Agne Sulciute

Bio: Agne Sulciute is an academic researcher from Kaunas University of Technology. The author has contributed to research in topics: Nanorod & Photodegradation. The author has an hindex of 2, co-authored 2 publications receiving 19 citations.

ZnO Nanostructures Application in Electrochemistry: Influence of Morphology

Abstract: The aim of this work was to investigate the influence of morphology on its electrochemical properties by comparing ZnO nanostructures in the forms of tetrapods of different sizes, nanorods, and nan...

Structure, morphology and electrochemical properties of zinc–cobalt oxide films on AISI 304 type steel

Abstract: Zn–Co oxide films were prepared by electrochemical deposition under potentiostatic conditions. The effects of synthesis conditions on structure, morphology, composition and electrochemical properties of deposited films were studied by atomic absorption spectroscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and photovoltammetry analysis. It has been determined that the as-deposited films are lamellar with intercalated acetate ions, consisting of ZnO and α-Co(OH)2 phases. The annealed films retain the same structure without impurities and consist of wurtzite-type ZnO and spinel-type Co3O4. The photoelectrochemical performance and the specific capacitance of the prepared electrodes were evaluated in 0.1 mol × L−1 NaOH aqueous solutions. The obtained experimental results showed that the values of specific capacitance increase with the increase in the amount of cobalt (hydr)oxide. On the contrary, the photoactivity decreases with the increase in cobalt content in the films.

Electrochemical Impedance Spectroscopy (EIS): Principles, Construction, and Biosensing Applications

Abstract: Electrochemical impedance spectroscopy (EIS) is a powerful technique used for the analysis of interfacial properties related to bio-recognition events occurring at the electrode surface, such as antibody-antigen recognition, substrate-enzyme interaction, or whole cell capturing. Thus, EIS could be exploited in several important biomedical diagnosis and environmental applications. However, the EIS is one of the most complex electrochemical methods, therefore, this review introduced the basic concepts and the theoretical background of the impedimetric technique along with the state of the art of the impedimetric biosensors and the impact of nanomaterials on the EIS performance. The use of nanomaterials such as nanoparticles, nanotubes, nanowires, and nanocomposites provided catalytic activity, enhanced sensing elements immobilization, promoted faster electron transfer, and increased reliability and accuracy of the reported EIS sensors. Thus, the EIS was used for the effective quantitative and qualitative detections of pathogens, DNA, cancer-associated biomarkers, etc. Through this review article, intensive literature review is provided to highlight the impact of nanomaterials on enhancing the analytical features of impedimetric biosensors.

Binary photonic crystal for refractometric applications (TE case)

Abstract: In this work, a binary photonic crystal is proposed as a refractometric sensor. The dispersion relation and the sensitivity are derived for transverse electric (TE) mode. In our analysis, the first layer is considered to be the analyte layer and the second layer is assumed to be left-handed material (LHM), dielectric or metal. It is found that the sensitivity of the LHM structure is the highest among other structures. It is possible for LHM photonic crystal to achieve a sensitivity improvement of 412% compared to conventional slab waveguide sensor.

Non-antimicrobial and Non-anticancer Properties of ZnO Nanoparticles Biosynthesized Using Different Plant Parts of <i>Bixa orellana</i>

Abstract: As traditional cancer therapy is toxic to both normal and cancer cells, there is a need for newer approaches to specifically target cancer cells. ZnO nanoparticles can be promising due their biocompatible nature. However, ZnO nanoparticles have also shown cytotoxicity against mammalian cells in some cases, because of which there is a need for newer synthesis approaches for biocompatible ZnO nanoparticles to be used as carrier molecules in drug delivery applications. Here, we report the biosynthesis of ZnO nanoparticles using different plant parts (leaf, seed, and seed coat) of Bixa orellana followed by different characterizations. The UV-visible spectra of ZnO showed absorption maxima at 341 and 353 nm, 378 and 373 nm, and 327 and 337 nm, respectively, before and after calcination corresponding to the band gap energy of 3.636 and 3.513 eV, 3.280 and 3.324 eV, and 3.792 and 3.679 eV for L-ZnO, S-ZnO, and Sc-ZnO, respectively. X-ray diffraction analysis confirmed the formation of hexagonal wurtzite structures. Attenuated total reflectance infrared spectra revealed the presence of stretching vibrations of C-C, C=C, C=O, and NH3+ groups along with C-H deformation involving biomolecules from extracts responsible for reduction and stabilization of nanoparticles. Field emission scanning electron microscopy and transmission electron microscopy images showed spherical and almond-like morphologies of L-ZnO and Sc-ZnO with spherical morphologies, whereas S-ZnO showed almond-like morphologies. The presence of antibacterial activity was observed in L-ZnO against Staphylococcus aureus and Bacillus subtilis, in S-ZnO nanoparticles only against Escherichia coli, and in Sc-ZnO only against Staphylococcus aureus. Uncalcinated ZnO nanoparticles showed weak antibacterial activities, whereas calcinated ZnO nanoparticles showed a non-antibacterial nature. The antifungal activity against different fungi (Penicillium sp., Aspergillus flavus, Fusarium oxysporum, and Rhizoctonia solani) and cytotoxicity against HCT-116 cancer cells were not observed before and after calcination in all three ZnO nanoparticles. The antimicrobial nature and biocompatibility of ZnO nanoparticles were influenced by different parameters of the nanoparticles along with microorganisms and the human cells. Non-antimicrobial properties of ZnO nanoparticles can be treated as a pre-requisite for its biocompatibility due to its inert nature. Thus, biosynthesized ZnO nanoparticles showed a nontoxic nature, which can be exploited as promising alternatives in biomedical applications.

Highly Stable NiCoZn Ternary Mixed-Metal-Oxide Nanorods as a Low-Cost, Non-Noble Electrocatalyst for Methanol Electro-Oxidation in Alkaline Medium

Abstract: There is an imperative necessity to develop low-cost and efficient nanocatalysts as a substitute for expensive and rare noble-metal catalysts such as platinum (Pt) and gold (Au) in overcoming the limitations of carbon monoxide and intermediate poisoning in direct methanol fuel cells (DMFCs). Herein, we report a simple, one-step hydrothermal synthesis of NiCoZn ternary mixed-metal-oxide nanorod (NCZMMO)-modified glassy carbon electrode (NCZMMO/GCE) for DMFC application. The NCZMMO/GCE electrode exhibits outstanding electro-oxidation of methanol (MeOH) at a low onset potential of 0.30 V (vs Ag|AgCl) with a high current density of 414 mA/mg in an alkaline medium (1 M KOH). This outstanding performance of the electrode is ascribed to the synergistic outcome of NCZMMO nanorods, where Ni imparts the electrocatalytic active sites for methanol oxidation reaction (MOR) through its multiple oxidation states while the excellent mechanical and chemical stability of the electrode is attributed to the oxides of Co and Zn. The electrode exhibits outstanding durability with 75% retention even at 5000 s of chronoamperometry analysis in the presence of 0.5 M MeOH, which is far superior to other reported noble-metal electrocatalysts. This superior performance of NCZMMO frontlines it as a promising non-noble, low-cost electrocatalyst for various energy conversion applications.