prikaz prve stranice dokumenta Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor
No public access
master's thesis
Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor
Zagreb: University of Zagreb, Faculty of Chemical Engineering and Technology, 2019. urn:nbn:hr:149:399309
Zrinski, Ivana
University of Zagreb
Faculty of Chemical Engineering and Technology

Institutional repository: Repository of Faculty of Chemical Engineering and Technology University of Zagreb

Cite this document

Zrinski, I. (2019). Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor (Master's thesis). Zagreb: University of Zagreb, Faculty of Chemical Engineering and Technology. Retrieved from https://urn.nsk.hr/urn:nbn:hr:149:399309

Zrinski, Ivana. "Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor." Master's thesis, University of Zagreb, Faculty of Chemical Engineering and Technology, 2019. https://urn.nsk.hr/urn:nbn:hr:149:399309

Zrinski, Ivana. "Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor." Master's thesis, University of Zagreb, Faculty of Chemical Engineering and Technology, 2019. https://urn.nsk.hr/urn:nbn:hr:149:399309

Zrinski, I. (2019). 'Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor', Master's thesis, University of Zagreb, Faculty of Chemical Engineering and Technology, accessed 17 June 2024, https://urn.nsk.hr/urn:nbn:hr:149:399309

Zrinski I. Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor [Master's thesis]. Zagreb: University of Zagreb, Faculty of Chemical Engineering and Technology; 2019 [cited 2024 June 17] Available at: https://urn.nsk.hr/urn:nbn:hr:149:399309

I. Zrinski, "Evaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor", Master's thesis, University of Zagreb, Faculty of Chemical Engineering and Technology, Zagreb, 2019. Available at: https://urn.nsk.hr/urn:nbn:hr:149:399309

Metadata
TitleEvaluation of antioxidant capacity in wine, pharmaceutical formulations and sirup using Laccasse biosenzor
Title (croatian)Određivanje antioksidativnog kapaciteta u vinu, farmaceutskim proizvodima i sokovima na modificiranom biosenzoru s lakazom
AuthorIvana Zrinski
MentorSanja Martinez (mentor)
MentorKurt Kalcher (komentor)
Committee memberSanja Martinez (predsjednik povjerenstva)
Committee memberPetar Kassal (član povjerenstva)
Committee memberKurt Kalcher (član povjerenstva)
GranterUniversity of Zagreb
Faculty of Chemical Engineering and Technology
Zagreb
Defense date and country2019-07-09, Croatia
Scientific / art field,
discipline and subdiscipline		TECHNICAL SCIENCES
Chemical Engineering
Abstract
A simple and highly sensitive electrochemical biosensor based on laccase immobilized onto a gold nanoparticle/graphene nanoplatelet-modified screen-printed carbon electrode (AuNP/GNPl/SPCE) was developed for the determination of hydroquinone (HQ) and other polyphenolic compounds. The biosensor shows excellent electro-catalytic activity towards oxidation of hydroquinone at a potential of -0.05 V (vs Ag/AgCl, 3M KCl) in phosphate buffer as supporting electrolyte (0.1 M, pH 7.0) using hydrodynamic amperometry. Analytical characteristics uncover that the AuNPs/GNPls/SPCE comprises a wide linear range for the dependence of the signal on hydroquinone concentrations from 4 to 130 μM with a detection limit (3σ) of 1.5 μM. The repeatability (5 measurements, 100 μM hydroquinone) is ±2 % and the reproducibility (5 biosensors, 100 μM hydroquinone) is ±3 %. Interference studies of most common compounds with the determination of hydroquinone demonstrated negligible effects. Finally, the biosensor and the analytical method were applied to the determination of phenolic antioxidant capacity (AOC) in wine and blueberry syrup based on Trolox (6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid) and hydroquinone equivalents. The results were evaluated by using their calibration curves which were satisfactory and agreed well with the results obtained by the reference method Trolox Equivalent Antioxidant Capacity assay (TEAC-Assay).
Abstract (croatian)
Za određivanje hidrokinona (HQ) i drugih fenolnih spojeva razvijen je jednostavan i vrlo osjetljiv elektrokemijski biosenzor na bazi lakaze, imobilizirane na nanočestice zlata u grafenskoj tinti modificiranoj sa 2D grafenskim nanopločicama, u obliku sitotiskane ugljične elektrode (AuNP / GNPl / SPCE). Biosenzor pokazuje izvrsnu elektrokatalitičku aktivnost prema oksidaciji hidrokinona pri potencijalu od -0,05 V (vs Ag / AgCl, 3M KCl) u fosfatnom puferu (0,1 M, pH 7,0) kod mjerenja metodom hidrodinamičke amperometrije. Analitička svojstva otkrivaju da AuNPs / GNPls / SPCE širok linearni odziv s povećanjem koncentracije hidrokinona od 4 do 130 μM, s granicom detekcije (3σ) od 1,5 uM. Ponovljivost (5 mjerenja, 100 μM hidrokinona) je ± 2%, a reproducibilnost (5 biosenzora, 100 μM hidrokinona) je ± 3%. Interferencijska ispitivanja za određivanje hidrokinona u prisutnosti različith spojeva pokazala su minimalne smetnje. Konačno, biosenzor i analitička metoda primijenjeni su za određivanje fenolnog antioksidacijskog kapaciteta (AOC) u vinu, sirupu od borovnice i farmaceutskim proizvodima iskazanog preko ekvivalentata standarda Troloxa (6-hidroksi-2,5,7,8-tetrametilkroman-2-karboksilne kiseline) i hidrokinona. Rezultati su ocijenjeni korištenjem kalibracijskih krivulja koje su dobro korelirale s rezultatima dobivenim primjenom referentne metode “Trolox Equivalent Antioxidant Capacity assay” (TEAC-Assay).
Keywords
Keywords (croatian)
Languageenglish
URN:NBNurn:nbn:hr:149:399309
Study programmeTitle: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry
Course: Advanced materials and technologies
Study programme type: university
Study level: graduate
Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
Type of resourceText
File originBorn digital
Access conditionsClosed access
Terms of useLicence In copyright icon
Created on2022-02-27 22:04:43