PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Nanostructured Ox-MWCNT-Ppy-Au Electrochemical Sensor for Ultralow Detection of Retrorsine and Evaluation of Its Cytotoxic Effects on Liver Cells(Taylor & Francis Ltd, 2025) Akturk, Ezgi Zekiye; Njjar, Muath; Ata, Melek Tunc; Kaya, Ahmet; Akdogan, Abdullah; Onac, CananThis study presents the development of a novel retrorsine (RTS)-imprinted sensor utilizing oxidized multi-walled carbon nanotubes (Ox-MWCNTs), polypyrrole (PPy), and gold nanoparticles (AuNPs), employing square wave voltammetry for the sensitive and selective detection of RTS which causes oxidative-stress and DNA damage. The fabricated Ox-MWCNT-PPy-AuNP sensor demonstrated a surface-area of (0.218 cm2) is 4.25 times larger than a bare glassy carbon electrode, with a low charge transfer resistance (10.9 Omega), enhancing electron transfer kinetics. The sensor showed excellent sensitivity in detecting retrorsine, with a limit of detection of 0.035 nM in synthetic matrices and -0.030 nM in HepaRG cell culture medium. Toxicity assays in HepaRG cells revealed dose-dependent oxidative-stress, with glutathione levels decreasing from 23.08 +/- 0.21 mu mol/109 to 21.21 +/- 0.02 mu mol/109 at 35 mu M retrorsine. Concurrently, GSSG levels increased from 1.32 +/- 0.26 mu mol/109 to 2.22 +/- 0.02 mu mol/109. DNA-damage assessed via comet assay, showed significant increases in tail-moment (2.53 mu m) and tail-migration (16.13 mu m). Oxidative DNA-damage, indicated by 8-OHdG levels, increased significantly from 0.29 +/- 0.02 ng.mL- (control) to 0.47 +/- 0.07 ng.mL- at 35 mu M retrorsine. These findings demonstrate the sensor's effectiveness for retrorsine detection and its applicability in toxicological studies. The integration of nanomaterial engineering and molecular imprinting provides a highly sensitive, selective, and eco-friendly solution for monitoring toxic agents and assessing their biological impacts.Review Citation - WoS: 5Citation - Scopus: 5Development and Functionalization of Electrospun Fiber Coated Thin Film Microextraction Devices for Rapid Mass Spectrometric Determination of Biologically Important Polar Molecules(Elsevier B.V., 2024) Öztürk,M.; Salih,B.; Eroğlu,A.E.; Boyaci,E.Rapid diagnosis of diseases is one of the challenging areas in clinical research. From the analytical chemist's perspective, the main challenges are isolating the compounds from the bio-specimen and lengthy analysis times. In this regard, solid phase microextraction offers a platform to address the abovementioned challenges. Moreover, its sharp tip-thin film geometry, known as coated blade spray (CBS), can enhance the extraction and act as an ionization source in direct mass spectrometric analysis. In this study, a new CBS device specifically designed for polar analytes was prepared and optimized to determine urinary metabolites. For this purpose, polyacrylonitrile (PAN) was selected as a base polymer as it can be electrospun to form a nanofibrous structure, and it can be modified with weak ion exchange moieties to interact with polar analytes. Following the electrospinning of PAN, hydrolysis was optimized, and conditions leading to sufficient extraction enhancement without dissolving the polymer were obtained when probes were treated with 5.0 M of NaOH for 2.5 h. Using the coated blades prepared as explained, the evaluation of various extraction conditions showed that 5 min is sufficient for equilibrium extraction. In addition, the solution's ionic strength and pH significantly affect the extraction. Optimum sorption was obtained at no salt added and pH 7.0 conditions. The CBS-MS optimization showed that 10.0 µL of ACN/MeOH/H2O (40:40:20, v/v/v) with formic acid kept for 15 seconds on the blade before voltage application leads to the highest signal. The limits of quantification of the analytes are between 50 and 100 ng/mL. © 2024 Elsevier B.V.Article Citation - WoS: 32Citation - Scopus: 32Luminescent Device for the Detection of Oxidative Stress Biomarkers in Artificial Urine(American Chemical Society, 2018) Ammanath, Gopal; Yıldız, Ümit Hakan; Palaniappan, Alagappan; Liedberg, BoA luminescent paper-based device for the visual detection of oxidative stress biomarkers is reported. The device consists of a polyvinylidene fluoride membrane impregnated with poly(3-alkoxy-4-methylthiophene) (PT) for colorimetric detection. 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker associated with oxidative stress, is used as a model system for validating the proposed methodology. The detection strategy is based on monitoring the changes in optical properties of PT associated with its conformational changes upon interaction with an aptamer in the presence and in the absence of 8-OHdG. Fluorometric and colorimetric monitoring revealed linear responses for 8-OHdG concentrations between 50 pM and 500 nM (∼14 pg/mL to 140 ng/mL), with limits of detection of ∼300 pM and ∼350 pM, respectively for (n = 3). Colorimetric responses in artificial urine ascertained rapid, sensitive, and selective detection of 8-OHdG at clinically relevant (pM to nM) concentration levels. Furthermore, the proposed methodology enables point-of-care diagnostics for oxidative stress without requiring sophisticated instrumentation.Article Citation - WoS: 64Citation - Scopus: 82Advanced Backcross Qtl Analysis of a Lycopersicon Esculentum X L. Pennellii Cross and Identification of Possible Orthologs in the Solanaceae(Springer Verlag, 2004) Frary, Anne; Fulton, Theresa M.; Zamir, Dani; Tanksley, Steven D.In this study, the advanced backcross QTL (AB-QTL) mapping strategy was used to identify loci for yield, processing and fruit quality traits in a population derived from the interspecific cross Lycopersicon esculentum E6203 x Lycopersicon pennellii accession LA1657. A total of 175 BC2 plants were genotyped with 150 molecular markers and BC2F1 plots were grown and phenotyped for 25 traits in three locations in Israel and California, U.S.A. A total of 84 different QTLs were identified, 45% of which have been possibly identified in other wild-species-derived populations of tomato. Moreover, three fruit-weight/size and shape QTLs (fs2b.1, fw3.1/fsz3.1 andfs8.1) appear to have putative orthologs in the related solanaceous species, pepper and eggplant. For the 23 traits for which allelic effects could be deemed as favorable or unfavorable, 26% of the identified loci had L. pennellii alleles that enhanced the performance of the elite parent. Alleles that could be targeted for further introgression into cultivated tomato were also identified.