plasmon resonance (LSPR) of colorimetric sensor with partial least square (PLS) regression was used for simultaneous determination of thiamin and riboflavin vitamins. Morphology of hybrid structure of nanostructure was investigated by XRD, FESEM, FTIR, TEM and AFM analysis. UV–visible spectrum revealed two peaks at 450 nm and 270 nm corresponding to LSPR peak of AgNPs and formation of Ag2O, respectively. FESEM analysis revealed the hierarchical flower-like Ag@Ag2O nanostructures. The TEM image shows the formation of core-shell nanostructures. Also, DLS analysis and surface zeta potential spectra illustrated aggregated nature of fabricated nanocomposits in presence of vitamins. The dynamic range of thiamin and riboflavin was achieved in 0.1 M acetate buffer pH 4 and ratio Ag@Ag2O: L-try 1:2. The Ag@Ag2O- β-CD sensor exhibited broad linear range of 0.1- 1.0 μM and 3-350 μM for riboflavin and 0.5- 95 ppb for thiamin with low detection limit of 0.16 μM and 0.48 μM, for riboflavin and thiamin, respectively. Proposed technology was applied for simultaneous determination of vitamins in different samples. The obtained results approved that the selective and sensitive colorimetric detection in conjunction with PLS algorithm guaranties the precise and accurate determination of vitamins in complex mixtures