Yazar "Uludag, Inci" seçeneğine göre listele

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    A direct and simple immobilization route for immunosensors by CNBr activation for covalent attachment of anti-leptin: obesity diagnosis point of view
    (Springer Heidelberg, 2022) Uludag, Inci; Sezgintürk, Mustafa Kemal
    Leptin is a peptide hormone produced in adipose tissue that works as an antiobesity hormone by balancing energy intake and expenditure. We aimed to develop an ultrasensitive electrochemical immunosensor based on a novel immobilization technique for the early detection of leptin-related diseases in this work. Although several methods for immobilizing antibodies to the biosensor recognition element are known, it is necessary to utilize novel, cost-effective, and less complicated immobilization procedures. When compared with currently utilized immobilization techniques for leptin measurement, this novel method is more efficient, easy to prepare, and sensitive, with a broad detection range. Indium tin oxide-coated polyethylene terephthalate (ITO-PET) sheets were used as the working electrode. ITO-PET sheets were modified using cyanogen bromide (CNBr) to immobilize the anti-leptin antibody through covalent interactions. Each stage of the proposed biosensors was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) methods, and extensive characterization studies were carried out. The designed biosensor has a wide linear detection range (0.05-100 pg/mL), low limits of detection (LOD) (0.0086 pg/mL) and quantification (LOQ) (0.0287 pg/mL). It was concluded that although it is disposable, the ITO-PET working electrode retains its activity even in repeated studies. In addition, the new immobilization procedure provided by CNBr for the designed biosensor fabrication can be effectively used in other biosensing applications.
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    An ultrasensitive electrochemical immunosensor platform based on disposable ITO electrode modified by 3-CPTMS for early detection of parathyroid hormone
    (Tubitak Scientific & Technological Research Council Turkey, 2019) Uludag, Inci; Sezgintürk, Mustafa Kemal
    Parathyroid hormone (PTH) is a polypeptide containing 84 amino acids secreted by cells of the parathyroid glands. Imbalances of parathyroid levels cause medical problems such as osteoporosis, mental disorders, pancreatitis, kidney stones, cancer, and other symptoms. In this study, we aimed to design an ultrasensitive electrochemical immunosensor for PTH detection. Indium tin oxide (ITO) was used as an electrode for electrochemical impedance spectroscopy (EIS) measurements. ITO sheets were modified by using 3-cyanopropyltrimethoxysilane (3-CPTMS) self-assembled monolayers (SAMs) for immobilizing the anti-PTH antibody via covalent interactions. Cyclic voltammetry (CV) and EIS methods were applied to characterize immobilization steps. Therefore, 1% was selected for an optimal concentration of silane, 10 ng/mL was selected as an optimal concentration of anti-PTH, and 30 and 45 min were selected as optimal incubation times for anti-PTH and PTH, respectively. PTH antigen was determined in the concentration range from 0.05 fg/mL to 150 fg/mL. To detect the analytical characterization of the 3-CPTMS modified immunosensor, linear range, repeatability, reproducibility, Kramers-Kronig transform, and regeneration studies were performed. Also, the shelf life of the developed biosensor was investigated. Finally, real human serum samples were analyzed with the PTH immunosensor. The results showed that the designed biosensor system has high potential for early detection for medical treatments.
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    Fluid-based wearable sensors: a turning point in personalized healthcare
    (Tubitak Scientific & Technological Research Council Turkey, 2023) Vural, Berin; Uludag, Inci; Ince, Bahar; Ozyurt, Canan; Ozturk, Funda; Sezgintürk, Mustafa Kemal
    Nowadays, it has become very popular to develop wearable devices that can monitor biomarkers to analyze the health status of the human body more comprehensively and accurately. Wearable sensors, specially designed for home care services, show great promise with their ease of use, especially during pandemic periods. Scientists have conducted many innovative studies on new wearable sensors that can noninvasively and simultaneously monitor biochemical indicators in body fluids for disease prediction, diagnosis, and management. Using noninvasive electrochemical sensors, biomarkers can be detected in tears, saliva, perspiration, and skin interstitial fluid (ISF). In this review, biofluids used for noninvasive wearable sensor detection under four main headings, saliva, sweat, tears, and ISF-based wearable sensors, were examined in detail. This report analyzes nearly 50 recent articles from 2017 to 2023. Based on current research, this review also discusses the evolution of wearable sensors, potential implementation challenges, and future prospects.
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    Lateral flow assays for food analyses: Food contaminants, allergens, toxins, and beyond
    (Elsevier Sci Ltd, 2023) Ince, Bahar; Uludag, Inci; Demirbakan, Burcak; Ozyurt, Canan; Ozcan, Burcu; Sezgintürk, Mustafa Kemal
    Food safety is a major issue because of the prevalence of pathogens, chemicals, and other potentially harmful substances in food products. Because of this, the creation of a reliable and accessible tool for checking on food quality is essential. In comparison to traditional techniques, lateral flow tests for the identification of food-borne pathogens are more modern, straightforward, and quick. This review examines the use of lateral flow biosensors for the detection of various food contaminants and the labels used to improve the effectiveness of the system. Since LFAs may be carried out by non-specialists, they are well-suited for on-site testing in a variety of food production and distribution environments.
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    The Evaluation of Clinical Applications for the Detection of the Alzheimer's Disease Biomarker GFAP
    (Taylor & Francis Inc, 2024) Ozcelikay-Akyildiz, Goksu; Karadurmus, Leyla; Cetinkaya, Ahmet; Uludag, Inci; Ozcan, Burcu; Unal, Mehmet Altay; Sezgintürk, Mustafa Kemal
    One of the most prevalent neurodegenerative diseases is Alzheimer's disease (AD). The hallmarks of AD include the accumulation of amyloid plaques and neurofibrillary tangles, which cause related secondary diseases, progressive neurodegeneration, and ultimately death. The most prevalent cell type in the human central nervous system, astrocytes, are crucial for controlling neuronal function. Glial fibrillary acidic protein (GFAP) is released from tissue into the bloodstream due to astrocyte breakdown in neurological diseases. Increased levels of GFAP in the serum can function as blood markers and be an effective prognostic indicator to help diagnose neurological conditions early on, from stroke to neurodegenerative diseases. The human central nervous system (CNS) is greatly affected by diseases associated with blood GFAP levels. These include multiple sclerosis, intracerebral hemorrhage, glioblastoma multiforme, traumatic brain injuries, and neuromyelitis optica. GFAP demonstrates a strong diagnostic capacity for projecting outcomes following an injury. Furthermore, the increased ability to identify GFAP protein fragments helps facilitate treatment, as it allows continuous screening of CNS injuries and early identification of potential recurrences. GFAP has recently gained attention due to data showing that the plasma biomarker is effective in identifying AD pathology. AD accounts for 60-70% of the approximately 50 million people with dementia worldwide. It is critical to develop molecular markers for AD, whose number is expected to increase to about 3 times and affect humans by 2050, and to investigate possible targets to confirm their effectiveness in the early diagnosis of AD. In addition, most diagnostic methods currently used are image-based and do not detect early disease, i.e. before symptoms appear; thus, treatment options and outcomes are limited. Therefore, recently developed methods such as point-of-care (POC), on-site applications, and enzyme-linked immunosorbent assay-polymerase chain reaction (ELISA-PCR) that provide both faster and more accurate results are gaining importance. This systematic review summarizes published studies with different approaches such as immunosensor, lateral flow, POC, ELISA-PCR, and molecularly imprinted polymer using GFAP, a potential blood biomarker to detect neurological disorders. Here, we also provide an overview of current approaches, analysis methods, and different future detection strategies for GFAP, the most popular biosensing field.
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    Ultrasensitive and Cost-Effective Detection of Neuropeptide-Y by a Disposable Immunosensor: A New Functionalization Route for Indium-Tin Oxide Surface
    (Mdpi, 2022) Uludag, Inci; Sezgintürk, Mustafa Kemal
    Neuropeptide Y (NPY) is one of the most abundant neuropeptides in the human brain, and its levels in the blood change in neurodegenerative and neuroimmune disorders. This indicates that NPY may serve as a diagnostic and monitoring marker for associated disorders. In this paper, an electrochemical immunosensor was created to detect NPY biomarkers using a novel immobilization technique. The proposed biosensor system enables accurate, specific, cost-effective, and practical biomarker analysis. Indium tin oxide-coated polyethylene terephthalate (ITO-PET) sheets were treated with hexamethylene diisocyanate (HMDC) to covalently immobilize antibodies. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques were used to analyze each step of the biosensors. The proposed NPY biosensor has a broad linear detection range (0.01-100 pg mL(-1)), a low limit of detection (LOD) (0.02968 pg mL(-1)), and a low limit of quantification (LOQ) (0.0989 pg mL(-1)). Atomic force microscopy (AFM) was used to support in the optimization process, study the surface morphology, and visualize it. Studies of repeatability, reproducibility, storage, and Kramers-Kronig transformation were conducted during electrochemical characterization. After analytical experiments, the biosensor's responses to human serum samples were evaluated. According to the obtained data, the error margin is small, and the created biosensor offers a great deal of promise for the clinical measurement of NPY.