NMR studija priprave zlatnih nanočestica u prisutnosti citrata

master's thesis

• Title (english): NMR study of gold nanoparticles preparation in presence of citric acid
• Author: Marko Zlodi
• Mentor: Valerije Vrček (mentor)
• Committee member: Valerije Vrček (predsjednik povjerenstva)
• Committee member: Erim Bešić (član povjerenstva)
• Committee member: Tin Weitner (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of organic chemistry); Zagreb
• Defense date and country: 2023-07-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Sve češća upotreba nanočestica u biomedicinske svrhe potaknula je izradu ovog istraživačkog
rada kako bi se obogatilo znanje i razumjeli mehanizmi tijekom priprave istih. Literaturnim
pregledom stvoren je katalog oksidacijskih reakcija limunske kiseline koje mogu dati
potencijalne produkte u sintezi nanočestica. Eksperimentalni dio priprave nanočestica zlata
u prisutnosti limunske kiseline (Turkevicheva metoda) proveden je u sintetskom laboratoriju
Instituta za medicinska istraživanja i medicinu rada u Zagrebu. Snimanje NMR spektara
reakcijskih alikvota provedeno je u Zavadu za organsku kemiju Farmaceutsko –
biokemijskog fakulteta. Proučavanjem NMR spektara reakcijskih smjesa prošireno je
razumijevanje mehanizama oksidacije limunske kiseline i razjašnjena je stabilnost suspenzije
nanočestica zlata u vodi. Najizraženiji signal nusprodukta u svakom snimljenom spektru
odgovara kemijskom pomaku acetona koji nastaje katalitičkom dehidracijom limunske
kiseline. Prisutnost acetona eksperimentalno je dokazana dodavanjem poznatog spoja u
uzorak, čime se pojačao postojeći signal. U spektru osim acetona, u području nižeg
magnetskog polja pojavljuje se prošireni signal koji odgovara limunskoj kiselini u interakciji
s formiranim nanočesticama, odnosno predstavlja „coating agent“ kao što je opisano u radu.
Uz proširenje signala, vidljivi su i signali koji upućuju na oksidacijske međuprodukte opisane
u uvodnom dijelu, a njihovi kemijski pomaci odgovaraju očekivanim 1H signalima. Radi se
o dikarboksiacetonu i acetooctenoj kiselini, koji su dobiveni podešavanjem reakcijskih
uvjeta. Na taj način dokazano je postojanje onečišćenja tijekom sinteze nanočestica.

Abstract (english)

Increased usage of nanoparicles in biomedicine has inspired the making of this research. It's
goal is to enrich the knowledge and improve the understanding of mechanisms during the
shyntesis of nanoparticles. The potencial products of nanoparticles synthesis were chosen
from a list of oxidation reactions of citric acid, compiled by studying the literature. The
experiment consists of two parts. The first part is Turkevich's method of making nanoparticles
in labaratory of Medical research institute in Zagreb, followed by NMR spectroscopy at
Institute for organic chemistry on Faculty of Pharmacy and Biochemistry. The understanding
of oxidation mechanisms of citric acid was expanded and the stability of nanoparticle water
suspension was clarified by analizing the NMR spectrum of reaction mixtures. The most
expressed signal in almost every spectrum corresponds to the chemical shift of acetone, which
is created in catalytic dehydration of citric acid. Presence of acetone was experimentaly
proven by adding the known substance in the sample, which amplified the existing signal.
Except acetone, in lower magnetic field region, the expanding signal appeared which
represents the citric acid in interaction with formed gold nanoparticles, that is „coating agent“
as described in the paper. Besides the expanding signal, there are some discreet signals which
indicate that there are oxidation intermidiate products as described in introductory part and
their chemical shifts correlate with predicted. The molecules in question are
dicarboxyacetone and acetoacetate which are created by modulating the reaction conditions.
All these evidance shows that there are impurities in shyntesis mixture of nanoparticles.

• Keywords: NMR; nanočestice; limunska kiselina
• Keywords (english): NMR; nanoparticles; citric acid
• Language: croatian
• URN:NBN: urn:nbn:hr:163:886724
• Study programme: Title: Pharmacy - integrated undergraduate and graduate - university study; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: sveučilišni magistar farmacije (sveučilišni magistar farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-04-02 11:45:40