20.500.12556/DKUM-84035 Vpliv različnih metod priprave površine SPE na adsorpcijo izbranih proteinov za zasnovo biosenzorjev magistrsko delo The influence of different surface preparation methods of SPE on adsorption of selected proteins for biosensor design Eden ključnih korakov pri izdelavi elektrokemijskega biosenzorja je imobilizacija biomolekul (proteinov, encimov, DNK ipd.) na površini delovne elektrode. V zvezi s tem je predobdelava elektrodne površine neizogiben del procesa, še posebej v primeru, ko se uporabljajo komercialno dostopne sitotiskane ogljikove elektrode (angl. screen-printed carbon electrodes, SPCE), ki izkazujejo nekoliko slabšo elektrokemijsko ponovljivost. V magistrski nalogi smo preučili vpliv izbranih metod površinske predobdelave SPCE, kot sta predobdelava s tehniko ciklične voltametrije v H2SO4 in H2O2 ter uporaba pozitivno in negativno nabite plazme kisika, na njene elektrokemijske karakteristike. Preučili smo vpliv teh metod na ponovljivost elektrodnega odziva in na kinetiko adsorpcije dveh najpogosteje uporabljenih proteinov za izdelavo biosenzorjev, in sicer govejega serumskega albumina (angl. bovine serum albumin, BSA) in proteina A. Ugotovili smo, da je vsaka od uporabljenih metod izboljšala elektrokemijsko stabilnost SPCE-elektrod in predvsem pozitivno vplivala na kinetiko adsorpcije obeh proteinov. Rezultati kažejo, da je v vsakem primeru BSA pokazala bolj kompleksno obnašanje v primerjavi s proteinom A, kot najbolj učinkovito metodo za oba proteina pa lahko izpostavimo predobdelavo z uporabo negativne plazme. Pri adsorpciji proteina A smo opazili bolj izrazit padec voltametrijskega odziva v primerjavi z BSA, in sicer za vsako metodo predobdelave površine delovne elektrode. V primeru obeh proteinov se je izkazalo, da je koncentracija 5 in 10 µg/mL zadostna za vzpostavitev stabilne proteinske plasti v povezavi z enourno inkubacijo na SPCE. Glede na izboljšanje elektrokemijske ponovljivosti elektrod, kot tudi izboljšanje adsorpcije obeh modelnih proteinov, lahko zaključimo, da je predobdelava SPCE ključni korak pri izdelavi elektrokemijskih biosenzorjev. One of the key steps in the development of an electrochemical biosensor is the immobilization of biomolecules (proteins, enzymes, DNA, etc.) on the surface of the working electrode. Because of this, the pre-treatment of the electrode surface is a necessary part of the process, especially when commercially available screen-printed carbon electrodes (SPCE), which show a slightly poorer electrochemical reproducibility, are used. In this master's thesis, we studied the influence of selected surface pre-treatment methods of SPCEs, such as cyclovoltammetric treatment in H2SO4 and H2O2 and the use of positive and negative glow discharge, on its electrochemical characteristics. We examined the influence of these pre-treatment methods on the reproducibility of the electrode response and on the adsorption kinetics of the two most commonly used proteins for the construction of biosensors, namely bovine serum albumin (BSA) and protein A. We found that each of the used methods improved the electrochemical stability of the SPCEs, and especially had a positive effect on the adsorption kinetics of both proteins. The results show that in all experiments, BSA showed a more complex behaviour compared to protein A, and we can single out the pre-treatment using negative glow discharge as the most effective method for the adsorption of both proteins. In the case of protein A adsorption, we observed a more pronounced signal attenuation after incubation for each SPCE pre-treatment method compared to BSA. The concentrations of 5 and 10 µg/mL, for both BSA and protein A, are sufficient enough to establish a stable protein layer after a one-hour incubation on the working electrode of the SPCE. Considering the improvement in the electrochemical reproducibility of the SPCEs, as well as the improvement in the adsorption of the two model proteins, we can conclude that SPCE pre-treatment is a key step in the fabrication of electrochemical biosensors. sitotiskane elektrode SPCE adsorpcija proteinov goveji serumski albumin protein A elektrokemijski biosenzorji screen-printed electrodes SPCE protein adsorption bovine serum albumin protein A electrochemical biosensors true true false [I. Konjević] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2023-03-31 11:22:23 2023-05-03 07:51:07 2023-05-17 03:05:52 0000-00-00 00:00:00 2023 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (XII, 46 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.636.23(043.2) 152282627 MAG_Konjevic_Ivan_2023.pdf MAG_Konjevic_Ivan_2023.pdf 1 5095FF0EC93E266D0F6C7F7B64D239BD 366edecc032b36f47c2f0a6f24618172b59666eef022309e0a8dc5bf8908b0ac a2c02a07-e42d-11ed-8db1-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=167010 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0