Κατεύθυνση Χημεία και Τεχνολογία Περιβάλλοντος
Library of the School of Science

2012-10-26

2012

Τσόκου Αικατερίνη

Αθ. Βαλαβανίδης, Καθηγητής ΕΚΠΑ (επιβλέπων), Ε. Δανεσάκης, Καθηγητής ΕΚΠΑ, Α. Χίσκια, Ερευνήτρια Α', ΕΚΕΦΕ Δημόκριτος

Φωτοκαταλυτική σύνθεση νανοσωματιδίων αργύρου με πολυοξομεταλλικές ενώσεις.Χαρακτηρισμός και μελέτη τοξικότητας.

Greek

The basic aim of present work is the composition, the characterization and the
research of the toxicity of stabilised silver nanoparticles using
polyoxometallates (POMs), in the frames of “green chemistry”, a process at
which are minimised the by-products and remains that are rejected in the
environment. For this reason, polyoxometallates (POMs) were selected as
reductive reaction agents.POMs are well-known for their redox behavior. They
undergo fast, reversible and controlled reduction without significant change in
their structure, so they can oxidize difficult oxidative molecules or they can
reduce difficult reductive molecules.While reoxidating, they can transfer
electrons in metal ions in the solution, causing reduction in M0. The reduced
metal precipitates and can very easily be removed from the solution. Under
conditions however, the metal does not precipitate, but remains in the solution
in colloidal form. In the particular work I managed to do preparation and
stabilisation of silver nanoparticles in aqueous solution, after reduction of
ions Ag+ (AgNO3). Initially, POM is irridated with near UV/Vis radiation (λ>
320 nm). Then, it abstracts electron from 2-propanol (sacrificial reagent) that
it is found in the solution and is reduced, POM (e-), taking the characteristic
blue colour. Then, POM (e-) transfers the electron to the cation and gets
reoxidized. The pictures of Scanning electron microscope (SEM) shows us that
the nanoparticle is capped by POM molecules and is protected. In further
biological analysis as MTT and DCHF-DH we managed to get some results about the
high toxicity of Ag+ in human fibroblasts in comparison with the toxicity of
silver nanoparticles. The toxicity of silver nanoparticles occurred of the
(ROS) which are responsible about oxidative stress of healthy cells.

Silver nanoparticles, Polyoxometallates, Reactive oxidant species, Redox behavior, Blue

Yes

13-18

Yes

249

137

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https://pergamos.lib.uoa.gr/uoa/dl/object/1320713