Ferdowsi University of Mashhad

About: Ferdowsi University of Mashhad is a education organization based out in Mashhad, Iran. It is known for research contribution in the topics: Population & Catalysis. The organization has 11407 authors who have published 20810 publications receiving 263263 citations.

Highly Dispersed Multiwalled Carbon Nanotubes Decorated with Ag Nanoparticles in Water and Experimental Investigation of the Thermophysical Properties

Abstract: The present study investigates the dispersion stability, viscosity, shear stress, and thermal conductivity of multiwalled carbon nanotubes in the presence of gum arabic (MWCNT-GA) as well as functionalized MWCNT with cysteine (MWCNT-Cys) and silver (MWCNT-Ag). To realize good dispersibility and high thermal enhancement, MWCNT were first functionalized by cysteine and then silver ions covalently attached through the thiol group of cysteine. This efficient technique of using a combination of functional silver and cysteine based on MWCNT was developed to enhance the thermal conductivity of the MWCNT suspension. At every sequential step of modification, chemical functionalization was investigated by Fourier transform infrared and Raman spectroscopy. Transmission electron microscope imaging confirmed distribution of silver nanoparticles on the MWCNT surface. Viscosity, shear stress, and thermal conductivity behavior of MWCNT-GA/water, MWCNT-Cys, and MWCNT-Ag/water suspensions were studied under various tempera...

A selective and sensitive fluorescent aptasensor for detection of kanamycin based on catalytic recycling activity of exonuclease III and gold nanoparticles

Abstract: Kanamycin is an aminoglycoside antibiotic used in human and veterinary medicine Sensitive and selective methods to detect kanamycin residues for food safety and clinical diagnosis are of great interest In this study a fluorescent aptasensor was designed to detect kanamycin based on exonuclease III activity (Exo III), gold nanoparticles (AuNPs) and FAM-Labeled complimentary strand of aptamer (CS) In the absence of kanamycin, aptamer binds to its CS to form a double-stranded DNA (dsDNA) with 3′-overhang end at aptamer and 3′-blunt end at CS The formed dsDNA leaves the surface of AuNPs Upon addition of Exo III, aptamer is recycled from dsDNA and the cycle goes on, leading to a very strong fluorescence emission In the presence of kanamycin, aptamer binds to its target and CS remains on the surface of AuNPs, resulting in a weak fluorescence emission The designed aptasensor showed high selectivity toward aminoglycoside antibiotics, including kanamycin and gentamicin, with a limit of detection (LOD) as low as 321 pM for kanamycin This aptasensor was successfully used to detect kanamycin in milk and serum