Istraživanje stabilnosti i SERS učinkovitosti nanočestica zlata pripremljenih u puferu HEPES

master's thesis

• Title (english): Investigation of the stability and SERS efficiency of gold nanoparticles prepared in HEPES buffer
• Author: Nikolina Gudan
• Mentor: Adriana Kenđel (mentor)
• Committee member: Adriana Kenđel (predsjednik povjerenstva)
• Committee member: Željka Soldin (član povjerenstva)
• Committee member: Morana Dulić (član povjerenstva)
• Committee member: Snežana Miljanić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2025, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

UV/VIS i SERS spektroskopijom istražena je stabilnost tijekom vremena i SERS učinkovitost koloidnih nanočestica zlata nastalih reakcijom tetraklorozlatne(III) kiseline i 4-(2-hidroksietil)- 1-piperazinetilensulfonske kiseline (HEPES). Kao modelne molekule korišteni su rodamin 6G (R6G) i (E)-1,2-di(piridin-4-il)eten (BPE). Koloidi zlata pripremljeni su sa i bez dodatka srebrova(I) nitrata te su uspoređeni s koloidima kojima su dodani stabilizatori nanočestica; cetiltrimetilamonijev bromid... More (CTAB), odnosno N,N-di-(3-aminopropil)butan-1,4-diamin (spermin). U svim pripravljenim koloidima najjače pojačanje raspršenja zračenja opaženo je za molekule BPE, zbog karakteristične strukture bez naboja. Molekule R6G daju intenzivne spektre samo u nemodificiranim koloidima zbog elektrostatskog odbijanja pozitivno nabijenih molekula R6G i molekula stabilizatora koje okružuju nanočestice u modificiranim koloidima. CTAB se pokazao kao bolji stabilizirajući agens nanočestica zlata u odnosu na spermin. Dodatak AgNO3 tijekom sinteze koloida rezultira nastankom nanočestica koje intenzivnije pojačavaju raspršenje zračenja, u usporedbi s koloidima bez dodatka srebrova(I) nitrata. Less

Abstract (english)

The UV/VIS and SERS spectroscopy were used to investigate the stability over time and the SERS efficiency of colloidal gold nanoparticles formed by the reaction of tetrachloroauric(III) acid and 4-(2-hydroxyethyl)-1-piperazineethylenesulfonic acid (HEPES). Rhodamine 6G (R6G) and (E)-1,2-di(pyridin-4-yl)ethene (BPE) were used as model molecules. Gold colloids were prepared with and without the addition of silver(I) nitrate and were compared with colloids to which nanoparticle stabilizers... More were added; cetyltrimethylammonium bromide (CTAB) and N,N-di-(3-aminopropyl)butane-1,4-diamine (spermine). In all prepared colloids, the strongest radiation scattering enhancement was observed for BPE molecules, due to their characteristic uncharged structure. R6G molecules give intense spectra only in unmodified colloids due to electrostatic repulsion between positively charged R6G molecules and stabilizer molecules surrounding the nanoparticles in modified colloids. CTAB has been shown to be a better stabilizing agent for gold nanoparticles than spermine. The addition of AgNO3 during the synthesis of the colloids results in nanoparticles that enhance the scattering of radiation more intensely compared to colloids without the addition of silver(I) nitrate. Less

• Keywords: cetiltrimetilamonijev bromid; HEPES; koloid zlata; spermin
• Keywords (english): cetyltrimethylammonium bromide; HEPES; gold collloid; SERS; spermine
• Language: croatian
• URN:NBN: urn:nbn:hr:217:918446
• Study programme: Title: Graduate university studies in chemistry; specializations in: Graduate university studies in chemistry; Course: Graduate university studies in chemistry; Study programme type: university; Study level: graduate; Academic / professional title: sveučilišni/a magistar/magistra kemije (sveučilišni/a magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-03-20 14:21:46