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Abstract: Nanomaterials and sensors play an important role in modern technologies, including medical diagnostics and biochemical research. This work presents the possibility of using o-Phthaldialdehyde (OPA) in combination with 3-mercaptopropyltriethoxysilane (MPTES) to develop a dopamine-responsive sensor. During the experiment, these materials were used at different pH and ratios to determine the optimal parameters for obtaining high fluorescence intensity of the reaction product. The data obtained demonstrate a linear relationship between the fluorescence response (λex/λem = 340/460 nm) of OPA/MPTES and dopamine concentration in the range of 0.1–3.0 µM at a pH of 8, and the detection limit was 8.7 nM. The obtained results confirm the potential of OPA/MPTES as a sensing component for the detection of dopamine
Keywords: fluorometric method, dopamine, o-phthalaldehyde
Published in DKUM: 13.03.2025; Views: 0; Downloads: 0
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Abstract: The research aim was to remove as many microfibres, microplastics and harmful bacteria as possible from the polluted water to produce suitable water for reuse. The test water was the effluent from the municipal wastewater treatment plant in Shalek Valley. A pilot plant with a ceramic SiC filter for membrane filtration and ozonation of filtered water was set up to remove suspended solids, micro-fibres, microplastics, and harmful microorganisms. The Microfibers Detection System was developed to identify microfibers on-site. The results showed that the microfiltration system combined with ozone treatment effectively removed total suspended solids, microfibres, microplastics and microorganisms. A detection system method for identifying microfibres and microplastic particles was used to determine how many microfibres and microorganisms were identified by membrane filtration and ozonation. The study showed that membrane filtration successfully removed all microfibres, 88% of total coliforms and 93% of E. coli. After additional ozonation, we achieved a 100% removal rate of total coliforms and a 100% removal rate of E. coli. The treated water (effluent from the municipal wastewater treatment plant) can be used for specific purposes, such as agricultural irrigation or enhancing bathing waters near the plant’s water effluent.
Keywords: microfibres removal, microplastics, microfiltration, ozonation, water reuse
Published in DKUM: 26.09.2024; Views: 0; Downloads: 11
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Abstract: Dopamine is an important hormone and neurotransmitter, and its levels in human fluids can indicate stress, depression, and various mental disorders. Food products, as well as medications, affect its level in the human body greatly. Therefore, dopamine monitoring is crucial, and necessary for improving the quality of life. The priority is to search for simple and environmentally friendly sensor systems for the in vitro detection of dopamine, enabling mass utilization. In this study, we explored the use of o-phthalaldehyde (OPA) as an indicator for the detection of dopamine, with fluorescence in the visible range (λex/λem = 390/455 nm), while direct dopamine fluorescence measurement was in the UV range (λex/λem = 280/320 nm). The longer excitation/emission wavelengths of dopamine-OPA complex, as well as lower detection limits, are useful for developing a simple detection method using LEDs. Three types of poloxamers were tested as additives to improve the fluorescence signal from the reaction between dopamine and OPA. Pluronic F127 led to a 16-fold increase in the fluorescence. Utilizing 4% Pluronic F127 with OPA at pH 7 resulted in a linear response within concentration ranges of dopamine (0.5–3 µM), achieving a limit of detection of 0.015 µM. In contrast, a direct detection of dopamine within the same range exhibited a detection limit of 0.13 µM.
Keywords: fluorometric method, dopamine, O-phthalaldehyde, Pluronic F127
Published in DKUM: 28.05.2024; Views: 317; Downloads: 20
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Abstract: Cilj magistrske naloge, je ugotoviti vpliv predobdelave poliamidnega materiala iz tekstilnega odpada na učinkovitost njegove razgradnje. Razgradnja je potekala z nevtralno hidrolizo, pri čemer smo želeli v rezultatu čim večjo prisotnost monomera ε – kaprolaktam. Uporabili smo vzorce, ki so bili obarvani v svetlih in temnih tonih ter surovi ne-obarvan odpad poliamidne preje. Obarvane vzorce smo pred razgradnjo razbarvali in nato ročno oprali z neionskim pralnim sredstvom (NPS). Surove vzorce smo oprali ročno in industrijsko, prav tako z NPS. Po končani razgradnji smo vzorec ločili na tekočo in trdno fazo ter izvedli analize s FTIR spektroskopijo in LC-MC kromatografijo, da smo videli katera vrsta predobdelave je bila najučinkovitejša pri pridobitvi čim več tekoče faze v rezultatu in čim višjega absolutnega deleža monomera. Najvišji delež monomera je bil pri vzorcu temno obarvane preje, ki smo jo dvakrat razbarvali in nato ročno oprali z NPS in pri surovem vzorcu, ročno opranem in razgrajenem na reaktorju, ki stabilno vzdržuje pogoje razgradnje.
Keywords: poliamid 6, nevtralna hidroliza, tekstilni odpad, recikliranje
Published in DKUM: 02.10.2023; Views: 371; Downloads: 0
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Abstract: Komunalne čistilne naprave so nepogrešljiv del sodobnih strategij čiščenja odpadnih voda. Ena izmed njih je tudi čistilna naprava Veržej, ki deluje že 14 let. Zanimalo nas je, ali ČN še vedno ustreza sodobnim zakonskim smernicam in ali bi bilo mogoče sam proces čiščenja še izboljšati. Slednje smo ugotavljali s pomočjo proučevanja že znanih dejstev in analiz, ki smo jih izvedli v lastni zasedbi. Izsledki so pokazali, da ČN v glavnem še vedno dobro opravlja svoje delo, vendar pa bi bilo določene segmente kljub temu dobro preurediti. Bolje bi se lahko uredilo ravnanje z odpadnim blatom in odvajanje obdelane vode v naravo. Posodabljanje ČN Veržej ovira predvsem skromna količina sredstev, ki se v ta namen usmerjajo, težavo pa predstavlja tudi dejstvo, da objekt ni upravičen do sofinanciranja s strani Evropske unije, saj ne presega mejne kapacitete 2000 PE.
Keywords: Biološko čiščenje, čistilna naprava Veržej, komunalna odpadna voda, učinek čiščenja, izboljšave delovanja ČN, odpadno blato
Published in DKUM: 16.02.2022; Views: 1158; Downloads: 125
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