1. Study of a sensitive and selective electrochemical biosensor for glucose based on ▫$Bi_2Ru_2O_7$▫ pyrochlore clusters combined with MWCNTsJelena Isailović, Aleksandra Dapčević, Milan Žunić, Matjaž Finšgar, Kristijan Vidović, Nikola Tasić, Samo B. Hočevar, 2025, izvirni znanstveni članek Opis: The development of sensitive, selective, and reliable glucose biosensors remains a persistent challenge in clinical diagnostics. In this study, we exploited the advantageous (electro)catalytic properties of bismuth ruthenate (Bi2Ru2O7) pyrochlore clusters, known for their high surface activity and metallic-like conductivity, and the favorable physicochemical properties of multi-walled carbon nanotubes (MWCNTs) by combining them with glucose oxidase (GOD) in a sensitive and selective disposable glucose biosensor. The integration of Bi2Ru2O7 enabled an enhanced and more reproducible response of the biosensor along with fast and improved communication between the supporting electrode and the upper biosensing layer. The architecture of the biosensor involves the deposition of an MWCNT layer on a ferrocyanide-modified screen-printed carbon electrode (FCN-SPCE), followed by the application of a biorecognition layer including GOD and Bi2Ru2O7 clusters. The voltammetric biosensor showed excellent electroanalytical performance, capable of detecting low glucose concentrations with a detection limit of 40 μM along with a linear response across the examined concentration range of 1.0–20.0 mM. The biosensor exhibited good reproducibility with a relative standard deviation (RSD) of 1.2% and interference-free operation against several of the most common interfering compounds. The practical applicability of the biosensor was demonstrated by the determination of glucose in a real serum sample spiked with different concentrations of glucose.
Ključne besede: glucose sensor, glucose oxidase, Bi2Ru2O7 pyrochlore, multi-walled carbon nanotubes, voltammetry, serum
Objavljeno v DKUM: 20.03.2025; Ogledov: 0; Prenosov: 1
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2. Nanomaterials and their recent applications in impedimetric biosensingZala Štukovnik, Regina Fuchs-Godec, Urban Bren, 2023, pregledni znanstveni članek Opis: Impedimetric biosensors measure changes in the electrical impedance due to a biochemical process, typically the binding of a biomolecule to a bioreceptor on the sensor surface. Nanomaterials can be employed to modify the biosensor's surface to increase the surface area available for biorecognition events, thereby improving the sensitivity and detection limits of the biosensor. Various nanomaterials, such as carbon nanotubes, carbon nanofibers, quantum dots, metal nanoparticles, and graphene oxide nanoparticles, have been investigated for impedimetric biosensors. These nanomaterials have yielded promising results in improving sensitivity, selectivity, and overall biosensor performance. Hence, they offer a wide range of possibilities for developing advanced biosensing platforms that can be employed in various fields, including healthcare, environmental monitoring, and food safety. This review focuses on the recent developments in nanoparticle-functionalized electrochemical-impedimetric biosensors.
Ključne besede: impedimetric biosensor, electrochemical impedance spectroscopy, nanomaterials, metal nanoparticles, carbon nanofibers, carbon nanotubes, graphene oxide, quantum dots
Objavljeno v DKUM: 12.02.2024; Ogledov: 6175; Prenosov: 32
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3. Alignment of carbon nanotubes in nematic liquid crystalsPaul van der Schoot, Vlad Popa-Nita, Samo Kralj, 2008, izvirni znanstveni članek Opis: The self-organizing properties of nematic liquid crystals can be used to aligncarbon nanotubes dispersed in them. Because the nanotubes are so much thinner than the elastic penetration length, the alignment is caused by the coupling of the unperturbed director field to the anisotropic interfacial tension of the nanotubes in the nematic host fluid. In order to relate the degree of alignment of the nanotubes to the properties of the nematic liquid crystal, we treat the two components on the same footing and combine Landau-deGennes free energies for the thermotropic ordering of the liquid crystal and for the lyotropic nematic ordering of carbon nanotubes caused by their mutually excluded volumes. The phase ordering of the binary mixture is analyzed as a function of the volume fraction of the carbon nanotubes, the strength of the coupling and the temperature. We find that the degree of ordering of the nanorods is enslaved by the properties of the host liquid and that it can be tuned by raising or lowering the temperature or by increasing or decreasing their concentration. By comparing the theory to recent experiments, we find the anchoring energy of multiwalled carbon nanotubes to be in the range from 10-10 to 10-7 N m-1.
Ključne besede: liquid crystals, nematic crystals, molecular dynamics, stability, elasticity, carbon nanotubes
Objavljeno v DKUM: 07.06.2012; Ogledov: 2023; Prenosov: 89
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