Nanočestice srebra kao SERS supstrati za analizu sterigmatocistina

master's thesis

• Title (english): Silver nanoparticles as SERS substrates for sterigmatocystin analysis
• Author: Valentina Vrljić
• Mentor: Snežana Miljanić (mentor)
• Committee member: Snežana Miljanić (predsjednik povjerenstva)
• Committee member: Jasmina Rokov Plavec (član povjerenstva)
• Committee member: Đani Škalamera (član povjerenstva)
• Committee member: Adriana Kenđel (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2020-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U svrhu analize mikotoksina sterigmatocistina (STC) SERS spektroskopijom, istraženi su SERS
supstrati temeljeni na nanočesticama srebra dispergiranim u koloidnoj suspenziji i imobiliziranim
na čvrstom nosaču. Korišteni su svježe pripravljeni koloid srebra, koncentrirani koloid te koloid
agregiran dodatkom anorganskih soli (kalcijeva nitrata, natrijeva klorida), dok su kao čvrsti nosači
za nanošenje srebrovih nanočestica korišteni stakleni filter-papir, staklo tretirano s
fluorovodičnom kiselinom te staklo silanizirano s (3-aminopropil)trimetoksisilanom. Nanočestice
srebra pripravljene su redukcijom srebrova(I) nitrata s trinatrijevim citratom, odnosno
hidroksilamin hidrokloridom. Niti s jednim od istraživanih supstrata nije uočeno pojačanje
Ramanovog raspršenja STC (1×10−5 mol dm−3), što ukazuje da se molekule analita nisu
adsorbirale na površinu nanočestica srebra bez obzira na vrstu supstrata. Privlačne elektrostatske
interakcije između neutralnih molekula analita i sloja aniona na površini nanočestica srebra nisu
bile moguće, niti je nastala kemijska veza između atoma kisika molekule analita i površine
nanočestica srebra. SERS spektar aflatoksina B1 (1×10−5 mol dm−3) također nije opažen.

Abstract (english)

In order to analyze mycotoxin sterigmatocystin (STC) by SERS spectroscopy, SERS substrates
based on silver nanoparticles dispersed in a colloidal suspension and immobilized on a solid
support were investigated. Freshly prepared silver colloid, concentrated colloid and colloid
aggregated by addition of inorganic salts (calcium nitrate, sodium chloride) were used, while glass
filter paper, glass treated with hydrofluoric acid and glass silanized with (3-
aminopropyl)trimethoxysilane were employed as solid carriers for the deposition of silver
nanoparticles. Silver nanoparticles were prepared by reducing silver(I) nitrate with trisodium
citrate or hydroxylamine hydrochloride. Enhancement of Raman scattering of STC (1×10−5 mol
dm−3) was not obtained with any of the investigated substrates, implying that the analyte
molecules were not adsorbed on the silver nanoparticles surface regardless of the substrate type.
Attractive electrostatic interactions between the neutral analyte molecules and the anion layer on
the surface of the silver nanoparticles were not possible, nor was a chemical bond formed between
the oxygen atoms of the analyte molecule and the surface of the silver nanoparticles. The SERS
spectrum of aflatoxin B1 (1×10−5 mol dm−3) was also not observed.

• Keywords: koloid; nanočestice srebra; SERS; sterigmatocistin
• Keywords (english): colloid; SERS; silver nanoparticles; sterigmatocystin
• Language: croatian
• URN:NBN: urn:nbn:hr:217:774039
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2021-09-29
• Created on: 2020-10-13 10:54:56