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Item Open Access ANTIMOULD ACTION OF ZIRAM AND IPBC LOADED IN FUNCTIONALISED NANOGELS AGAINST ASPERGILLUS NIGER AND PENICILLIUM CHRYSOGENUM(Materials Advances, 2022) Raimond, Laurine; Halbus, Ahmed F.; Athab, Zahraa H.; Paunov, Vesselin N.We explore the antimould action of zinc bis(dimethyldithiocarbamate) (Ziram) and 3-iodo-2-propynyl N-butylcarbamate (IPBC) encapsulated into nanogel particles with and without surface functionalization with a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDAC). The antimould nanocarriers were based on commercially available polyacrylic copolymeric nanogel. The antimould agents were loaded into the nanogel particles in their swollen state in alkaline media followed by collapsing of the nanogel particles at acidic pH. We treated Aspergillus niger and Penicillium chrysogenum cultures at different concentrations of the nanocarrier-loaded antimould agent. The effect of the surface charge of the antimould agent-loaded nanocarriers was examined in order to gain better understanding of how the electrostatic interaction of the nanocarrier with the cell walls of the mould hyphae and spores impacts its antimould action. Non-coated nanocarriers proved more efficient than PDAC-coated ones in their antimould action for both Ziram and IPBC formulations. Four different methods of application of the antimould nanocarriers were also explored. We found that the application method of the nanogel carrier is crucial for its efficiency and sustained antimould delivery. Pre-mixing the nanogel-formulated Ziram or IPBC with culture media generally produced much better antimould action. Such a strategy can potentially bypass this antimould resistance and lead to novel formulations with highly sustained antimould activity at similar concentrations of the antimould agent. These insights may lead to the development of more efficient antimould treatments at lower concentration of active agent for mould control with potentially substantial economic and environmental benefits.Item Open Access UV LIGHT BLOCKING AND CONVERSION BY POROUS EUROPIUM-DOPED TITANIUM DIOXIDE (TIO2-EU) THIN FILMS FOR POTENTIAL PROTECTION OF PHOTOVOLTAIC DEVICES(Materials Today Chemistry, 2022) Zhumanova, K.; Serik, L.; Molkenova, A.; Atabaev, T.S.In recent years, transparent thin films capable of screening and converting ultraviolet (UV) photons into visible spectrum gained significant interest in the protection of photovoltaic devices.We investigated the optical properties and UV screening capability of europium-doped titanium oxide (TiO2 Eu) thin films deposited by the spin-coating method from a solution precursor for the first time in this study. We showed that TiO2-Eu thin films demonstrate europium concentration-dependent optical properties, and the quantum yield of the optimized sample was found to be ~10.2%. Transmittance and photoluminescence measurements suggested that TiO2 Eu thin film can effectively block UV photons (~30.5% at 320 nm) at glass substrate and convert them to the red emission thanks to 5D0/7Fj (j ¼ 0, 1, 2, 3, and 4) Eu (III) electronic transitions. Photodegradation experiments with methylene blue dye revealed that TiO2 Eu thin films offer better UV protection compared to uncoated samples. We strongly believe that porous TiO2 Eu thin films can be effectively utilized as a UV blocking and light conversion coating.Item Open Access TERBIUM AND BARIUM CODOPED MESOPOROUS SILICA NANOPARTICLES WITH ENHANCED OPTICAL PROPERTIES(Materials Letters, 2022) Zhumanova, Kamila; Akhmetzhanov, Nursalim; Kang, Moon Sung; Molkenova, Anara; Raja, Iruthayapandi Selestin; Kim, Ki Su; Han, Dong-Wook; Atabaev, Timur Sh.In this study, we showed for the first time that barium (Ba) codoping improves the luminescent properties of terbium (Tb)-doped SiO2 nanoparticles (NPs). In particular, the quantum yield (QY) of SiO2-Ba,Tb NPs was found to be ~10.7%, whereas the QY of bare SiO2-Tb NPs was only ~4.3%. Several mechanisms for luminescence enhancement have been proposed. We strongly believe that this methodology can be used to create alternative silica-based NPs with improved optical characteristics.Item Open Access UNCOVERING THE ROLE OF SURFACE-ATTACHED AG NANOPARTICLES IN PHOTODEGRADATION IMPROVEMENT OF RHODAMINE B BY ZNO-AG NANORODS(Nanomaterials, 2022-08-22) Em, Svetlana; Yedigenov, Mussa; Khamkhash, Laura; Atabaev, Shanazar; Molkenova, Anara; Poulopoulos, Stavros G.; Atabaev, Timur Sh.ZnO nanorods decorated with metal nanoparticles have sparked considerable interest in recent years thanks to their suitability for a wide range of applications, such as photocatalysis, photovoltaics, antibacterial activity, and sensing devices. In this study, we prepared and investigated the improved solar-light-assisted photocatalytic activity of ZnO nanorods (NRs) decorated with Ag nanoparticles (NPs) using a conventional rhodamine B (RB) dye as a model water pollutant. We showed that the presence of Ag NPs on the surface of ZnO NRs significantly increases the degradation rate of RB dye (~0.2432 min1) when compared to bare ZnO NRs (~0.0431 min1). The improved photocatalytic activity of ZnO-Ag was further experimentally tested using radical scavengers. The obtained results reveal that ˙OH and ˙O2 radicals are main active species involved in the RB dye photodegradation by ZnO-Ag NRs. It was concluded that efficient charge separation plays a major role in photocatalytic activity improvement.Item Open Access TAU FIBRIL WITH MEMBRANE LIPIDS: INSIGHT FROM COMPUTATIONAL MODELING AND SIMULATIONS(PLOS ONE, 2021-10-15) Barredo, Prechiel A.; Fernandez, Marvin Jose F.; Ambe, Christopher E.; Balanay, Mannix P.The microtubule-binding protein tau has been the center of researches concerning Alzheimer’s disease (AD) due to several clinical trials of β-amyloid therapies failing recently. The availability of the tau fibril structure from AD brain enables computational modeling studies to calculate binding affinities with different ligands. In this study, the tau paired helical filaments (PHF-Tau) (PDB ID: 5O3L) was used as receptor and interactions with the lipids: 3- alpha-cholesterol; 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine; and C18:1 sphingomyelin, were explored with molecular docking, molecular dynamics, and natural bond orbital analysis. Docking sites upon solvation of the protein with transferable interatomic potential- 3 points reveal the amphipathic nature of PHF-Tau and molecular dynamics simulations show that the embedded phosphocholine at the tail side gives high potential energy values with some amino acids forming H-bond interactions.Item Open Access CRACK-FREE AND THICKNESS-CONTROLLABLE DEPOSITION OF TIO2–RGO THIN FILMS FOR SOLAR HARNESSING DEVICES(Coatings, 2022) Khamkhash, Laura; Em, Svetlana; Molkenova, Anara; Hwang, Yoon-Hwae; Atabaev, Timur Sh.The use of thin films consisting of TiO2 and reduced graphene oxide (TiO2–rGO) in solar harnessing devices is gaining momentum thanks to improved charge-transporting characteristics. In this report, we propose a facile spin-coating methodology for the deposition of crack-free and thickness-controllable TiO2–rGO thin films. A range of characterization techniques were utilized to confirm the formation of the TiO2–rGO thin film. Improved charge-transporting properties of TiO2–rGO composite thin films were confirmed by measuring their photoelectrochemical (PEC) activity under simulated solar light illumination. In particular, it was found that the TiO2–rGO composite thin film yielded a better photocurrent response (~151.3 µA/cm2 ) than the bare TiO2 thin film (~71.6 µA/cm2 ) at 1.23 eV vs. the reversible hydrogen electrode (RHE). The obtained results suggested that rGO addition remarkably improves the charge-transporting properties in TiO2 films.Item Open Access HOW GAP DISTANCE BETWEEN GOLD NANOPARTICLES IN DIMERS AND TRIMERS ON METALLIC AND NON-METALLIC SERS SUBSTRATES CAN IMPACT SIGNAL ENHANCEMENT(Nanoscale Advances, 2022) Arbuz, Alexandr; Sultangaziyev, Alisher; Rapikov, Alisher; Kunushpayeva, Zhanar; Bukasov, RostislavThe impact of variation in the interparticle gaps in dimers and trimers of gold nanoparticles (AuNPs), modified with Raman reporter (2-MOTP), on surface-enhanced Raman scattering (SERS) intensity, relative to the SERS intensity of a single AuNP, is investigated in this paper. The dimers, trimers, and single particles are investigated on the surfaces of four substrates: gold (Au), aluminium (Al), silver (Ag) film, and silicon (Si) wafer. The interparticle distance between AuNPs was tuned by selecting mercaptocarboxylic acids of various carbon chain lengths when each acid forms a mixed SAM with 2- MOTP. The SERS signal quantification was accomplished by combining maps of SERS intensity from a Raman microscope, optical microscope images ( 100), and maps/images from AFM or SEM. In total, we analysed 1224 SERS nanoantennas (533 dimers, 648 monomers, and 43 trimers). The average interparticle gaps were measured using TEM. We observed inverse exponential trends for the Raman intensity ratio and enhancement factor ratio versus gap distance on all substrates. Gold substrate, followed by silicon, showed the highest Raman intensity ratio (9) and dimer vs. monomer enhancement factor ratio (up to 4.5), in addition to the steepest inverse exponential curve. The results may help find a balance between SERS signal reproducibility and signal intensity that would be beneficial for future agglomerated NPs in SERS measurements. The developed method of 3 to 1 map combination by an increase in image transparency can be used to study structure–activity relationships on various substrates in situ, and it can be applied beyond SERS microscopy.Item Open Access SURFACE INTERACTIONS AND MECHANISMS STUDY ON THE REMOVAL OF IODIDE FROM WATER BY USE OF NATURAL ZEOLITE-BASED SILVER NANOCOMPOSITES(MDPI AG, 2020-06-12) Inglezakis, Vassilis J.; Satayeva, Aliya R.; Yagofarova, Almira; Tauanov, Zhandos; Meiramkulova, Kulyash; Farrando-Pérez, Judit; Bear, Joseph C.In this work a natural zeolite was modified with silver following two different methods to derive Ag2O and Ag0 nanocomposites. The materials were fully characterized and the results showed that both materials were decorated with nanoparticles of size of 5–25 nm. The natural and modified zeolites were used for the removal of iodide from aqueous solutions of initial concentration of 30–1400 ppm. Natural zeolite showed no affinity for iodide while silver forms were very efficient reaching a capacity of up to 132 mg/g. Post-adsorption characterizations showed that AgI was formed on the surface of the modified zeolites and the amount of iodide removed was higher than expected based on the silver content. A combination of experimental data and characterizations indicate that the excess iodide is most probably related to negatively charged AgI colloids and Ag-I complexes forming in the solution as well as on the surface of the modified zeolites.Item Open Access ENSEMBLE VOTING-BASED MULTICHANNEL EEG CLASSIFICATION IN A SUBJECT-INDEPENDENT P300 SPELLER(MDPI, 2021-11-26) Mussabayeva, Ayana; Jamwal, Prashant Kumar; Akhtar, Muhammad TahirClassification of brain signal features is a crucial process for any brain–computer interface (BCI) device, including speller systems. The positive P300 component of visual event-related potentials (ERPs) used in BCI spellers has individual variations of amplitude and latency that further changse with brain abnormalities such as amyotrophic lateral sclerosis (ALS). This leads to the necessity for the users to train the speller themselves, which is a very time-consuming procedure. To achieve subject-independence in a P300 speller, ensemble classifiers are proposed based on classical machine learning models, such as the support vector machine (SVM), linear discriminant analysis (LDA), k-nearest neighbors (kNN), and the convolutional neural network (CNN). The proposed voters were trained on healthy subjects’ data using a generic training approach. Different combinations of electroencephalography (EEG) channels were used for the experiments presented, resulting in single-channel, four-channel, and eight-channel classification. ALS patients’ data represented robust results, achieving more than 90% accuracy when using an ensemble of LDA, kNN, and SVM on four active EEG channels data in the occipital area of the brain. The results provided by the proposed ensemble voting models were on average about 5% more accurate than the results provided by the standalone classifiers. The proposed ensemble models could also outperform boosting algorithms in terms of computational complexity or accuracy. The proposed methodology shows the ability to be subject-independent, which means that the system trained on healthy subjects can be efficiently used for ALS patients. Applying this methodology for online speller systems removes the necessity to retrain the P300 speller.Item Open Access STUDYING THE EFFECT OF CHONDROITIN SULFATE ON THE PHYSICOCHEMICAL PROPERTIES OF NOVEL GELATIN/CHITOSAN BIOPOLYMER-BASED CRYOGELS(MDPI, 2021-10-27) Kudaibergen, Gulshakhar; Zhunussova, Madina; Mun, Ellina A.; Arinova, Anar; Ogay, VyacheslavThe application of biopolymers in tissue engineering is of a great interest due to of their inherent properties such as cell adhesion, biodegradation, bioavailability, and viscoelasticity. In this study, we synthesized cryogels based on biopolymers of gelatin, chitosan, and chondroitin sulfate by cryopolymerization and studied the effect of chondroitin sulfate on changing the physicochemical properties of cryogels such as pore size, pore volume, density, gel fraction, and biodegradation. A macroporous surface of the synthesized polymers has been investigated by SEM. The glass transition temperatures of the crosslinked cryogels, determined by the DSC method, were higher compared to that of the non-crosslinked cryogel used as a reference. The results of the MTT test showed that aqueous extracts of the prepared cryogels had no toxic effect on rat adipose-derived mesenchymal stem cells. The research in this area is of great importance and provides new insights into novel, effective methods for obtaining biopolymers that can be used as carriers of cells.Item Open Access SUSTAINED IN VITRO AND IN VIVO DELIVERY OF METFORMIN FROM PLANT POLLEN-DERIVED COMPOSITE MICROCAPSULES(Pharmaceutics, 2021-07-09) Meligi, Noha M.; Dyab, Amro K. F.; Paunov, Vesselin N.We developed a dual microencapsulation platform for the type 2 diabetes drug metformin (MTF), which is aimed to increase its bioavailability. We report the use of Lycopodium clavatum sporopollenin (LCS), derived from their natural spores, and raw Phoenix dactylifera L. (date palm) pollens (DPP) for MTF microencapsulation. MTF was loaded into LCS and DPP via a vacuum and a novel method of hydration-induced swelling. The loading capacity (LC) and encapsulation efficiency (EE) percentages for MTF-loaded LCS and MTF-loaded DPP microcapsules were 14.9% ± 0.7, 29.8 ± 0.8, and 15.2% ± 0.7, 30.3 ± 1.0, respectively. The release of MTF from MTF-loaded LCS microcapsules was additionally controlled by re-encapsulating the loaded microcapsules into calcium alginate (ALG) microbeads via ionotropic gelation, where the release of MTF was found to be significantly slower and pH-dependent. The pharmacokinetic parameters, obtained from the in vivo study, revealed that the relative bioavailability of the MTF-loaded LCS-ALG beads was 1.215 times higher compared to pure MTF, following oral administration of a single dose equivalent to 25 mg/kg body weight MTF to streptozotocin (STZ)-induced diabetic male Sprague-Dawley rats. Significant hypoglycemic effect was obtained for STZ-induced diabetic rats orally treated with MTF-loaded LCS-ALG beads compared to control diabetic rats. Over a period of 29 days, the STZ-induced diabetic rats treated with MTF-loaded LCS-ALG beads showed a decrease in the aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides, cholesterol, and low-density lipoprotein-cholesterol (LDL-C) levels, as well as an increase in glutathione peroxidase (GPx) and a recovery in the oxidative stress biomarker, lipid peroxidation (LPx). In addition, histopathological studies of liver, pancreas, kidney, and testes suggested that MTF-loaded LCS-ALG beads improved the degenerative changes in organs of diabetic rats. The LCS-ALG platform for dual encapsulation of MTF achieved sustained MTF delivery and enhancement of bioavailability, as well as the improved biochemical and histopathological characteristics in in vivo studies, opening many other intriguing applications in sustained drug deliveryItem Open Access A CARBON DOT-BASED CO-NANOZYME WITH ALKALINE PHOSPHATASE – MECHANISM AND APPLICATION(RSC Advances, 2021-10-21) Fan, Haiyan; Dukenbayev, Kanat; Sun, Qinglei; Khamijan, Medina; Turdaliyev, Akhrorbek; Ysmaiyl, Alibek; Tassanbiyeva, Aigerim; Ma, Cuiping; Xie, YingqiuElevated levels of alkaline phosphatase (ALP) are associated with bone metastasis, liver cancer, prostate cancer, breast cancer, and many other diseases or stem cell marker. It is therefore of great significance to quantitatively detect the ALP levels by a rapid, highly sensitive, and easy-to-use strip paper test. In the present work, we discovered an enhancement of ALP activity upon the addition of cauliflower-derived carbon dots (CFCDs), which can be applied as a sensor for ALP. The mixed ALP and CFCDs exhibited a typical Michaelis Menten mechanism with increased Vmax and reduced Km compared to ALP alone. High-Resolution Atomic Force Microscopy (HR-AFM) reveals the dimensions of ALP, the CFCDs, and the phosphatase substrate para-nitrophenyl phosphate (pNPP), as well as the potential interactions among them. The role of the CFCDs was identified as the addition of reaction centers to ALP; in other words, a competitive activator. Besides the improved kinetics, the yield of dephosphorylated product was also increased by at least twice upon the addition of CFCDs. Taking advantage of this effect, a portable CFCD-based paper strip assay was developed to achieve sensitive detection of abnormally elevated ALP levels and visualization of cancer stem cells or proteins by phosphatase-conjugated antibodies. Our findings show great promise for disease diagnosis and bioassays related to ALP enhancement that may be used for protein or cell detection.Item Open Access ENHANCED ANTIMICROBIAL ACTION OF CHLORHEXIDINE LOADED IN SHELLAC NANOPARTICLES WITH CATIONIC SURFACE FUNCTIONALITY(MDPI, 2021-09-21) Al-Obaidy, Saba S. M.; Greenway, Gillian M.; Paunov, Vesselin N.We report on an active nanocarrier for chlorhexidine (CHX) based on sterically stabilized shellac nanoparticles (NPs) with dual surface functionalization, which greatly enhances the antimicrobial action of CHX. The fabrication process for the CHX nanocarrier is based on pH-induced co-precipitation of CHX-DG from an aqueous solution of ammonium shellac and Poloxamer 407 (P407), which serves as a steric stabilizing agent. This is followed by further surface modification with octadecyl trimethyl ammonium bromide (ODTAB) through a solvent change to yield cationic surface functionality. In this study, we assessed the encapsulation efficiency and release kinetics of the novel nanocarrier for CHX. We further examined the antimicrobial effects of the CHX nanocarriers and their individual components in order to gain better insight into how they work, to improve their design and to explore the impacts of their dual functionalization. The antimicrobial actions of CHX loaded in shellac NPs were examined on three different proxy microorganisms: a Gram-negative bacterium (E. coli), a yeast (S. cerevisiae) and a microalgae (C. reinhardtii). The antimicrobial actions of free CHX and CHX-loaded shellac NPs were compared over the same CHX concentration range. We found that the non-coated shellac NPs loaded with CHX showed inferior action compared with free CHX due to their negative surface charge; however, the ODTAB-coated, CHX-loaded shellac NPs strongly amplified the antimicrobial action of the CHX for the tested microorganisms. The enhancement of the CHX antimicrobial action was thought to be due to the increased electrostatic adhesion between the cationic surface of the ODTAB-coated, CHX-loaded shellac NPs and the anionic surface of the cell walls of the microorganisms, ensuring direct delivery of CHX with a high concentration locally on the cell membrane. The novel CHX nanocarriers with enhanced antimicrobial action may potentially find applications in dentistry for the development of more efficient formulations against conditions such as gingivitis, periodontitis and other oral infections, as well as enabling formulations to have lower CHX concentrations.Item Open Access ENHANCED ANTIMICROBIAL ACTION OF CHLORHEXIDINE LOADED IN SHELLAC NANOPARTICLES WITH CATIONIC SURFACE FUNCTIONALITY(MDPI, 2021-09-02) Al-Obaidy, Saba S. M.; Greenway, Gillian M.; Paunov, Vesselin N.We report on an active nanocarrier for chlorhexidine (CHX) based on sterically stabilized shellac nanoparticles (NPs) with dual surface functionalization, which greatly enhances the antimicrobial action of CHX. The fabrication process for the CHX nanocarrier is based on pH-induced co-precipitation of CHX-DG from an aqueous solution of ammonium shellac and Poloxamer 407 (P407), which serves as a steric stabilizing agent. This is followed by further surface modification with octadecyl trimethyl ammonium bromide (ODTAB) through a solvent change to yield cationic surface functionality. In this study, we assessed the encapsulation efficiency and release kinetics of the novel nanocarrier for CHX. We further examined the antimicrobial effects of the CHX nanocarriers and their individual components in order to gain better insight into how they work, to improve their design and to explore the impacts of their dual functionalization. The antimicrobial actions of CHX loaded in shellac NPs were examined on three different proxy microorganisms: a Gram-negative bacterium (E. coli), a yeast (S. cerevisiae) and a microalgae (C. reinhardtii). The antimicrobial actions of free CHX and CHX-loaded shellac NPs were compared over the same CHX concentration range. We found that the non-coated shellac NPs loaded with CHX showed inferior action compared with free CHX due to their negative surface charge; however, the ODTAB-coated, CHX-loaded shellac NPs strongly amplified the antimicrobial action of the CHX for the tested microorganisms. The enhancement of the CHX antimicrobial action was thought to be due to the increased electrostatic adhesion between the cationic surface of the ODTAB-coated, CHX-loaded shellac NPs and the anionic surface of the cell walls of the microorganisms, ensuring direct delivery of CHX with a high concentration locally on the cell membrane. The novel CHX nanocarriers with enhanced antimicrobial action may potentially find applications in dentistry for the development of more efficient formulations against conditions such as gingivitis, periodontitis and other oral infections, as well as enabling formulations to have lower CHX concentrations. Keywords: antimicrobial nanocarriers; chlorhexidine; shellac; ODTAB; E. coli; yeast; microalgae; nanoparticles; Poloxamer 407Item Open Access REVIEW: DETECTION AND QUANTIFICATION OF PROTEINS IN HUMAN URINE(Talanta, 2021) Aitekenov, Sultan; Gaipov, Abduzhappar; Bukasov, RostislavExtensive medical research showed that patients, with high protein concentration in urine, have various kinds of kidney diseases, referred to as proteinuria. Urinary protein biomarkers are useful for diagnosis of many health conditions – kidney and cardio vascular diseases, cancers, diabetes, infections. This review focuses on the instrumental quantification (electrophoresis, chromatography, immunoassays, mass spectrometry, fluorescence spectroscopy, the infrared spectroscopy, and Raman spectroscopy) of proteins (the most of all albumin) in human urine matrix. Different techniques provide unique information on what constituents of the urine are. Due to complex nature of urine, a separation step by electrophoresis or chromatography are often used for proteomics study of urine.Item Open Access DETECTION OF RNA VIRUSES FROM INFLUENZA AND HIV TO EBOLA AND SARS-COV-2: A REVIEW(Analytical Methods, 2020-12-07) Bukasov, Rostislav; Dossym, Dina; Filchakova, OlenaRNA-based viruses likely make up the highest pandemic threat among all known pathogens in about the last 100 years, since the Spanish Flu of 1918 with 50 M deaths up to COVID-19. Nowadays, an efficient and affordable testing strategy for such viruses have become the paramount target for the fields of virology and bioanalytical chemistry. The detection of the viruses (influenza, hepatitis, HIV, Zika, SARS, Ebola, SARS-CoV-2, etc.) and human antibodies to these viruses is described and tabulated in terms of the reported methods of detection, time to results, accuracy and specificity, if they are reported. ...Item Open Access REVIEW: DETECTION AND QUANTIFICATION OF PROTEINS IN HUMAN URINE(Talanta, 2020-10-14) Aitekenov, Sultan; Gaipov, Abduzhappar; Bukasov, RostislavExtensive medical research showed that patients, with high protein concentration in urine, have various kinds of kidney diseases, referred to as proteinuria. Urinary protein biomarkers are useful for diagnosis of many health conditions – kidney and cardio vascular diseases, cancers, diabetes, infections. This review focuses on the instrumental quantification (electrophoresis, chromatography, immunoassays, mass spectrometry, fluorescence spectroscopy, the infrared spectroscopy, and Raman spectroscopy) of proteins (the most of all albumin) in human urine matrix. Different techniques provide unique information on what constituents of the urine are. Due to complex nature of urine, a separation step by electrophoresis or chromatography are often used for proteomics study of urine. Mass spectrometry is a powerful tool for the discovery and the analysis of biomarkers in urine, however, costs of the analysis are high, especially for quantitative analysis. Immunoassays, which often come with fluorescence detection, are major qualitative and quantitative tools in clinical analysis. While Infrared and Raman spectroscopies do not give extensive information about urine, they could become important tools for the routine clinical diagnostics of kidney problems, due to rapidness and low-cost. Thus, it is important to review all the applicable techniques and methods related to urine analysis. In this review, a brief overview of each tech nique’s principle is introduced. Where applicable, research papers about protein determination in urine are summarized with the main figures of merits, such as the limit of detection, the detectable range, recovery and accuracy, when available.Item Open Access ENHANCED ANTIMOULD ACTION OF SURFACE MODIFIED COPPER OXIDE NANOPARTICLES WITH PHENYLBORONIC ACID SURFACE FUNCTIONALITY(Biomimetics, 2021-03-15) Henry, Patricia; Halbus, Ahmed F.; Athab, Zahraa H.; Paunov, Vesselin N.Antimould agents are widely used in different applications, such as specialty paints, building materials, wood preservation and crop protection. However, many antimould agents can be toxic to the environment. This work aims to evaluate the application of copper oxide nanoparticles (CuONPs) surface modified with boronic acid (BA) terminal groups as antimould agents. We developed CuONPs grafted with (3-glycidyloxypropyl) trimethoxysilane (GLYMO), coupled with 4-hydroxyphenylboronic acid (4-HPBA), which provided a strong boost of their action as antimould agents. We studied the antimould action of the 4-HPBA-functionalized CuONPs against two mould species: Aspergillus niger (A. niger) and Penicillium chrysogenum (P. chrysogenum). The cis-diol groups of polysaccharides expressed on the mould cell walls can form reversible covalent bonds with the BA groups attached on the CuONPs surface. This allowed them to bind strongly to the mould surface, resulting in a very substantial boost of their antimould activity, which is not based on electrostatic adhesion, as in the case of bare CuONPs. The impact of these BA-surface functionalized nanoparticles was studied by measuring the growth of the mould colonies versus time. The BA-functionalized CuONPs showed significant antimould action, compared to the untreated mould sample at the same conditions and period of time. These results can be applied for the development of more efficient antimould treatments at a lower concentration of active agent with potentially substantial economic and environmental benefitsItem Open Access CARBON DOTS-MEDIATED FLUORESCENT SCAFFOLDS: RECENT TRENDS IN IMAGE-GUIDED TISSUE ENGINEERING APPLICATIONS(MDPI AG, 2021-05-20) Vedhanayagam, Mohan; Raja, Iruthayapandi Selestin; Molkenova, Anara; Atabaev, Timur Sh.; Sreeram, Kalarical Janardhanan; Han, Dong-WookRegeneration of damaged tissues or organs is one of the significant challenges in tissue engineering and regenerative medicine. Many researchers have fabricated various scaffolds to accelerate the tissue regeneration process. However, most of the scaffolds are limited in clinical trials due to scaffold inconsistency, non-biodegradability, and lack of non-invasive techniques to monitor tissue regeneration after implantation. Recently, carbon dots (CDs) mediated fluorescent scaffolds are widely explored for the application of image-guided tissue engineering due to their controlled architecture, light-emitting ability, higher chemical and photostability, excellent biocompatibility, and biodegradability. In this review, we provide an overview of the recent advancement of CDs in terms of their different synthesis methods, tunable physicochemical, mechanical, and optical properties, and their application in tissue engineering. Finally, this review concludes the further research directions that can be explored to apply CDs in tissue engineering.Item Open Access EDITORIAL: FLUORESCENT CARBON-BASED NANOSTRUCTURES FOR BIOIMAGING APPLICATIONS(Frontiers in Chemistry, 2020-09) Atabaev, Timur Sh.; Han, Dong-WookRecently discovered carbon quantum dots (CQDs) and graphene quantum dots (GQDs) with excellent optical properties sparked considerable interest in the scientific community. First of all, these CQDs and GQDs can be conveniently prepared using green protocols from virtually any carbon-rich media making them more attractive compared to other optical materials. Second, the emission spectrum of CQDs and GQDs can be tuned by controlling the reaction parameters or by incorporation of dopant ions. Finally, low-cost, non-toxic, inert, and photostable CQDs and GQDs already exhibited promising results in areas such as bioimaging, sensing and detection, photocatalysis, energy, and security printing.